Fish and Wildlife Service, Interior.
Notice of 12–month petition findings.
We, the U.S. Fish and Wildlife Service (Service), announce three 12–month findings on petitions to list three entities of the greater sage-grouse (
We find that listing the western subspecies of the greater sage-grouse is not warranted, based on determining that the western subspecies is not a valid taxon and thus is not a listable entity under the Act. We note, however, that greater sage-grouse in the area covered by the putative western subspecies (except those in the Bi-State area (Mono Basin), which are covered by a separate finding) are encompassed by our finding that listing the species is warranted but precluded rangewide.
We find that listing the Bi-State population (previously referred to as the Mono Basin area population), which meets our criteria as a distinct population segment (DPS) of the greater sage-grouse, is warranted but precluded by higher priority listing actions. We will develop a proposed rule to list the Bi-State DPS of the greater sage-grouse as our priorities allow, possibly in conjunction with a proposed rule to list the greater sage-grouse rangewide.
The finding announced in the document was made on March 23, 2010.
This finding is available on the Internet at
Brian T. Kelly, Field Supervisor, U.S. Fish and Wildlife Service, Wyoming Ecological Services Office (see
Section 4(b)(3)(B) of the Act (16 U.S.C. 1531
On July 2, 2002, we received a petition from Craig C. Dremann requesting that we list the greater sage-grouse (
On July 14, 2006, Western Watersheds Project filed a complaint in Federal district court alleging that the Service's 2005 12–month finding was incorrect and arbitrary and requested the finding be remanded to the Service. On December 4, 2007, the U.S. District Court of Idaho ruled that our 2005 finding was arbitrary and capricious, and remanded it to the Service for further consideration. On January 30, 2008, the court approved a stipulated agreement between the Department of Justice and the plaintiffs to issue a new finding in May 2009, contingent on the availability of a new monograph of information on the sage-grouse and its habitat (Monograph). On February 26, 2008, we published a notice to initiate a status review for the greater sage-grouse (73 FR 10218), and on April 29, 2008, we published a notice extending the request for submitting information to June 27, 2008 (73 FR 23172). Publication of the Monograph was delayed due to circumstances outside the control of the Service. An amended joint stipulation, adopted by the court on June 15, 2009, required the Service to submit the 12–month finding to the
The western subspecies of the greater sage-grouse (
We received a petition, dated January 24, 2002, from the Institute for Wildlife
We published a 90–day finding on February 7, 2003 (68 FR 6500), that the petition did not present substantial information indicating the petitioned action was warranted based on our determination that there was insufficient evidence to indicate that the petitioned western population of sage-grouse is a valid subspecies or DPS. The petitioner pursued legal action, first with a 60–day Notice of Intent to sue, followed by filing a complaint in Federal district court on June 6, 2003, challenging the merits of our 90–day finding. On August 10, 2004, the U.S. District Court for the Western District of Washington ruled in favor of the Service (Case No. C03-1251P). The petitioner appealed and on March 3, 2006, the U.S. Court of Appeals for the Ninth Circuit reversed in part the ruling of the District Court and remanded the matter for a new 90–day finding (
In a related action, the Service also has made a finding on a petition to list the eastern subspecies of the greater sage-grouse (
On May 28, 1999, we received a petition dated May 14, 1999, from the Northwest Ecosystem Alliance and the Biodiversity Legal Foundation. The petitioners requested that the Washington population of western sage-grouse (
In our documents we have used “Columbia Basin population” rather than “Washington population” because we believe it more appropriately describes the petitioned entity. We published a substantial 90–day finding on August 24, 2000 (65 FR 51578). On May 7, 2001, we published our 12–month finding (66 FR 22984), which included our determination that the Columbia Basin population of the western sage-grouse met the requirements of our policy on DPSs (61 FR 4722) and that listing the DPS was warranted but precluded by other higher priority listing actions. As required by section 4(b)(3)(C) of the Act, we have subsequently made resubmitted petition findings, announced in conjunction with our Candidate Notices of Review, in which we continued to find that listing the Columbia Basin DPS of the western subspecies was warranted but precluded by other higher priority listing actions (66 FR 54811, 67 FR 40663, 69 FR 24887, 70 FR 24893, 74 FR 57803). Subsequent to the March 2006 decision by the court on our 90–day finding on the petition to list the western subspecies of the greater sage-grouse (described above), our resubmitted petition findings stated we were not updating our analysis for the DPS, but would publish an updated finding regarding the petition to list the Columbia Basin population of the western subspecies following completion of the new rangewide status review for the greater sage-grouse.
On January 2, 2002, we received a petition from the Institute for Wildlife Protection requesting that the sage-grouse occurring in the Mono Basin area of Mono County, California, and Lyon County, Nevada, be emergency listed as an endangered distinct population segment (DPS) of
On November 15, 2005, we received a petition submitted by the Stanford Law School Environmental Law Clinic on behalf of the Sagebrush Sea Campaign, Western Watersheds Project, Center for Biological Diversity, and Christians Caring for Creation to list the Mono Basin area population of greater sage-grouse as a threatened or endangered DPS of the greater sage-grouse (
On November 18, 2005, the Institute for Wildlife Protection and Dr. Steven G. Herman sued the Service in U.S. District Court for the Western District of Washington (
On August 23, 2007, the November 2005 petitioners filed a complaint challenging the Service's 2006 finding. After review of the complaint, the Service determined that we would revisit our 2006 finding. The Service entered into a settlement agreement with the petitioners on February 25, 2008, in which the Service agreed to a voluntary remand of the 2006 petition finding, and to submit for publication in the
On April 29, 2008, we published in the
Both the November 2005 and the December 2001 petitions as well as our 2002 and 2006 findings use the term “Mono Basin area” to refer to greater sage-grouse that occur within the geographic area of eastern California and western Nevada that includes Mono Lake. For conservation planning purposes, this same geographic area is referred to as the Bi-State area by the States of California and Nevada (Greater Sage-grouse Conservation Plan for Nevada and Eastern California, 2004, pp. 4–5). For consistency with ongoing planning efforts, we will adopt the “Bi-State” nomenclature hereafter in this finding.
The greater sage-grouse (
Greater sage-grouse are members of the Phasianidae family. They are one of two congeneric species; the other species in the genus is the Gunnison sage-grouse (
Since the publication of the 1957 Check-list, the validity of the subspecies designations for greater sage-grouse has been questioned, and in some cases dismissed, by several credible taxonomic authorities (Johnsgard 1983, p. 109; Drut 1994, p. 2; Schroeder
The Integrated Taxonomic Information System (ITIS), a database representing a partnership of U.S., Canadian, and Mexican agencies, other organizations, and taxonomic specialists designed to provide scientifically credible taxonomic information, lists the taxonomic status of western sage-grouse as “invalid – junior synonym” (ITIS 2010). In an evaluation of the historical classification of the western sage-grouse as a subspecies, Banks stated that it was “weakly characterized” but felt that it would be wise to continue to regard western sage-grouse as taxonomically valid “for management purposes” (Banks, pers. comm. 2000). This statement was made prior to the availability of behavioral and genetic information that has become available since 2000. In addition, Banks' opinion is qualified by the phrase “for Management purposes.” Management recommendations and other considerations must be clearly distinguished from scientific or commercial data that indicate whether an entity may be taxonomically valid for the purpose of listing under the Act.
Although the Service had referred to the western sage-grouse in past decisions (for example, in the 12–month finding for a petition to list the Columbia Basin population of western sage-grouse, 66 FR 22984; May 7, 2001), this taxonomic reference was ancillary to the decision at hand and was not the focal point of the listing action. In other words, when past listing actions were focused on some other entity, such as a potential distinct population segment in the State of Washington, we accepted the published taxonomy for western sage-grouse because that taxonomy itself was not the subject of the review and thus not subject to more rigorous evaluation at the time.
Taxonomy is a component of the biological sciences. Therefore, in our evaluation of the reliability of the information, we considered scientists with appropriate taxonomic credentials (which may include a combination of education, training, research, publications, classification and/or other experience relevant to taxonomy) as qualified to provide informed opinions regarding taxonomy, make taxonomic distinctions, and/or question taxonomic classification.
There is no universally accepted definition of what constitutes a subspecies, and the use of subspecies may vary between taxonomic groups (Haig
In general, higher levels of confidence in the classification of subspecies may be gained through the concurrence of multiple morphological, molecular, ecological, behavioral, and/or physiological characters (Haig
The delineation between eastern and western subspecies is vaguely defined and has changed over time from its original description (Aldrich 1946, p. 129; Aldrich and Duvall 1955 p. 12; AOU 1957, p. 139; Aldrich 1963, pp. 539-541). The boundary between the subspecies is generally described along a line starting on the Oregon–Nevada border south of Hart Mountain National Wildlife Refuge and ending near Nyssa, Oregon (Aldrich and Duvall 1955, p. 12; Aldrich 1963, pp. 539-541). Aldrich described the original eastern and western ranges in 1946 (Aldrich 1946, p. 129), while Aldrich and Duvall (1955, p. 12) and Aldrich (1963, pp. 539-541) described an intermediate form in northern California, presumably in a zone of intergradation between the subspecies. All of Aldrich's citations include a portion of Idaho within the western subspecies' range, but the 1957 AOU designation included Idaho as part of the eastern subspecies (AOU 1957, p. 139).
Our evaluation reveals that a boundary between potential western and eastern subspecies may be drawn multiple ways depending on whether one uses general description of historical placement, by considering topographic features, or in response to the differing patterns reported in studying sage-grouse genetics, morphology, or behavior. In their description of greater sage-grouse distribution, Schroeder
As noted above, the original description of the western subspecies of sage-grouse was based solely on differences in coloration (specifically, reduced white markings and darker feathering on western birds) among 11 museum specimens (10 whole birds, 1 head only) collected from 8 locations in Washington, Oregon, and California (Aldrich 1946, p. 129). By today's standards, this represents an extremely small sample size that would likely
Schroeder (2008, pp. 1-19) examined previously collected morphological data across the species' range from both published and unpublished sources. He found statistically significant differences between sexes, age groups, and populations in numerous characteristics including body mass, wing length, tail length, and primary feather length. Many of these differences were associated with sex and age, but body mass also varied by season. There also were substantial morphometric (size and shape) differences among populations. Notably, however, these population differences were not consistent with any of the described geographic delineations between eastern and western subspecies. For example, sage-grouse from Washington and from Northern Colorado up to Alberta appeared to be larger than those in Idaho, Nevada, Oregon, and California (Schroeder 2008, p. 9). This regional variation was not consistent with differences in previously established genetic characteristics (Oyler-McCance
The only data available with respect to behavior are for strutting behavior on leks, a key component of mate selection. One recent study compared the male strut behavior between three sage-grouse populations that happen to include populations from both sides of the putative eastern-western line (Taylor and Young 2006, pp. 36-41). However, the classification of these populations changes depending on the description of western sage-grouse used. The Lyon/Mono population falls within the intermediate zone identified by Aldrich and Duvall (1955, p. 12) but would be classified as eastern under Aldrich (1963, p. 541). The Lassen population may be considered either western (Aldrich 1946, p. 129) or intermediate (Aldrich and Duvall 1955, p. 12; Aldrich 1963, p. 541). The Nye population falls within the range of the eastern sage-grouse (Aldrich and Duvall 1955, p. 12; Aldrich 1963, p. 541). The researchers found that male strut rates were not significantly different between populations, but that acoustic components of the display for the Lyon/Mono and Lassen populations (considered intermediate and/or western) were similar to each other, whereas the Nye population (eastern) was distinct. We consider these results inconclusive in distinguishing between eastern and western subspecies because of the inconsistent results and limited geographic scope of the study.
Schroeder (2008, p. 9) also examined previously collected data on strutting behavior on leks, including Taylor and Young (2006). He noted that, although there was regional variation in the strut rate of sage-grouse, it was not clear if this variation reflected population-level effects or some other unexplained variation. Based on the above limited information, we do not consider there to be any strong evidence of a clear separation of the western sage-grouse from other populations on the basis of behavioral differences.
Genetic research can sometimes augment or refine taxonomic definitions that are based on morphology or behavior or both (discussed in Haig
The AOU has not revisited the question of whether the eastern and western subspecies are valid since their original classification in 1957. We have examined the best scientific information available regarding the putative subspecies of the greater sage-grouse and have considered multiple lines of evidence for the potential existence of western and eastern subspecies based on geographic, morphological, behavioral, and genetic data. In our evaluation, we looked for any consistent significant differences in these characters that might support recognition of the western or eastern sage-grouse as clear, discrete, and diagnosable populations, such that either might be considered a subspecies.
As described above, the boundaries distinguishing the two putative subspecies have shifted over time, and there does not appear to be any clear and consistent geographic separation between sage-grouse historically described as “eastern” and “western.” Banks (1992) and Schroeder (2008, p. 9) both found morphological variations between individuals and populations, but Banks stated that the differences would not be sufficient to recognize
Because the best scientific and commercial information do not support the taxonomic validity of the purported eastern or western subspecies, our analysis of the status of the greater sage-grouse (below) does not address considerations at the scale of subspecies. (See Findings section, below, for our finding on the petition to list the western subspecies of the greater sage-grouse.)
Greater sage-grouse depend on a variety of shrub-steppe habitats throughout their life cycle, and are considered obligate users of several species of sagebrush (e.g.,
During the spring breeding season, male sage-grouse gather together to perform courtship displays on areas called leks. Areas of bare soil, short-grass steppe, windswept ridges, exposed knolls, or other relatively open sites typically serve as leks (Patterson 1952, p. 83; Connelly
Leks range in size from less than 0.04 hectare (ha) (0.1 acre (ac)) to over 36 ha (90 ac) (Connelly
Females have been documented to travel more than 20 km (12.5 mi) to their nest site after mating (Connelly
Productive nesting areas are typically characterized by sagebrush with an understory of native grasses and forbs, with horizontal and vertical structural diversity that provides an insect prey base, herbaceous forage for pre-laying and nesting hens, and cover for the hen while she is incubating (Gregg 1991, p. 19; Schroeder
Sage-grouse clutch size ranges from 6 to 9 eggs with an average of 7 eggs (Connelly
Little information is available on the level of productivity (number of chicks per hen that survive to fall) that is necessary to maintain a stable population (Connelly
Hens rear their broods in the vicinity of the nest site for the first 2–3 weeks following hatching (within 0.2–5 km (0.1–3.1 mi)), based on two studies in Wyoming (Connelly
All sage-grouse gradually move from sagebrush uplands to more mesic areas (moist areas such as streambeds or wet meadows) during the late brood-rearing period (3 weeks post-hatch) in response to summer desiccation of herbaceous vegetation (Connelly
As vegetation continues to desiccate through the late summer and fall, sage-grouse shift their diet entirely to sagebrush (Schroeder
Many populations of sage-grouse migrate between seasonal ranges in response to habitat distribution (Connelly
Sage-grouse typically live between 3 and 6 years, but individuals up to 9 years of age have been recorded in the wild (Connelly
Sage-grouse are dependent on large areas of contiguous sagebrush (Patterson 1952, p. 48; Connelly
Sagebrush is typically divided into two groups, big sagebrush and low sagebrush, based on their affinities for
All species of sagebrush produce large ephemeral leaves in the spring, which persist until reduced soil moisture occurs in the summer. Most species also produce smaller, over-wintering leaves in the late spring that last through summer and winter. Sagebrush have fibrous tap root systems, which allow the plants to draw surface soil moisture, and also to access water deep within the soil profile when surface water is limited (West and Young 2000, p. 259). Most sagebrush flower in the fall. However, during years of drought or other moisture stress, flowering may not occur. Although seed viability and germination are high, seed dispersal is limited. Sagebrush seeds, depending on the species, remain viable for 1 to 3 years. However, Wyoming big sagebrush seeds do not persist beyond the year of their production (West and Young 2000, p. 260).
Sagebrush is long-lived, with plants of some species surviving up to 150 years (West 1983, p. 340). They produce allelopathic chemicals that reduce seed germination, seedling growth, and root respiration of competing plant species and inhibit the activity of soil microbes and nitrogen fixation. Sagebrush has resistance to environmental extremes, with the exception of fire and occasionally defoliating insects (e.g., webworm (
Plants associated with the sagebrush understory vary, as does their productivity. Both plant composition and productivity are influenced by moisture availability, soil characteristics, climate, and topographic position (Miller
Very little sagebrush within its extant range is undisturbed or unaltered from its condition prior to EuroAmerican settlement in the late 1800s (Knick
Greater sage-grouse require large, interconnected expanses of sagebrush with healthy, native understories (Patterson 1952, p. 9; Knick
Prior to settlement of western North America by European immigrants in the 19th century, greater sage-grouse occurred in 13 States and 3 Canadian provinces—Washington, Oregon, California, Nevada, Idaho, Montana, Wyoming, Colorado, Utah, South Dakota, North Dakota, Nebraska, Arizona, British Columbia, Alberta, and Saskatchewan (Schroeder
Sage-grouse have been extirpated from Nebraska, British Columbia, and possibly Arizona (Schroeder
Sage-grouse distribution is associated with sagebrush (Schroeder
Sagebrush occurs in two natural vegetation types that are delineated by temperature and patterns of precipitation (Miller
Due to differences in the ecology of sagebrush across the range of the greater sage-grouse, the Western Association of Fish and Wildlife Agencies (WAFWA) delineated seven Management Zones (MZs I-VII) based primarily on floristic provinces (Figure 2; Table 1; Stiver
As stated above, due to the variability in habitat conditions, sage-grouse are not evenly distributed across the range (Figure 1). The MZs I, II, IV, and V encompass the core populations of greater sage-grouse and have the highest reported densities (Table 2, Figures 1, 2; Stiver
Greater sage-grouse extant habitats have multiple surface ownerships, as reflected in Table 3. Most of the habitats occur on Federal surfaces, a reflection of land disposal practices during EuroAmerican settlement of the western United States (Knick in press, pp. 5-10). Lands dominated by sagebrush that were disposed to private ownership typically had deeper soils and greater available water capacity or access to water (valley bottoms), reflecting their capacity for agricultural development or increased grazing activities (Knick in press, p. 15). The lands remaining in Federal ownership were of poorer overall quality. The resulting low productivity on Federal surfaces affects their ability to recover from disturbance (Knick in press, p. 17).
Federal agencies manage almost two-thirds of the sagebrush habitats (Table 3). The Bureau of Land Management (BLM) manages just over half of sage-grouse habitats, while the U.S. Forest Service (USFS) is responsible for management of approximately 8 percent of sage-grouse habitat (Table 3). Other Federal agencies, including the Service, Bureau of Indian Affairs (BIA), Bureau of Reclamation (BOR), National Park Service (NPS), Department of Defense (DOD), and Department of Energy (DOE) also are responsible for sagebrush habitats, but at a much smaller scale (Table 3). State agencies manage approximately 5 percent of sage-grouse habitats.
Estimates of greater sage-grouse abundance were mostly anecdotal prior to the implementation of systematic surveys in the 1950s (Braun 1998, p. 139). Early reports suggested the birds were abundant throughout their range, with estimates of historical populations ranging from 1,600,000 to 16,000,000 birds (65 FR 51580, August 24, 2000). However, concerns about extinction were raised in early literature due to market hunting and habitat alteration (Hornaday 1916, pp. 181-185). Following a review of published literature and anecdotal reports, Connelly
Population numbers are difficult to estimate due to the large range of the species, physical difficulty in accessing some areas of habitat, the cryptic coloration and behavior of hens (Garton
Braun (1998, p. 141) estimated that the minimum 1998 rangewide spring population numbered about 157,000 sage-grouse, derived from numbers of males counted on leks. The same year, State wildlife agencies within the range of the species estimated the population was at least 515,000 based on lek counts and harvest data (Warren 2008, pers. comm.). In 2000, we estimated the rangewide abundance of sage-grouse was between a minimum of 100,000 (taken from Braun 1998, p. 141) up to 500,000 birds (based on harvest data from Idaho, Montana, Oregon, and Wyoming, with the assumption that 10 percent of the population is typically harvested) (65 FR 51578, August 24, 2000). In 2003, based on increased lek survey efforts, Connelly
Although population numbers are difficult to estimate, the long-term data collected from counting males on leks provides insight to population trends. Periods of historical decline in sage-grouse abundance occurred from the late 1800s to the early-1900s (Hornaday 1916, pp. 179-221; Crawford 1982, pp. 3-6; Drut 1994, pp. 2-5; WDFW 1995; Braun 1998, p. 140; Schroeder
Using lek counts as an index for abundance, Connelly
In 2008, WAFWA conducted new population trend analyses that incorporated an additional 4 years of data beyond the Connelly
Although the MZs were not formally adopted by WAFWA until 2006, the population trend analyses conducted by Connelly
Differences in the MZ trends observed between the three analyses are minimal, with the exception of MZs III, V, and VII. While the results of Connelly
The difference in the annual rate of change between Connelly
In addition to calculating annual rates of change by MZ, Garton
In summary, since neither presettlement nor current numbers of sage-grouse are accurately known, the actual rate and magnitude of decline since presettlement times is uncertain. However, three groups of researchers using different statistical methods (but the same lek count data) concluded that rangewide greater sage-grouse have experienced long-term population declines in the past 43 years, with that decline lessening in the past 22 years. Many of these declines are the result of loss of leks (WAFWA 2008, p. 51), indicating either a direct loss of habitat or habitat function (Connelly and Braun 1997, p. 2). A recent increase in the annual rate of change for MZ VII may simply be an anomaly of small population numbers, as other indicators suggest this area is suffering habitat losses. A delayed response of sage-grouse to changes in carrying capacity was identified by Garton
Greater sage-grouse are a landscape-scale species, requiring large expanses of sagebrush to meet all seasonal habitat requirements. The loss of habitat from fragmentation and conversion decreases the connectivity between seasonal habitats potentially resulting in the loss of the population (Doherty
Analyses of connectivity of greater sage-grouse across the sagebrush landscape were conducted by Knick and Hanser (in press, entire). Knick and Hanser (in press, p. 29) found that the average movement between population centers (leks) of sage-grouse rangewide was 16.6 km (10.3 mi), with a standard deviation of 7.3 km (4.5 mi). Leks within 18 km (11.2 mi) of each other had common features when compared to leks further than this distance (Knick and Hanser in press, p. 17). Therefore, they used a distance of 18 km (11.2 mi) between leks to assess connectivity (movement between populations), but cautioned that this distance may not accurately reflect genetic flow, or lack thereof, between populations (Knick and Hanser in press, p. 28). Genetic evidence suggests that exchange of individual birds has not been restricted, although there is a gradation of allelic frequencies across the species' range (Oyler-McCance and Quinn, in press, p. 14). This result suggests that widespread movements (e.g., across several States) are not occurring.
Population linkages primarily occurred within MZs, and connectivity between MZs was limited, with the exception of MZs I (Great Plains) and II (Wyoming Basin). Within MZs, the Wyoming Basin (MZ II) had the highest levels of connectivity, followed by MZ IV (Snake River Plain) and MZ I (Great Plains) (Knick and Hanser in press, p. 18). The MZ VI (Columbia Basin) and VII (Colorado Plateau) had the least internal connectivity, suggesting there was limited dispersal between leks and an existing relatively high degree of isolation (Knick and Hanser in press, p. 18). Areas along the edges of the sage-grouse range (e.g., Columbia Basin, Bi-State area) are currently isolated from other sage-grouse populations (Knick and Hanser in press, p. 28).
Connectivity between sage-grouse MZs and the populations within them declined across all three analysis periods examined: 1965–1974, 1980–1989, and 1998–2007. The decline in connectivity was due to the loss of leks and reduced population size (Knick and Hanser in press, p. 29). Historic leks with low connectivity also were lost (Knick and Hanser in press, p. 20), suggesting that current isolation of leks by distance (including habitat fragmentation) will likely result in their future loss (Knick and Hanser in press, p. 28). Small decreases in lek connectivity resulted in large increases in probability of lek abandonment (Knick and Hanser, in press, p. 29). Therefore, maintaining habitat connectivity and sage-grouse population numbers are essential for sage-grouse persistence.
Sagebrush distribution was the most important factor in maintaining connectivity (Knick and Hanser in press, p. 32). This result suggests that any activities that remove or fragment sagebrush habitats will contribute to loss of connectivity and population isolation. This conclusion is consistent with research from both Aldridge
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations (50 CFR part 424) set forth procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. In making this finding, we summarize below information regarding the status and threats to the greater sage-grouse in relation to the five factors provided in section 4(a)(1) of the Act. Under section (4) of the Act, we may determine a species to be endangered or threatened on the basis of any of the following five factors: (A) Present or threatened destruction, modification, or curtailment of habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. Our evaluation of threats is based on information provided in the petition, available in our files, and other sources considered to be the best scientific and commercial information available, including published and unpublished studies and reports.
Differences in ecological conditions within each MZ affect the susceptibility of these areas to the various threats facing sagebrush ecosystems and its potential for restoration. For example,
Several factors are contributing to the destruction, modification, or curtailment of the greater sage-grouse's habitat or range. Several recent studies have demonstrated that sagebrush area is one of the best landscape predictors of greater sage-grouse persistence (Aldridge
Sagebrush is estimated to have covered roughly 120 million ha (296 million ac; Schroeder
Habitat conversion results in loss of habitat available for sage-grouse use. The actual effect of this loss depends on the amount of sagebrush lost, the type of seasonal habitat affected, and the arrangement of habitat lost (large blocks or small patches) (Knick
To estimate the area possibly influenced by these indirect effects, Knick
Soil associations have resulted in disproportionate levels of habitat conversion across different sagebrush communities. For example,
Large losses of sagebrush shrub-steppe habitats due to agricultural conversion have occurred in some areas within the range of the greater sage-grouse. This loss has been especially apparent in the Columbia Basin of the Northwest (MZ VI), the Snake River Plain of Idaho (MZ IV) (Schroeder
Prior to EuroAmerican settlement in the 19th century, Washington had an estimated 42 million ha (103.8 million ac) of shrub-steppe (Connelly
Braun concluded that development of irrigation projects to support agricultural production in areas where soils were sufficient to support agriculture, in some cases conjointly with hydroelectric dam construction, has resulted in additional sage-grouse habitat loss (Braun 1998, p. 142). The reservoirs formed by these projects impacted native shrub-steppe habitat adjacent to the rivers in addition to supporting the irrigation and direct conversion of shrub-steppe lands to agriculture. The projects precipitated conversion of large expanses of upland shrub-steppe habitat in the Columbia Basin for irrigated agriculture (65 FR 51578). The creation of these reservoirs also inundated hundreds of kilometers of riparian habitats used by sage-grouse broods (Braun 1998, p. 144). However, other small and isolated reclamation projects (4,000 to 8,000 ha (10,000 to 20,000 ac)) were responsible for three-fold localized increases in sage-grouse populations (Patterson 1952, pp. 266-274) by providing water in a semiarid environment, which provided additional insect and forb food resources (e.g., Eden Reclamation Project in Wyoming). Benefits of providing water through agricultural activities may now be negated due to the threat of West Nile virus (WNv) (Walker
Five percent of the areas occupied by Great Basin sagebrush have been converted to agriculture, urban or industrial areas (MZs III and IV) (Miller
Aldridge
Sagebrush habitat continues to be converted for both dryland and irrigated crop production (Montana Farm Services Agency (FSA) in litt, 2009; Braun 1998, p. 142; 65 FR 51578, August 24, 2000). The increasing value of wheat and corn crops has driven new conversions in recent years. For example, the acres of sagebrush converted to tilled agriculture in Montana increased annually from 2005 to 2009, with approximately 10,259 ha (25,351 ac) converted, primarily in the eastern two-thirds of the State (MZ I) (Montana FSA in litt, 2009). In addition, in 2008, a single conversion in central Montana totaled between 3,345 and 10,000 ha (10,000 and 30,000 ac) (MZ I) (Hanebury 2008a, pers. comm.). Other large conversions occurred in the same part of Montana in 2008, although these were unquantified (Hanebury 2008b, pers. comm.). We were unable to gather any further information on crop conversions of sagebrush habitats as there are no systematic efforts to collect State or local data on conversion rates in the majority of the greater sage-grouse range (GAO 2007, p. 16).
In addition to crop conversion for traditional crops, recent interest in the development of crops for use as biofuels could potentially impact sage-grouse. For example, the 2008 Farm Bill authorized the Biomass Crop Assistance Program (BCAP), which provides financial incentives to agricultural producers that establish and produce eligible crops for conversion to bioenergy products (U.S. Department of Agriculture (USDA) 2009b, p. 1). Further loss of sagebrush habitats due to BCAP will negatively impact sage-grouse populations. However, currently we have no way of predicting the magnitude of BCAP impacts to sage-grouse (see discussion under Factor D, below).
Although conversion of shrub-steppe habitat to agricultural crops impacts sage-grouse through the loss of sagebrush on a broad scale, some studies report the use of agricultural crops (e.g., alfalfa) by sage-grouse. When alfalfa fields and other croplands are adjacent to extant sagebrush habitat, sage-grouse have been observed feeding in these fields, especially during brood-rearing (Patterson 1952, p. 203; Rogers 1964, p. 53; Wallestad 1971, p. 134; Connelly
Some conversion of cropland to sagebrush has occurred in former sage-grouse habitats through the USDA's voluntary Conservation Reserve Program (CRP) which pays landowners a rental fee to plant permanent vegetation on portions of their lands, taking them out of agricultural production. In Washington State (Columbia Basin, MZ VI), sage-grouse have declined precipitously in the Columbia Basin largely due to conversion of sagebrush habitats to cropland (Schroeder and Vander Haegen, in press, p. 4). Approximately 599,314 ha (1,480,937 ac) of converted farmland had been enrolled in the CRP, almost all of which was historically shrub-steppe (Schroeder and Vander Haegen in press, p. 5). Schroeder and Vander Haegen (in press, p. 20) found that CRP lands that have been out of production long enough to allow re-establishment of sagebrush and was juxtaposed to a relatively intact shrub-steppe landscape was most beneficial to sage-grouse. There appears to be some correlation with sage-grouse use of CRP and a slight increase in population size in north-central Washington (Schroeder and Vander Haegen in press, p. 21). Schroeder and Vander Haegen (in press, p. 21) concluded that the loss of CRP due to expiration of the program or incentives to produce biofuels would likely severely impact populations in the Columbia Basin.
Although estimates of the numbers of acres enrolled rangewide in CRP (and the number of acres soon to expire from CRP) are available, the extent of cropland conversion to habitats beneficial to sage-grouse (i.e., CRP lands planted with native grasses, forbs, and shrubs) is not known for any other area barring the Columbia Basin. Thus, outside this area, we cannot judge the overall impact of CRP land to sage-grouse persistence.
Direct habitat loss and conversion also occurs via numerous other landscape uses, including urbanization, livestock forage production, road building, and oil pads. These activities are described in greater detail below. Although we were unable to obtain an estimate of the total amount of sagebrush habitats that have been lost due to these activities, they have resulted in habitat fragmentation, as well as habitat loss.
Low densities of indigenous peoples have been present for more than 12,000 years in the historical range of sage-grouse. By 1900, less than 1 person per km
The dominant urban areas in the sage-grouse range are located in the Bear River Valley of Utah, the portion of Bonneville Basin southeast of the Great Salt Lake, the Snake River Valley of southern Idaho, and the Columbia River Valley of Washington (Rand McNally Road Atlas 2003; Connelly
Knick
Since 1950, the western U.S. population growth rate has exceeded the national average (Leu and Hanser in press, p. 4). This growth has led to increases in urban, suburban, and rural development. Rural development has increased especially rapidly in recent decades. For example, the amount of uninhabited area in the Great Basin
Recent changes in demographic and economic trends have resulted in greater than 60 percent of the Rocky Mountain West's counties experiencing rural sprawl where rural areas are outpacing urban areas in growth (Theobald 2003, p. 3). In some Colorado counties, up to 50 percent of sage-grouse habitat is under rural subdivision development, and an estimated 3 to 5 percent of all sage-grouse historical habitat in Colorado has already been converted into urban areas (Braun 1998, p. 145). We are unaware of similar estimates for other States within the range of the greater sage-grouse and, therefore, cannot determine the effects of this factor on a rangewide basis. Rural development has increasingly taken the form of low-density (approximately 6 to 25 homes per km
In modeling sage-grouse persistence, Aldridge
Habitat fragmentation is the separation or splitting apart of previously contiguous, functional habitat components of a species. Fragmentation can result from direct habitat losses that leave the remaining habitat in noncontiguous patches, or from alteration of habitat areas that render the altered patches unusable to a species (i.e., functional habitat loss). Functional habitat losses include disturbances that change a habitat's successional state or remove one or more habitat functions; physical barriers that preclude use of otherwise suitable areas; and activities that prevent animals from using suitable habitat patches due to behavioral avoidance.
Sagebrush communities exhibit a high degree of variation in their resistance and resilience to change, beyond natural variation. Resistance (the ability to withstand disturbing forces without changing) and resilience (the ability to recover once altered) generally increase with increasing moisture and decreasing temperatures, and also can be linked to soil characteristics (Connelly
Fragmentation of sagebrush habitats has been cited as a primary cause of the decline of sage-grouse populations because the species requires large expanses of contiguous sagebrush (Patterson 1952, pp. 192-193; Connelly and Braun 1997, p. 4; Braun 1998, p. 140; Johnson and Braun 1999, p. 78; Connelly
Power grids were first constructed in the United States in the late 1800s. The public demand for electricity has grown as human population and industrial activities have expanded (Manville 2002, p. 5), resulting in more than 804,500 km (500,000 mi) of transmission lines (lines carrying greater than 115,000 volts (115 kilovolts (kV)) by 2002 within the United States (Manville 2002, p. 4). A similar estimate is not available for distribution lines (lines carrying less than 69,000volts (69kV)), and we are not aware of data for Canada. Within the SGCA, Knick
Due to the potential spread of invasive species and predators as a result of powerline construction the impact from the powerline is greater than the actual footprint. Knick
In areas where the vegetation is low and the terrain relatively flat, power poles provide an attractive hunting and roosting perch, as well as nesting stratum for many species of raptors and corvids (Steenhof
Leks within 0.4 km (0.25 mi) of new powerlines constructed for coalbed methane development in the Powder River Basin of Wyoming had significantly lower growth rates, as measured by recruitment of new males onto the lek, compared to leks further from these lines, which were presumed to be the result of increased raptor predation (Braun
The presence of a powerline may fragment sage-grouse habitats even if raptors are not present. Braun (1998, p. 146) found that use of otherwise suitable habitat by sage-grouse near powerlines increased as distance from the powerline increased for up to 600 m (660 yd) and, based on that unpublished data, reported that the presence of powerlines may limit sage-grouse use within 1 km (0.6 mi) in otherwise suitable habitat. Similar results were recorded for other grouse species. Pruett
Sage-grouse also may avoid powerlines as a result of the electromagnetic fields (Wisdom
Linear corridors through sagebrush habitats can facilitate the spread of invasive species, such as
Powerlines are common to nearly every type of anthropogenic habitat use, except perhaps some forms of agricultural development (e.g., livestock grazing) and fire. Although we were
Within sage-grouse habitats, 9,510 new communication towers have been constructed within recent years (Connelly
In a comparison of sage-grouse locations in extirpated areas of their range (as determined by museum species and historical observations) and currently occupied habitats, the distance to cellular towers was nearly twice as far from grouse locations in currently occupied habitats than extirpated areas (Wisdom
Fences are used to delineate property boundaries and for livestock management (Braun 1998, p. 145; Connelly
More than 1,000 km (625 mi) of fences were constructed annually in sagebrush habitats from 1996 through 2002, mostly in Montana, Nevada, Oregon, and Wyoming (Connelly
Not all fences present the same mortality risk to sage-grouse. Mortality risk appears to be dependent on a combination of factors including design of fencing, landscape topography, and spatial relationship with seasonal habitats (Christiansen 2009, unpublished data). Although the effects of direct strike mortality on populations are not understood, fences are ubiquitous across the landscape. In many parts of the sage-grouse range (primarily Montana, Nevada, Oregon, Wyoming) fences exceed densities of more than 2 km/km
Fence posts create perching places for raptors and corvids, which may increase their ability to prey on sage-grouse (Braun 1998, p. 145; Oyler-McCance
Interstate highways and major paved roads cover approximately 2,500 km
Impacts from roads may include direct habitat loss, direct mortality, barriers to migration corridors or seasonal habitats, facilitation of predators and spread of invasive vegetative species, and other indirect influences such as noise (Forman and Alexander 1998, pp. 207-231). Sage-grouse mortality resulting from collisions with vehicles does occur (Patterson 1952, p. 81), but mortalities are typically not monitored or recorded. Therefore, we are unable to determine the importance of this factor on sage-grouse populations. Data regarding how roads affect seasonal habitat availability
Roads can provide corridors for predators to move into previously unoccupied areas. For some mammalian species, dispersal along roads has greatly increased their distribution (Forman and Alexander 1998, p. 212; Forman 2000, p. 33). Corvids also use linear features such as primary and secondary roads as travel routes, expanding their movements into previously unused regions (Knight and Kawashima 1993, p. 268; Connelly
The presence of roads increases human access and resulting disturbance effects in remote areas (Forman and Alexander 1998, p. 221; Forman 2000, p. 35; Connelly
The expansion of road networks contributes to exotic plant invasions via introduced road fill, vehicle transport, and road maintenance activities (Forman and Alexander 1998, p. 210; Forman 2000, p. 32; Gelbard and Belnap 2003, p. 426; Knick
Additional indirect effects of roads may result from birds' behavioral avoidance of road areas because of noise, visual disturbance, pollutants, and predators moving along a road. The absence of vegetation in arid and semiarid regions that may buffer these impacts further exacerbates the problem (Suter 1978, p. 6). Male sage-grouse lek attendance was shown to decline within 3 km (1.9 mi) of a methane well or haul road with traffic volume exceeding one vehicle per day (Holloran 2005, p. 40). Male sage-grouse depend on acoustical signals to attract females to leks (Gibson and Bradbury 1985, p. 82; Gratson 1993, p. 692). If noise interferes with mating displays, and thereby female attendance, younger males will not be drawn to the lek and eventually leks will become inactive (Amstrup and Phillips 1977, p. 26; Braun 1986, pp. 229-230).
Dust from roads and exposed roadsides can damage vegetation through interference with photosynthetic activities. The actual amount of potential damage depends on winds, wind direction, the type of surrounding vegetation and topography (Forman and Alexander 1998, p. 217). Chemicals used for road maintenance, particularly in areas with snowy or icy precipitation, can affect the composition of roadside vegetation (Forman and Alexander 1998, p. 219). We were unable to find any data relating these potential effects directly to impacts on sage-grouse population parameters.
In a study on the Pinedale Anticline in Wyoming, sage-grouse hens that bred on leks within 3 km (1.9 mi) of roads associated with oil and gas development traveled twice as far to nest as did hens bred on leks greater than 3 km (1.9 mi) from roads. Nest initiation rates for hens bred on leks close to roads also were lower (65 versus 89 percent) affecting population recruitment (33 versus 44 percent) (Lyon 2000, p. 33; Lyon and Anderson 2003, pp. 489-490). Lyon and Anderson (2003, p. 490) suggested that roads may be the primary impact of oil and gas development to sage-grouse, due to their persistence and continued use even after drilling and production have ceased. Braun
In a study of 804 leks within 100 km (62.5 mi) of Interstate 80 in southern Wyoming and northeastern Utah, Connelly
Aldridge
Railroads presumably have the same potential impacts to sage-grouse as do roads because they create linear corridors within sagebrush habitats. Railways and the cattle they transport were primarily responsible for the initial spread of
Large losses of sagebrush shrub-steppe habitats due to agricultural conversion have occurred range wide, but have been especially significant in the Columbia Basin of Washington (MZ VI), the Snake River Plain of Idaho (MZ IV), and the Great Plains (MZ I). Conversion of sage brush habitats to cropland continues to occur, although quantitative data is available only for Montana. We do not know the current rate of conversion, but most areas suitable for agricultural production were converted many years ago. The current rate of conversion is likely to increase in the future if incentives for crop production for use as biofuels continue to be offered. Urban and exurban development also have direct and indirect negative effects on sage-grouse, including direct and indirect habitat losses, disturbance, and introduction of new predators and invasive plant species. Given current trends in the Rocky Mountain west, we expect urban and exurban development to continue. Infrastructure such as powerlines, roads, communication towers, and fences continue to fragment sage-grouse habitat. Past and current trends lead us to believe this source of fragmentation will increase into the future. Fragmentation of sagebrush habitats through a variety of mechanisms including those listed above has been cited as a primary cause of the decline of sage-grouse populations (Patterson 1952, pp. 192-193; Connelly and Braun 1997, p. 4; Braun 1998, p. 140; Johnson and Braun 1999, p. 78; Connelly
Many of the native vegetative species of the sagebrush-steppe ecosystem are killed by wildfires, and recovery requires many years. As a result of this loss of habitat, fire has been identified as a primary factor associated with greater sage-grouse population declines (Hulet 1983,
In southeastern Idaho, sage-grouse populations were generally declining across the entire study area, but declines were more severe in post-fire years (Connelly
Fire within 54 km (33.6 mi) of a lek is one of two primary factors in predicting lek extirpation (Knick and Hanser in press, p. 26). Small increases in the amount of burned habitat surrounding a lek had a large influence on the probability of lek abandonment (Knick and Hanser, in press, pp. 29-30). Additionally, fire had a negative effect on lek trends in the Snake River Plain (MZ IV) and Southern Great Basin (MZ III) (Johnson
Herbaceous understory vegetation plays a critical role throughout the breeding season as a source of forage and cover for sage-grouse females and chicks. The response of herbaceous understory vegetation to fire varies with differences in species composition, pre-burn site condition, fire intensity, and pre- and post-fire patterns of precipitation. In general, when not considering the synergistic effects of invasive species, any short-term flush of understory grasses and forbs is lost after only a few years and little difference is apparent between burned and unburned sites (Cook
In addition to altering plant community structure, fires can influence invertebrate food sources
The few studies that have suggested fire may be beneficial for greater sage-grouse were primarily conducted in mesic areas used for brood-rearing (Klebenow 1970, p. 399; Pyle and Crawford 1996, p. 323; Gates 1983,
The nature of historical fire patterns in sagebrush communities, particularly in
Fire rotation, or the average amount of time it takes to burn once through a particular landscape, is difficult to quantify in large sagebrush expanses. Because sagebrush is killed by fire, it does not record evidence of prior burns (i.e., fire scars) as do forested systems. As a result, a clear picture of the complex spatial and temporal pattern of historical fire regimes in most sagebrush communities is not available. Widely variable estimates of historical fire rotation have been described in the literature. Depending on the species of sagebrush and other site-specific characteristics, fire return intervals from 10 to well over 300 years have been reported (McArthur 1994, p. 347; Peters and Bunting 1994, p. 33; Miller and Rose 1999, p. 556; Kilpatrick 2000, p. 1; Frost 1998,
The invasion of exotic annual grasses, such as
Evidence exists of a significant relationship between an increase in fire occurrence caused by
Conifer woodlands have expanded into sagebrush ecosystems over the last century (Miller
Between 1980 and 2007, the number of fires and total area burned increased in all MZs across the greater sage-grouse's range except the Snake River Plain (MZ IV) (Miller
From 1980 to 2007, wildfires have burned approximately 8.7 million ha (21.5 million ac) of sagebrush, or approximately 18 percent of the estimated 47.5 million ha (117.4 million ac) of sagebrush habitat occurring within the delineated MZs (Baker, in press, p. 43). Additionally, the trend in total acreage burned since 1980 has primarily increased (Miller
According to one review, range fires destroyed 30 to 40 percent of sage-grouse habitat in southern Idaho (MZ IV) in a 5–year period (1997–2001) (Signe Sather-Blair, BLM,
Baker (in press, p. 20) calculated recent fire rotation by MZ and compared these to estimates of historical fire rotations. Based on this analysis, the researcher suggests that increased fire rotations since 1980 are presumably outside the historic range of variability and far shorter in floristic regions where Wyoming big sagebrush is common (Baker in press, p. 20). This analysis included MZs III, IV, V, and VI, all of which have extensive
In addition to wildfire, land managers are using prescribed fire as well as mechanical and chemical treatments to obtain desired management objectives for a variety of wildlife species and domestic ungulates in sagebrush habitats throughout the range of the greater sage-grouse. While the efficacy of treatments in sagebrush habitats to enhance sage-grouse populations is questionable (Peterson 1970, p. 154; Swensen
Knick
Sagebrush recovery rates are highly variable, and precise estimates are often
A variety of techniques have been employed to restore sagebrush communities following a fire event (Cadwell
The main purpose of the Burned Area Emergency Stabilization and Rehabilitation program (BLM 2007b, pp. 1-2), designed to rehabilitate areas following fire, is to stabilize soils and maintain site productivity rather than to regain site suitability for wildlife (Pyke, in press, p. 24). Consequently, in areas that experience active post-fire restoration efforts, an emphasis is often placed on introduced grasses that establish quickly. Only recently has a modest increase in the use of native species for burned area rehabilitation been reported (Richards
The loss of habitat due to wildland fire is anticipated to increase due to the intensifying synergistic interactions among fire, people, invasive species, and climate change (Miller
While multiple factors can influence sagebrush persistence, fire is the primary cause of recent large-scale losses of habitat within the Great Basin, and this stressor is anticipated to intensify. In addition to loss of habitat and its influence on greater sage-grouse population persistence, fragmentation and isolation of populations presents a higher probability of extirpation in disjunct areas (Knick and Hanser, in press, p. 20; Wisdom
Fire is one of the primary factors linked to population declines of greater sage-grouse because of long-term loss of sagebrush and conversion to monocultures of exotic grasses (Connelly and Braun 1997, p. 7; Johnson
An analysis of previously extirpated sage-grouse habitats has shown that the extent and abundance of sagebrush habitats, proximity to burned habitat, and degree of connectivity among sage-grouse groups strongly affects persistence (Aldridge
For the purposes of our analysis in this section, we consider invasive plants (invasives) to be any nonnative plant that negatively impacts sage-grouse habitat, including annual grasses and other noxious weeds. However, in the literature that we reviewed, the terms noxious weeds and invasives were not consistently defined or applied. Consequently, both terms are used in our discussion to reflect the original use in the sources we cite. In the source material, it was often unclear whether discussions about noxious weeds included invasive annual grasses (e.g.,
Invasives alter plant community structure and composition, productivity, nutrient cycling, and hydrology (Vitousek 1990, p. 7) and may cause declines in native plant populations through competitive exclusion and niche displacement, among other mechanisms (Mooney and Cleland 2001, p. 5446). Invasive plants reduce and, in cases where monocultures occur, eliminate vegetation that sage-grouse use for food and cover. Invasives do not provide quality sage-grouse habitat. Sage-grouse depend on a variety of native forbs and the insects associated with them for chick survival, and sagebrush, which is used exclusively throughout the winter for food and cover. Invasives impact the entire range of sage-grouse, although not all given species are distributed across the entire range. Leu
Along with replacing or removing vegetation essential to sage-grouse, invasives fragment existing sage-grouse habitat. They can create long-term changes in ecosystem processes, such as fire-cycles (see discussion under Fire above) and other disturbance regimes that persist even after an invasive plant is removed (Zouhar
Nonnative annual grasses (e.g.,
Quantifying the total amount of sage-grouse habitat impacted by invasives is problematic due to differing sampling methodologies, incomplete sampling, inconsistencies in species sampled, and varying interpretations of what constitutes an infestation (Miller
The Landscape Fire and Resource Management Planning Tools Project (LANDFIRE) has a rangewide dataset documenting annual grass distribution. Based on 1999–2002 imagery, at least 885,990 ha (2.2 million ac) of annual grasses occur within the current range of sage-grouse (LANDFIRE 2007). Satellite data only map annual grass monocultures, and not areas where they occur in lower densities or even dominate the sagebrush understory (which is mapped as sagebrush). Therefore, the LANDFIRE dataset is a gross underestimate of the total acres of infestation. However, this dataset provides a rangewide comparison of annual grass monocultures and identifies the large extent of these monocultures in both the western and eastern part of the sage-grouse's range.
Approximately 80 percent of land in the Great Basin Ecoregion (MZs III, IV, and V) is susceptible to displacement by
Noxious weeds spread about 931 ha (2,300 ac) per day on BLM land and 1,862 ha (4,600 ac) per day on all public land in the West (BLM 1996, p. 1), or increase about 8 to 20 percent annually (
Based on data collected in the western half of the range, Bradley
LANDFIRE also has a rangewide dataset documenting other exotic grasses and forbs, including perennial grasses and annual, perennial, and biennial forbs. Like annual grasses, other invasive plants are grossly underestimated in the LANDFIRE dataset because the dataset only includes monocultures of these species. Based on 1999–2002 imagery, at least 1.3 million ha (3.3 million ac) of other exotic plants occur within the current range of sage-grouse (LANDFIRE 2007). Aside from LANDFIRE, the only other information documenting the specific distribution of invasives within the sage-grouse's range is at a presence–absence scale at the county level. DiTomaso (2000, p. 257) estimated that western rangelands are infested with 2,900,000 ha (7,166,027 ac) of
Invasives that are not annual grasses impact the entire range of sage-grouse, although not all given species are distributed across the entire range. Leu
Many efforts are ongoing to restore or rehabilitate sage-grouse habitat affected by invasive species. Common rehabilitation techniques include first reducing the density of invasives using herbicides, defoliation via grazing, pathogenic bacteria and other forms of biocontrol, or prescribed fire (Tu
Several components of the restoration process are being investigated with varying success (Pyke, in press, p. 25). Some techniques show promise, such as use of the herbicide Imazapic to control
Treatment success also depends on factors which are not controllable, such as precipitation received at the treatment site (Pyke, in press, p. 30). For example, only 3.3 to 33.6 percent of recent vegetation treatments conducted by the BLM in annual grassland monocultures were reported as successful (Carlson 2008b, pers. comm.). Areas with established annual grasses that receive less than 22.9 cm (9 in.) of annual precipitation are less likely to benefit from restoration (Connelly
A variety of regulatory mechanisms and nonregulatory measures to control invasive plants exist. However, the extent to which these mechanisms effectively ameliorate the current rate of invasive expansion is unclear. If noxious weeds are spreading at a rate of 931 ha (2,300 ac) per day on BLM lands (BLM 1996, p. 1), this amounts to 339,815 ha (839,500 ac) per year, which includes both suitable and nonsuitable habitat for sage-grouse. It is unclear whether this estimate is limited to noxious weeds or if it includes other invasives (e.g.,
The number of acres treated annually (86,632 ha; 214,072 ac) is not keeping pace with the rate of spread (339,815 ha; 839,500 ac) especially when considering the inability to treat the problem. We acknowledge that the rate of spread on BLM lands also includes areas that are not sage-grouse habitat. However, the rate of spread may not have included
The National Invasive Species Council (2008, p. 8) acknowledges that there has been a significant increase in activity and awareness, but that much remains to be done to prevent and mitigate the problems caused by invasive species. As an example, the State of Montana has made much progress through partnerships in reducing noxious weeds in the State from 3.2 million ha (8 million ac) in 2000 to 3.1 million ha (7.6 million ac) in 2008 (Montana Weed Control Association 2008). However, the Montana Noxious Weed Summit Advisory Council Weed Management Task Force (2008, p. III) estimates that to slow weed spread and reduce current infestations by 5 percent annually, they require 2.6 times the current level of funding from a variety of private, local, State, and Federal sources (or $55.8 million versus $21.2 million). In addition to funding, other factors that potentially limit ability to control invasives include the amount of available native seed sources, the time it takes to restore sagebrush to an area once it is removed from a site, and the existence of treatments that are known to be effective in the long-term. Monitoring is limited in many cases and, where it occurs, monitoring typically does not document the population response of sage-grouse to these treatments.
Invasives are a serious rangewide threat, and one of the highest risk factors for sage-grouse based on the plants' ability to out-compete sagebrush, the inability to effectively control them once they become established, and the synergistic interaction between them and other risk factors on the landscape (e.g., wildfire, infrastructure construction). Invasives reduce and eliminate vegetation that is essential for sage-grouse to use as food and cover. Their presence on the landscape has removed and fragmented sage-grouse habitat. Because invasives are widespread, have the ability to spread rapidly, occur near areas susceptible to invasion, and are difficult to control, we anticipate that invasives will continue to replace and reduce the quality of sage-grouse habitat across the range in the foreseeable future. There have been many studies addressing effective invasive control methods, as well as conservation actions to control invasives, with varied success. While some efforts appear successful at smaller scales, prevention (e.g., early detection and fire prevention) appears to be the only known effective tool to preclude or minimize large-scale habitat loss from invasive species in the future.
Pinyon-juniper woodlands are a native habitat type dominated by pinyon pine (
Pinyon-juniper woodlands are often associated with sagebrush communities and currently occupy at least 18 million ha (44.6 million ac) of the Intermountain West within the sage-grouse's range (Crawford
Connelly
Annual encroachment rates that were reported in five studies ranged from 0.3 to 31 trees per hectare (0.7 to 77 trees per acre) (Sankey and Germino 2008, p. 413). For the three studies that measured the percent increase in juniper cover per year, cover increased between 0.4 and 4.5 percent annually (Sankey and Germino 2008, p. 413). Sankey and Germino (2008, p. 413) compared juniper encroachment rates from previous research to their study. Their estimate that juniper cover increased 0.7 to 1.5 percent annually was based on a 22 to 30 percent increase in cover between 1985 and 2005 at their southeastern Idaho study site (Sankey and Germino 2008, pp. 412-413).
Pinyon-juniper expansion into sagebrush habitats, with subsequent replacement of sagebrush communities, has been well documented (Miller
While pinyon-juniper expansion appears less problematic in the eastern portion of the range (MZs I, II and VII) and silver sagebrush areas (primarily MZ I), woodland encroachment is a threat mentioned in Wyoming, Montana, and Colorado State sage-grouse conservation plans, indicating that this is of some concern in these States as well (Stiver
Recently, many conservation actions have addressed this threat using a variety of techniques (e.g., mechanical, herbicide, cutting, burning) to remove conifers in sage-grouse habitat. The effectiveness of these treatments varies with the technique used and proximity of the site to invasive plant infestations, among other factors. We are not aware of any study documenting a direct correlation between these treatments and increased greater sage-grouse productivity; however, we infer some level of positive response based on Commons
Furthermore, while many acres have been treated since 2004, treatments are not likely keeping pace with the current rate of pinyon-juniper encroachment, at least in parts of the range. For example, while Oregon has treated approximately 8,094 ha (20,000 ac) of juniper to restore native sagebrush habitat between 2003 and early 2008 (about 1,619 ha or 4,000 ac per year; ODFW 2008, p. 3), LANDFIRE data show at least 106,882 ha (264,110 ac) of juniper occur within 4.8 km (3 mi) of Oregon leks. This distance (4.8 km; 3 mi) reflects the upper estimate of a typical pinyon seed dispersal event, although seeds may be dispersed shorter distances and up to at least 10 km (6.2 mi) (Chambers
Again, LANDFIRE data provides a gross underestimate of pinyon-juniper since it misses single, large trees. This underestimate suggests that it will take longer than 60 years to fully address the threat of juniper encroachment in Oregon, if conservation actions continue to occur at the current rate. Furthermore, not all treatments are effective. Of the 38,780 ha (95,826 ac) treated by BLM in Fiscal Year (FY) 2006 and FY 2007, only 21,598 ha (53,369 ac), or 55.7 percent were considered to be effective by the BLM (Carlson 2008b, pers. comm.). Again, the measure of effectiveness typically refers to whether
Invasives plants negatively impact sage-grouse primarily by reducing or eliminating native vegetation that sage-grouse require for food and cover, resulting in habitat loss and fragmentation. A variety of nonnative annuals and perennials (e.g., Bromus tectorum, Euphorbia esula) and native conifers (e.g., pinyon pine, juniper species) are invasive to sagebrush ecosystems. Nonnative invasives, including annual grasses and other noxious weeds, continue to expand their range, facilitated by ground disturbances such as wildfire, grazing, and infrastructure. Pinyon and juniper and some other native conifers are expanding and infilling their current range mainly due to decreased fire return intervals, livestock grazing, and increases in global carbon dioxide concentrations associated with climate change, among other factors.
Collectively, invasives plants impact the entire range of sage-grouse, although they are most problematic in the Intermountain West and Great Basin (MZs III, IV, V, and VI). A large portion of the Great Basin is at risk of
A variety of restoration and rehabilitation techniques are used to treat invasive plants, but they can be costly and are mostly unproven and experimental. The success of treatments, particularly for annual grassland restoration, depends on uncontrollable factors (e.g., precipitation). While some efforts appear successful at smaller scales, prevention appears to be the only known effective tool to preclude large-scale habitat loss from invasive annuals and perennials in the future. Pinyon-juniper treatments, particularly when done in the early stages of encroachment when sagebrush and forb understory is still intact, have the potential to provide an immediate benefit to sage-grouse. However, studies have not yet documented a correlation between pinyon-juniper treatments and increased greater sage-grouse productivity.
Native herbivores, such as pronghorn antelope (
Excessive grazing by domestic livestock during the late 1800s and early 1900s, along with severe drought, significantly impacted sagebrush ecosystems (Knick
Although little direct experimental evidence links grazing practices to population levels of greater sage-grouse (Braun 1987, p. 137; Connelly and Braun 1997, p. 231), the impacts of livestock grazing on sage-grouse habitat and on some aspects of the life cycle of the species have been studied. Sage-grouse need significant grass and shrub cover for protection from predators, particularly during nesting season, and females will preferentially choose nesting sites based on these qualities (Hagen
Several authors have noted that grazing by livestock could reduce the suitability of breeding and brood-rearing habitat, negatively affecting sage-grouse populations (Braun 1987, p. 137; Dobkin 1995, p. 18; Connelly and Braun 1997, p. 231; Beck and Mitchell 2000, pp. 998-1000). Exclosure studies have demonstrated that domestic livestock grazing reduces water infiltration rates and cover of herbaceous plants and litter, as well as compacting soils and increasing soil erosion (Braun 1998, p. 147; Dobkin
Livestock also may compete directly with sage-grouse for rangeland resources. Cattle are grazers, feeding mostly on grasses, but they will make seasonal use of forbs and shrub species like sagebrush (Vallentine 1990, p. 226). Domestic sheep are intermediate feeders making high use of forbs, but also using a large volume of grass and shrub species like sagebrush (Vallentine 1990, pp. 240-241). Sheep consume rangeland forbs in occupied sage-grouse habitat (Pederson
Other effects of direct competition between livestock and sage-grouse depend on condition of the habitat and the grazing practices. Thus, the effects vary across the range of the greater sage-grouse. For example, Aldridge and Brigham (2003, p. 30) suggest that poor livestock management in mesic sites, which are considered limited habitats for sage-grouse in Alberta (Aldridge and Brigham 2002, p. 441), results in a reduction of forbs and grasses available to sage-grouse chicks, thereby affecting chick survival.
Other consequences of grazing include several related to livestock trampling of grouse and habitat. Although the effect of trampling at a population level is unknown, outright nest destruction has been documented and the presence of livestock can cause sage-grouse to abandon their nests (Rasmussen and Griner 1938, p. 863; Patterson 1952, p. 111; Call and Maser 1985, p. 17; Holloran and Anderson 2003, p. 309; Coates 2007, p.28). Coates (2007, p. 28) documented nest abandonment following partial nest depredation by a cow. In general all recorded encounters between livestock and grouse nests resulted in hens flushing from nests, which could expose the eggs to predation; there is strong evidence that visual predators like ravens use hen movements to locate sage-grouse nests (Coates 2007, p.33). Livestock also may trample sagebrush seedlings, thereby removing a source of future sage-grouse food and cover (Connelly
Some livestock grazing effects may have positive consequences for sage-grouse. Evans (1986, p. 67) found that sage-grouse used grazed meadows significantly more during late summer than ungrazed meadows because grazing had stimulated the regrowth of forbs. Klebenow (1981, p. 121) noted that sage-grouse sought out and used openings in meadows created by cattle grazing in northern Nevada. Also, both sheep and goats have been used to control invasive weeds (Mosley 1996 as cited in Connelly
Sagebrush plant communities are not adapted to domestic grazing disturbance. Grazing changed the functioning of systems into less resilient, and in some cases, altered communities (Knick
Extensive rangeland treatment has been conducted by federal agencies and private landowners to improve conditions for livestock in the sagebrush-steppe region (Connelly
Greater sage-grouse response to herbicide treatments depends on the extent to which forbs and sagebrush are killed. Chemical control of sagebrush has resulted in declines of sage-grouse breeding populations through the loss of live sagebrush cover (Connelly
Mechanical treatments are designed to either remove the aboveground portion of the sagebrush plant (mowing, roller chopping, and roto-beating), or to uproot the plant from the soil (grubbing, bulldozing, anchor chaining, cabling, railing, raking, and plowing; Connelly
The current extent to which mechanical, chemical, and prescribed fire methods are used to remove or control sagebrush is not known, particularly with regard to private lands. However, BLM has stated that with rare exceptions, they no longer are involved
Historically, the elimination of sagebrush followed with rangeland seedings was encouraged to improve forage for livestock grazing operations (Blaisdell 1949, p. 519). Large expanses of sagebrush removed via chemical and mechanical methods have been reseeded with nonnative grasses, such as crested wheatgrass (
Water developments for the benefit of livestock and wild ungulates on public lands are common (Connelly
Another indirect negative impact to sage-grouse from livestock grazing occurs due to the placement of thousands of miles of fences for livestock management purposes (see discussion above under Infrastructure). Fences cause direct mortality through collision and indirect mortality through the creation of predator perch sites, the potential creation of predator corridors along fences (particularly if a road is maintained next to the fence), incursion of exotic species along the fencing corridor, and habitat fragmentation (Call and Maser 1985, p. 22; Braun 1998, p. 145; Connelly
The impacts of livestock operations on sage-grouse depend upon stocking levels, season of use, and utilization levels. Cattle and sheep Animal Unit Months (AUMs) (the amount of forage required to feed one cow with calf, one horse, five sheep, or five goats for 1 month) on all Federal land have declined since the early 1900s (Laycock
Free-roaming horses and burros have been a component of sagebrush and other arid communities since they were brought to North America at the end of the 16th century (Wagner 1983, p. 116; Beever 2003, p. 887). About 31,000 wild horses occur in 10 western States (including 2 states outside the range of the greater sage-grouse), with herd sizes being largest in Nevada, Wyoming, and Oregon, which are the States with the most extensive sagebrush cover (Connelly
We are unaware of any studies that directly address the impact of wild horses or burros on sagebrush and sage-grouse. However, some authors have suggested that wild horses could negatively impact important meadow and spring brood-rearing habitats used by sage-grouse (Crawford
Currently, free-roaming equids consume an estimated 315,000 to 433,000 AUMs as compared to over 7 million AUMs for domestic livestock within the range of greater sage-grouse (Beever and Aldridge, in press, p. 21). Cattle typically outnumber horses by a large degree in areas where both occur; however, locally ratios of 2:1 (horse:cow) have been reported (Wagner 1983, p.126). The local effects of ungulate grazing depend on a host of abiotic and biotic factors (e.g., elevation, season, soil composition, plant productivity, and composition). Additional significant biological and behavioral differences influence the impact of horses as compared to cattle grazing on habitat (Beever 2003, pp. 888-890). For example, due to physiological differences, a horse must forage longer and consumes 20 to 65 percent more forage than would a cow of equivalent body mass (Wagner 1983, p. 121; Menard
Native herbivores, such as elk (
We are unaware of studies evaluating the effects of native ungulate herbivory on sage-grouse and sage-grouse habitat. However, concentrated native ungulate herbivory may impact vegetation in sage-grouse habitat on a localized scale. Native ungulate winter browsing can have substantial, localized impacts on sagebrush vigor, resulting in decreased shrub cover or sagebrush mortality (Wambolt 1996, p. 502; Wambolt and Hoffman 2004, p. 195). Additionally, despite decreased habitat availability, elk and mule deer populations are currently higher than pre-European estimates (Wasley 2004, p. 3; Young and Sparks 1985, pp. 67-68). As a result, some States started small-scale supplemental feeding programs for deer and elk. In those localized areas, vegetation is heavily utilized from the concentration of animals (Doman and Rasmussen 1944, p. 319; Smith 2001, pp. 179-181). Unlike domestic ungulates, wild ungulates are not confined to the same area, at the same time each year. Therefore, the impacts from wild ungulates are spread more diffusely across the landscape, resulting in minimal long-term impacts to the vegetation community.
Livestock management and domestic grazing can seriously degrade sage-grouse habitat. Grazing can adversely impact nesting and brood-rearing habitat by decreasing vegetation concealment from predators. Grazing also has been shown to compact soils, decrease herbaceous abundance, increase erosion, and increase the probability of invasion of exotic plant species. Once plant communities have an invasive annual grass understory dominance, successful restoration or rehabilitation techniques are largely unproven and experimental (Pyke, in press, p. 25). Massive systems of fencing constructed to manage domestic livestock cause direct mortality to sage-grouse in addition to degrading and fragmenting habitats. Livestock management also can involve water developments that can degrade important brood-rearing habitat and or facilitate the spread of WNv. Additionally, some research suggests there may be direct competition between sage-grouse and livestock for plant resources. However, although there are obvious negative impacts, some research suggests that under very specific conditions grazing can benefit sage-grouse.
Similar to domestic grazing, wild horses and burros have the potential to negatively affect sage-grouse habitats in areas where they occur by decreasing grass cover, fragmenting shrub canopies, altering soil characteristics, decreasing plant diversity, and increasing the abundance of invasive
Native ungulates have coexisted with sage-grouse in sagebrush ecosystems. Elk and mule deer browse sagebrush during the winter and can cause mortality to small patches of sagebrush from heavy winter use. Pronghorn antelope, largely overlapping with sage-grouse habitat year around, consume grasses and forbs during the summer and browse on sagebrush in the winter. We are not aware of research analyzing impacts from these native ungulates on sage-grouse or sage-grouse habitat.
Currently there is little direct evidence linking grazing practices to population levels of greater sage-grouse. However, testing for impacts of grazing at landscape scales important to sage-grouse is confounded by the fact that almost all sage-grouse habitat has at one time been grazed and thus no non-grazed, baseline areas currently exist with which to compare (Knick
Greater sage-grouse populations are negatively affected by energy development activities (primarily oil, gas, and coal-bed methane), especially those that degrade important sagebrush habitat, even when mitigative measures are implemented (Braun 1998, p. 144; Lyon 2000, pp. 25-28; Holloran 2005, pp. 56-57; Naugle
Nonrenewable fossil fuel energy development (e.g., petroleum products, coal) has been occurring in sage-grouse habitats since the late 1800s (Connelly
Global recession starting in 2008 resulted in decreased energy demand and subsequently slowed rate of energy development (Energy Information Administration (EIA) 2009b, p. 2). However, the production of fossil fuels is predicted to regain and surpass the early 2008 levels starting in 2010 (EIA 2009b, p. 109). Forecasts to the year 2030 predict fossil fuels to continue to provide for the United States' energy needs while not necessarily in conventional forms or from present extraction techniques (EIA 2009b, pp. 2-4, 109). Recent concerns about curbing greenhouse gas emissions associated with fossil fuel use are being addressed through government policy, legislation, and advanced technologies and are likely to effect a transition in fuel form (EIA 2009b, pp. 2-3, 78).
The decline in use of conventional fossil fuels for power generation in the future is expected to be supplemented with biomass, unconventional oil and gas, and renewable sources—all of which are existing or potentially available in current sage-grouse habitats (U.S. Department of Energy (DOE) 2006, p. 3; National Petroleum Council 2007, p. 6; BLM 2005a, p. 2-4; National Renewable Energy Laboratory (NREL) 2008a, entire; Idaho National Engineering and Environmental Laboratory 2003, entire; EIA 2009b, pp. 2-4). For example, oil shale and tar sands are unconventional fossil fuel liquids predicted for increased development in the sage-grouse range. Shale sources providing 2 million barrels per day in 2007 are expected to contribute 5.6–6.1 million barrels by 2030 (EIA 2009b, p. 30). Extraction of this resource involves removal of habitat and disturbance similar to oil and gas development (see discussion below). National reserves of oil shale lie primarily in the Uinta–Piceance area of Colorado and Utah (MZs II, III, and VII), and the Green River and Washakie areas of southwestern Wyoming (MZ II). These 1.4 million ha (3.5 million ac) of Federal lands contain an estimated 1.23 trillion barrels of oil—more than 50 times the United States' proven conventional oil reserves (BLM 2008a, p. 2).
Available EPCA inventories detail energy resources in 11 geological basins (DOI
Oil and gas development has occurred in the past, with historical well locations concentrated in MZs I, II, III, and VII of Wyoming, eastern Montana, western Colorado, and eastern Utah (IHS Incorporated 2006). Currently, oil, conventional gas, or coal-bed methane development occur across the eastern component of the SGCA. Four geological basins are most affected by a concentration of development—Powder River (MZ I), Williston (MZ I), Southwestern Wyoming (MZ II), and the Uinta–Piceance (MZs II, III, VII) coinciding with the highest proportion of high-density areas of sage-grouse, the greatest number of leks, and the highest male sage-grouse attendance at leks compared with any other area in the eastern part of the range (Doherty
Extensive development and operations are occurring in sage-grouse habitats where the number of producing wells has tripled in the past 30 years (Naugle
The Great Plains MZ (MZ I) contains all or portions of the 20.9-million-ha (51.7-million-ac) Powder River and Williston geological basins identified as significant oil and gas resources. The resource areas include 7.2 million ha (18.2 million ac) of sagebrush habitats. Oil and gas infrastructure and planned development occupies less than 1 percent of the land area in MZ I; however, the ecological effect is greater than 20 percent of the sagebrush habitat, based on applying a buffer zone to estimate the potential the distance of sage-grouse response to infrastructure (Lyon and Anderson 2003, p. 489; Knick
In 2002, the BLM in Wyoming proposed development of 39,367 coal-bed methane wells and 3,200 conventional oil or gas wells in the Powder River Basin in addition to an existing 12,024 coal-bed methane wells drilled or permitted (BLM 2002, pp. 2-3). Wells would be developed over a 10–year period with production lasting until 2019 (BLM 2002, p. 3). The BLM estimated 82,073 ha (202,808 ac) of surface disturbance from all activities such as well pads, pipelines, roads, compressor stations, and water handling facilities over a 3.2-million-ha (8-million-ac) project area (BLM 2002, p. 2). Roads and water handling facilities were expected to be long-term disturbances encompassing approximately 38,501 ha (95,140 ac) (BLM 2002, p. 3). Reclamation of well sites was expected to be complete by 2022 (BLM 2002, p. 3). It is not clear if this 2022 date takes into consideration the length of time necessary to achieve suitable habitat conditions for sage-grouse or if restoration of sage-grouse habitat is possible.
Between 1997 and 2007, approximately 35,000 producing wells were in place on Federal, State, and private holdings in the Powder River Basin area (Naugle
The Powder River Basin serves as a link to peripheral sage-grouse populations in eastern Wyoming and western South Dakota and between the Wyoming basin and central Montana. This connectivity is expected to be lost in the near future because of the intensity of development in the region. Sage-grouse populations have declined in the Powder River Basin by 79 percent since the development of coal-bed methane resources (Emmerich 2009, pers. comm.). In the Powder River Basin between 2001 and 2005, sage-grouse lek-count indices declined by 82 percent inside gas fields compared to 12 percent outside development (Walker
Energy development in the Powder River Basin is predicted to continue to actively reduce sage-grouse populations and sagebrush habitats over the next 20 years based on the length of development and production projects described in existing project and management plans. The BLM concluded that sage-grouse habitats would not be restored to pre-disturbance conditions for an extended time (BLM 2003, p. 4-268). Sagebrush restoration after development is difficult to achieve, and successful restoration is not assured as described above (Habitat Description and Characteristics).
The 9.6-million-ha (23.9-million-ac) Williston Basin underlies the northeastern corner of the current sage-grouse range in Montana, North and South Dakota. It is another energy resource area experiencing concentrated oil and gas development in MZ I. Oil production has occurred in the Williston Basin for at least 80 years with oil production peaking in the 1980s (Advanced Resources International 2006, p. 3-3). Advances in technology including directional drilling and coal-bed methane technology have boosted development of oil and gas in the basin (Advanced Resources International 2006, p. 3.2; Zander 2008, p. 1). Large, developed fields are concentrated in the Bowdoin Dome area of north-central Montana and the 193-km (120-mi) long Cedar Creek Anticline area of southeastern Montana, southwestern North Dakota, and northwestern South Dakota. Extensive energy development in the Cedar Creek Anticline area could be isolating the very small North Dakota population from sage-grouse populations in central Montana and the northern Powder River Basin.
One hundred and thirty-six wells were put into production in 2008–2009 in major oil and gas fields of the Williston Basin north of the Missouri River in the range of the Northern Montana sage-grouse population (Montana Department of Natural Resources 2009, entire) including the Bowdoin Dome area. The Bowdoin Dome area is populated by more than 1,500 gas wells with associated infrastructure, and an additional 1,200 new or replacement wells were approved in the remaining occupied active sage-grouse habitat (BLM 2008c, pp. 1, 3-127 to 3-129). Active drilling operations are expected to occur over 10–15 years, and gas production is expected to extend the project life 30–50 additional years (BLM 2008c, p. 1). The BLM's project description does not take into consideration the time period necessary to restore native sagebrush communities to suitability for sage-grouse. Energy extraction, ranching, and tillage agriculture coincide in this area of the State described by Leu and Hanser (in press, p. 44) as experiencing high-intensity human activity that is consistent with lek loss and population decline (Wisdom
Southwestern and central Wyoming and northwestern Colorado in MZ II has been considered a stronghold for sage-grouse with some of the highest estimated densities of males anywhere in the remaining range of the species (Connelly
Oil, gas, and coal-bed methane development is occurring across MZ II, and development is concentrated in some areas. Intensive development and production is occurring in the Greater Green River area in southwestern Wyoming and northern Colorado and northeastern Utah. The BLM published a ROD in 2000 for the Pinedale Anticline Project Area in southwestern Wyoming (BLM 2000, entire). The project description included up to 900 drill pads, including dry holes, over a 10- to 15–year development period (BLM 2008d, p. 4-4). By the end of 2005, approximately 457 wells on 322 well pads were under production (BLM 2008d, p. 6). In 2008, the BLM amended the project to accommodate an accelerated rate of development exceeding that in the 2002 project description (BLM 2008d, p. 4). Approximately 250 new well pads are proposed in addition to pipelines and other facilities (BLM 2008d, p. 36). Total initial direct disturbance acres for the entire Pinedale project are approximately 10,400 ha (25,800 ac) with more than 7,200 ha (18,000 ac) in sagebrush land cover type (BLM 2008d, p. 4-52).
The Jonah Gas Infill Project also is underway in the Pinedale Anticline area of the Southwest Wyoming Basin that expands on the Jonah Project started in 2000. In 2006, the BLM issued a ROD and EIS to extend the existing project to an additional 3,100 wells and up to 6,556 ha (16,200 ac) of new surface disturbance (BLM 2006, p. 2-4). In addition, at least 64 well pads would be situated per 259 ha (640 ac), and up to 761 km (473 mi) of pipeline and roads, 56 ha (140 ac) of additional disturbance for ancillary facilities (p. 2-5) also would occur. The project life of 76 years includes 13 years of development and 63 years of production (BLM 2006, p. 2-15). The project description requires reclamation of disturbed sites and establishment of stabilizing vegetation by 1 year post-reclamation (BLM 2006, p. 2-24) and standard lease stipulations to protect sage-grouse. This project is located in high-density sage-grouse habitat, but it is not clear from the project description if suitable sage-grouse habitat is the reclamation goal. Therefore, sagebrush habitats, and the associated sage-grouse are likely to be lost.
Knick
In the Greater Green River Basin area, yearling male sage-grouse reared near gas field infrastructure had lower survival rates and were less likely to establish breeding territories than males with less exposure to energy development; yearling female sage-grouse avoided nesting within 950 m (0.6 mi) of natural gas infrastructure (Holloran
The Greater Green River area of southwest Wyoming and the Uintah–Piceance basin (discussed below) also are, in addition to oil and gas, important reserves of oil shale and tar sands that are expected to supply more of the nation's resource needs in the future (EIA 2009b, p. 30). The Uintah–Piceance geologic basin includes the Colorado Plateau (MZ VII) and overlaps into the southern edge of the Wyoming Basin (MZ II). Sage-grouse in this part of the range are reduced to four small, isolated populations, a likely consequence of urban and agricultural development (Knick
Based on applying a 3 km (1.9 mi) buffer to construction areas, Knick
Using GIS analysis, we calculated that 70 percent of the sage-grouse breeding habitat is potentially impacted by oil and gas development in the Powder River Basin (Service 2008b). The 70 percent figure was derived from well point data supplied by the BLM, buffered by 3.2 km (2 mi), and intersecting these areas with known lek locations buffered to 6.4 km (4 mi). The 70 percent figure is conservative because the most comprehensive well point data set available was 2 years old and did not reflect the rapid development that occurred in 2008. Breeding habitat is defined as a 6.4-km (4-mi) radius around known lek points and includes the range of the average distances between nests and nearest lek (Autenrieth 1981, p. 18; Wakkinen
The effects of oil and gas development, as described in detail later in this section, are likely to continue for decades even with the current protective or mitigative measures in place. Based on a review of project EISs, Connelly
The BLM is the primary Federal agency managing the United States' energy resources and has the legal authority to regulate and condition oil and gas leases and permits. Although the restrictive stipulations that BLM applies to permits and leases are variable, a 0.4-km (0.25-mi) radius around sage-grouse leks is generally restricted to no surface occupancy (NSO) during the breeding season, and noise and development activities are often limited during the breeding season within a 0.8- to 3.2-km (0.5 to 2-mi) radius of sage-grouse leks. As stated above, the BLM's NSO buffer stipulation is ineffective in protecting sage-grouse (Walker
In some cases, localized areas are experiencing higher levels of effects. Seventy percent of the sage-grouse breeding habitat is within 3 km (2 mi) of development in the Powder River Basin of northeastern Wyoming and southeastern Montana (Service 2008b), where Walker
Energy development impacts sage-grouse and sagebrush habitats through direct habitat loss from well pad, access construction, seismic surveys, roads, powerlines, and pipeline corridors; indirectly from noise, gaseous emissions, changes in water availability and quality, and human presence; and the interaction and intensity of effects could cumulatively or individually lead to fragmentation (Suter 1978, pp. 6-13; Aldridge 1998, p. 12; Braun 1998, pp. 144-148; Aldridge and Brigham 2003, p. 31; Knick
The development of oil and gas resources requires surveys for economically recoverable reserves, construction of well pads and access roads, subsequent drilling and extraction, and transport of oil and gas, typically through pipelines. Ancillary facilities can include compressor stations, pumping stations, electrical generators, and powerlines (Connelly
Well densities and spacing are typically designed to maximize recovery of the resource and are administered by State oil and gas agencies and the BLM, the Federal agency charged with administering the nation's Federal mineral estate (Connelly
Direct habitat loss from the human footprint contributes to decreased population numbers and distribution of the greater sage-grouse (Knick
The ecological footprint is the extended effect of the infrastructure or activity beyond its physical footprint and determined by a physical or behavioral response of the sage-grouse. The physical footprint of oil and gas infrastructure including pipelines is estimated to be 5 million ha (1.2 million ac) and less than 1 percent of the SGCA (Knick
Roads associated with oil and gas development were suggested to be the primary impact to greater sage-grouse due to their persistence and continued use even after drilling and production ceased (Lyon and Anderson 2003, p. 489). Declines in male lek attendance were reported within 3 km (1.9 mi) of a well or haul road with a traffic volume exceeding one vehicle per day (Holloran 2005, p. 40; Walker
Habitat fragmentation resulting from oil and gas development infrastructure, including access roads, may have effects on sage-grouse greater than the associated direct habitat losses. The Powder River Basin infrastructure footprint is relatively small (typically 6-8 ha per 2.6 km
Noise can drive away wildlife, cause physiological stress, and interfere with auditory cues and intraspecific communication. Aldridge and Brigham (2003, p. 32) reported that, in the absence of stipulations to minimize the effects of noise, mechanical activities at well sites may disrupt sage-grouse breeding and nesting activities. Hens bred on leks within 3 km (1.9 mi) of oil and gas development in the upper Green River Basin of Wyoming selected nest sites with higher total shrub canopy cover and average live sagebrush height than hens nesting away from disturbance (Lyon 2000, p. 109). The author hypothesized that exposure to road noise associated with oil and gas drilling may have been one cause for the difference in habitat selection. However, noise could not be separated from the potential effects of increased predation resulting from the presence of a new road. In the Pinedale Anticline area of southwest Wyoming, lek attendance declined most noticeably downwind from a drilling rig indicating that noise likely affected male presence (Holloran 2005, p. 49).
Above-ground noise is typically not regulated to mitigate effects to sage-grouse or other wildlife (Connelly
Water quality and quantity may be affected by oil and gas development. In many large field developments, the contamination threat is minimized by storing water produced by the gas dehydration process in tanks. Water also may be depleted from natural sources for drilling or dust suppression purposes. Concentrating wildlife and domestic livestock may increase habitat degradation at remaining water sources. Negative effects of changes in water quality, availability, and distribution are a reduction in habitat quality (e.g., trampling of vegetation, changes in water filtration rates), and habitat degradation (e.g., poor vegetation growth), which could result in brood habitat loss. However, we have no data to suggest that this, by itself, is a limiting factor to sage-grouse.
Water produced by coal-bed methane drilling may benefit sage-grouse through expansion of existing riparian areas and creation of new areas (BLM 2003, p. 4-223). These habitats could provide additional brood rearing and summering habitats for sage-grouse. However, the increased surface-water on the landscape may negatively impact sage-grouse populations by providing an environment for disease vectors (Walker and Naugle in press, p. 13). Based on the 2002 discovery of WNv in the Powder River Basin, and the resulting mortalities of sage-grouse (Naugle
Air quality could be affected where combustion engine emissions, fugitive dust from road use and wind erosion, natural gas-flaring, fugitive emissions from production site equipment, and other activities (BLM 2008d, p. 4-74) occur in sage-grouse habitats. Presumably, as with surface mining, these emissions are quickly dispersed in the windy, open conditions of sagebrush habitats (Moore and Mills 1977, p. 109), minimizing the potential effects on sage-grouse. However, high-density development could produce airborne pollutants that reach or exceed quality standards in localized areas for short periods of time (BLM 2008d, pp. 4-82 to 4-88). Walker (2008, entire) characterized emissions from well flaring in the Pinedale Anticline area of Sublette County, Wyoming. The
Increased human presence resulting from oil and gas development can impact sage-grouse either through avoidance of suitable habitat, disruption of breeding activities, or increased hunting and poaching pressure (Braun
Negative effects of direct habitat disturbance can be offset by successful reclamation. Reclamation of areas disturbed by oil and gas development can be concurrent with field development or conducted after the shut-in or abandonment of the well or field. Sage-grouse may repopulate the area as disturbed areas are reclaimed. However, there is no evidence that populations will attain their previous size, and reestablishment may take 20 to 30 years (Braun 1998, p. 144). For most developments, return to pre-disturbance population levels is not expected due to a net loss and fragmentation of habitat (Braun
Mining began in the range of the sage-grouse before 1900 (State of Wyoming, 1898; U.S. Census 1913, p. 187) and continues today. Currently, surface and subsurface mining activities for numerous resources are conducted in all 11 States across the sage-grouse range. We do not have comprehensive information on the number or surface extent of mines across the range, but the development of mineral resources is occurring in sage-grouse habitats and is important to the economies of a few of the States. Nevada (MZs III, IV, and V) is ranked second in the United States in terms of value of overall nonfuel mineral production in 2006 (USGS 2006, p. 10). Wyoming (MZs I and II) is the largest coal producer in the United States, and the top ten producing mines in the country are located in Wyoming's Powder River Basin (MZ I) (Wyoming Mining Association 2008, p. 2). A preliminary estimate of at least 9.9 km
Uranium mining and milling has occurred in Wyoming, Utah, and Colorado, and Nevada within the greater sage-grouse conservation area; however, recent production has been very limited with only one operation in production in Wyoming (EIA 2009c, entire). Tax credits indicated in the 2005 Energy Policy Act and concerns for green-house gas emissions associated with fossil-fuel electricity generation are expected to increase nuclear power generation (EIA 2009b, p. 73) and stimulate the demand for uranium. Electricity supplied by nuclear plants is expected to increase 2–55 percent by 2030; the increase is dependent on variables such as construction costs and regulatory mandates (EIA 2009b, p. 52), which are difficult to predict. In 2009, industry announced the intent to pursue development (Peninsula Minerals 2009, entire), and the Nuclear Regulatory Commission announced the review of numerous new uranium facilities in Wyoming (74 FR 41174, Uaugust 14, 2009; 74 FR 45656, September 3, 2009). Areas in central Wyoming and Wyoming's Powder River Basin are considered major reserves of uranium coinciding with areas of high sage-grouse population densities (Finch 1996, pp. 19-20; Wyoming State Governor's Sage-grouse Implementation Team 2008, entire).
Bentonite mining has been conducted on over 85 km
Between 2006 and 2007, surface coal production decreased 9 percent in Colorado while increasing by 1.6 and 4.4 percent in Wyoming (MZ I) and Montana (MZ I), respectively (EIA 2008a, entire). The number of Wyoming coal mines increased from 19 in 2005 to 23 in 2008 (Wyoming Mining Association 2005, p. 5). All of Wyoming's 23 coal mines are in sagebrush and in the SGCA. Sixteen of these mines are located in the Powder River Basin (MZ I) where oil and gas development is extensive (Wyoming Mining Association 2008, p. 2).
Coal mining in Montana is focused in the Powder River Basin just north of the Wyoming border, in sagebrush habitat. In Wyoming and Montana, an estimated 558 km
While western coal production has grown steadily since 1970, growth is predicted to increase through 2030, but at a much slower rate than in the past (EIA 2009b, p. 83). Coal production is projected to increase with the development of technology to reduce sulfur emissions and most of the future output of coal is expected from low-sulfur coal mines in Wyoming, Montana, and North Dakota (EIA 2009b, p. 83). We do not have information to quantify the footprint of future coal production; however, additional losses and deterioration of sage-grouse habitats are expected where mining activity occurs (described later in this section). The use of coal may be reduced if limitations on green-house gas emissions are enacted in the future. A transition would require development of lower emission sources, such as wind, solar, or nuclear, that may have their own impacts on sage-grouse environments.
Surface and subsurface mining for mineral resources (coal, uranium, copper, phosphate, aggregate, and others) results in direct loss of habitat if occurring in sagebrush habitats. The direct impact from surface mining is usually greater than it is from subsurface activity. Habitat loss from both types of mining can be exacerbated by the storage of overburden (soil removed to reach subsurface resource)
An increase in human presence increases collision risk with vehicles and potentially exposes sage-grouse and other wildlife to pathogens introduced from septic systems and waste disposal (Moore and Mills 1977, pp. 114-116, 135). Water contamination also could occur from leaching of waste rock and overburden and nutrients from blasting chemicals and fertilizer (Moore and Mills 1977, pp. 115, 133). Altering of water regimes could lead to decreased surface water and eventual habitat degradation from wildlife or livestock concentrating at remaining sources. Sage-grouse do not require water other than what they obtain from plant resources (Schroeder
Mining and associated activities creates an opportunity for invasion of exotic and noxious weed species that alter suitability for sage-grouse (Moore and Mills 1977, pp. 125, 129). Reclamation is required by State and Federal laws, but laws generally allow for a change in post-mining land use. Restoration of sagebrush is difficult to achieve and disturbed sites may never return to suitability for sage-grouse (refer to Habitat Description and Characteristics section).
Heavy equipment operations and use of unpaved roads produces dust that can interfere with plant photosynthesis and insect populations. Most large surface mines are required to control dust. Gaseous emissions generated from heavy equipment operation are quickly dispersed in open, windy areas typical of sagebrush (Moore and Mills 1977, p.109). Blasting, to remove overburden or the target mineral, produces noise and ground shock. The full effect of ground shock on wildlife is unknown. Repeated use of explosives during lekking activity could potentially result in lek or nest abandonment (Moore and Mills 1977, p. 137). Noise from mining activity could mask vocalizations resulting in reduced female attendance and yearling recruitment as seen in sharp-tailed grouse (
A few scientific studies specifically examine the effects of coal mining on greater sage-grouse. In a study in North Park, Colorado, overall sage-grouse population numbers were not reduced, but there was a reduction in the number of males attending leks within 2 km (0.8 mi) of three coal mines, and existing leks failed to recruit yearling males (Braun 1986, pp. 229-230; Remington and Braun 1991, pp. 131-132). New leks formed farther from mining disturbance (Remington and Braun 1991, p. 131). Additionally, some leks that were abandoned adjacent to mine areas were reestablished when mining activities ceased, suggesting disturbance rather than habitat loss was the limiting factor (Remington and Braun 1991, p.132). Hen survival did not decline in a population of sage-grouse near large surface coal mines in northeast Wyoming, and nest success appeared not to be affected by adjacent mining activity (Brown and Clayton 2004, p. 1). However, the authors concluded that continued mining would result in fragmentation and eventually impact sage-grouse persistence if adequate reclamation was not employed (Brown and Clayton 2004, p.16).
Surface coal mining and associated activities have negative short-term impacts on sage-grouse numbers and habitats near mines (Braun 1998, p. 143). Sage-grouse will reestablish on mined areas once mining has ceased, but there is no evidence that population levels will reach their previous size, and any population reestablishment could take 20 to 30 years based on observations of disturbance in oil and gas fields (Braun 1998, p. 144). Local sage-grouse populations could decline if several leks are affected by coal mining, but the loss of one or two leks in a regional area was likely not limiting to local populations in the Caballo Rojo Mine in northeastern Wyoming based on the presence of viable habitat elsewhere in the region (Hayden-Wing Associates 1983, p. 81).
As described above, mining directly removes habitat, may interfere with auditory clues important to mate selection, and results in a decrease of males and inhibits yearling recruitment at leks in proximity to mining activity. Sage-grouse habitat reestablishment and recovery of population numbers in an area post-disturbance is uncertain. Similar avoidance of disturbance has been noted in recent investigations of oil and gas development in Wyoming and discussed in detail in the Nonrenewable Energy section. The studies recounted here were conducted on a local scale that provides limited insight into impacts at a larger landscape perspective. In Wyoming specifically, the cumulative impacts of surface coal mine disturbance, concurrent increases in oil and gas development, increased development of renewable energy resources (discussed in the following section), and transmission infrastructure development could have significant impacts on sage-grouse in the Powder River Basin. The Powder River Basin is home to an important regional population of the larger Wyoming Basin populations covering most of Wyoming, northwestern Colorado, and northeastern Utah (Connelly
The demand for electricity from renewable energy sources is increasing. Electricity production from renewable sources increased from 6.4 quadrillion British thermal units (Btu) in 2005 to 6.9 quadrillion Btu in 2006. Production was down slightly in 2007, but energy production by renewables reached 7.3 quadrillion Btu by the end of 2008 (EIA 2009d, entire). Wind, geothermal, solar and biomass are renewable energy sources developable in sage-grouse habitats. Large-scale hydropower generation occurs in the sage-grouse range in parts of Washington State. Conventional hydropower electrical generation has actually decreased over the past 10 years (EIA 2009d, entire). In general, growth of the renewable energy industry is predictable based on legislated mandates to achieve target levels of renewable-produced electricity in many States within the sage-grouse range.
Areas of commercially viable wind generation have been identified by the NREL (2008b, entire) and BLM (2005, p.
MZs III through VII each have approximately 1 to 14 percent of sagebrush habitats that are commercially developable for wind energy (Service 2008e, entire). Wind harvesting potentials are more concentrated and geographically extensive in sage-grouse MZs I and II that include parts of Montana, Wyoming, North Dakota, and South Dakota; areas of highest commercial potential include 59 percent of the available sagebrush habitats in these four States. Over 30 percent of the sagebrush lands in the sage-grouse range have high potential for wind power (Table 8).
Commercial viability is based on wind intensity and consistency, available markets and access to transmission facilities. Consequently, current development is focused in areas with existing power transmission infrastructure associated with urban development, preexisting conventional energy resource development (e.g., coal and natural gas) and power generation. Growth of wind power development is expected to continue even in the current economic climate (EIA 2009b, p. 3), spurred by statutory mandates or financial incentives to use renewable energy sources in all 11 States in the range (Association of Fish and Wildlife Agencies (AFWA) and Service 2007, pp. 7, 8, 14, 28, 30, 36, 39, 43, 46, 49, 52; State of Oregon 2008, entire).
Wind generating facilities have increased in size and number, outpacing development of other renewable sources in the sage-grouse range. The BLM, the major land manager in the sage-grouse range, developed programmatic guidance to facilitate the use of BLM land for wind development (BLM 2005a, entire). The BLM wind policy permits granting private right-of-ways and leasing of public land for 3–year monitoring and testing facilities and long-term (30 to 35 years) commercial generating facilities (American Wind Energy Association (AWEA) 2008, p. 4-24). Active leases for wind energy development on BLM lands increased from 9.7 km
A recent increase in wind energy development is most notable within the range of the south-central Wyoming subpopulation of greater sage-grouse in MZ II where 1,387 km
In addition to Wyoming, southeastern Oregon is a focus area for potential commercial-scale wind development. Currently, south-central and southeastern Oregon have large areas of relatively unfragmented sage-dominated landscapes which are important for maintaining long-term connectivity between the sage-grouse populations (Knick and Hanser, in press, pp. 1-2.). Historically, central Oregon's population provided connectivity with the Columbia Basin area through narrow habitat corridors (Connelly
Most published reports of the effects of wind development on birds focus on the risks of collision with towers or turbine blades. No published research is specific to the effects of wind farms on the greater sage-grouse. However, the avoidance of human-made structures such as powerlines and roads by sage-grouse and other prairie grouse is documented (Holloran 2005, p. 1; Pruett
Wind farm development begins with site monitoring and collection of meteorological data to accurately characterize the wind regime. Turbines are installed after the meteorological data indicate the appropriate siting and spacing. Roads are necessary to access the turbine sites for installation and maintenance. Each turbine unit has an estimated footprint of 0.4 to 1.2 ha (1 to 3 ac) (BLM 2005a, pp. 3.1-3.4). One or more substations may be constructed depending on the size of the farm. Substation footprints are 2 ha (5 ac) or less in size (BLM 2005a, p. 3.7).
The average footprint of a turbine unit is relatively small from a landscape perspective. Turbines require careful placement within a field to avoid loss of output from interference with neighboring turbines. Spacing improves efficiency but expands the overall footprint of the field. Sage-grouse populations are impacted by the direct loss of habitat, primarily from construction of access roads as well as indirect loss of habitat due to avoidance. Sage-grouse could be killed by flying into turbine rotors or towers (Erickson
Noise is produced by wind turbine mechanical operation (gear boxes, cooling fans) and airfoil interaction with the atmosphere. No published studies have focused specifically on the effects of wind power noise and greater sage-grouse. In studies conducted in oil and gas fields, noise may have played a factor in habitat selection and decrease in lek attendance (Holloran 2005, pp. 49, 56). However, comparison between wind turbine and oil and gas operations is difficult based on the character of sound. Adjusting for manufacturer type and atmospheric conditions, the audible operating sound of a single wind turbine has been calculated as the same level as conversational speech at 1 m (3 ft) at a distance of 600 m (2,000 ft) from the turbine. This level is typical of background levels of a rural environment (BLM 2005a, p. 5-24). However, commercial wind farms do not have a single turbine, and multiple turbines over a large area would likely have a much larger noise print. Low-frequency vibrations created by rotating blades produce annoyance responses in humans (van den Berg 2003, p. 1), but the specific effect on birds is not documented.
Moving blades of turbines cast moving shadows that cause a flickering effect producing a phenomenon called “shadow flicker” (AWEA 2008, p. 5-33). Hypothetically, shadow flicker could mimic predator shadows and elicit an avoidance response in birds during daylight hours, but this potential effect has not been investigated.
Since 2005, states have required an increasing amount of energy to come from renewable sources. For example, Colorado law requires incremental increases of renewable generation from 3 percent in 2007 to 20 percent by 2020 (AFWA and Service 2007, p. 8). Financial incentives, including grants and tax breaks, encourage private development of renewable sources. Although development of renewables is encouraged at a State level, siting authority for wind varies from State to State (AFWA and Service 2007, pp. 7, 8, 14, 28, 30, 36, 39, 43, 46, 49, 52; State of Oregon 2008, entire). For example, the State of Idaho provides tax incentives and loan programs for renewable energy development, but wind power is currently unregulated at any level of government (AFWA and Service 2007, p. 14). The North Dakota Public Service Commission regulates siting of wind power facilities over 100 megawatts using the Service's interim voluntary guidelines (Service 2003, entire).
Wyoming does not have a requirement for increased reliance on renewable energy sources and no specific wind siting authority. However, large construction projects in the State are subject to approval by an Industrial Siting Council (ISC) of the State Department of Environmental Quality, with the WGFD providing recommendations for mitigating impacts to wildlife associated with development considered by the ISC. The ISC's review and approval of projects is subject to the Wyoming Governor's executive order (State of Wyoming 2008, entire) that is intended to prevent harmful effects to sage-grouse from development or new land uses in designated core areas. Wind developers in Wyoming understand that most proposed wind developments regardless of locale must be approved by the ISC and that development proposed in core areas is unlikely to be permitted by the ISC due to the Governor's Executive Order (see discussion in Factor D below).
The BLM manages more land areas of high wind resource potential than any other land management agency. In 2005, the BLM completed the Wind Energy Final Programmatic EIS that provides an overarching guidance for wind project development on BLM-administered lands (BLM 2005a, entire). Best management practices (BMPs) are prescribed to minimize impacts of all phases of construction and operation of a wind production facility. The BMPs guide future project planning and do not guarantee protections specific to sage-grouse. We do not have information on how or where the EIS guidance has been applied since 2005 and cannot evaluate its effectiveness. The footprint of wind energy developments is reported to be
Wind development is guided by policy at BLM national and State levels that generally offers only guidance to avoid impacts to sage-grouse and habitats. A 2008 BLM Instruction Memo IM 2009-43 (BLM 2008e, p. 2) emphasizes the use of the Service's 2003 interim guidelines as voluntary and to be used only on a general basis in siting, design, and monitoring decisions. The BLM's Oregon State Office Instruction Memorandum OR-2008-014 (BLM 2007d, entire) is explicit in the placement of meteorological test towers to avoid active leks, seasonal concentrations, and collision; IM OR-2009-038 (BLM 2009f, entire) reduces the ODFW's recommended buffer distance for wind farms and applies only guidelines for avoidance of sage-grouse leks and seasonal habitats.
Wind energy resources are found throughout the range of the greater sage-grouse, and growth of wind power development is expected to continue. The DOE predicts that wind may provide a significant portion of the nation's energy needs by the year 2030, and substantial growth of wind developments will be required (DOE 2008, p. 1). In mid-2009, wind energy production facilities in the sage-grouse range in operation or under construction had a capacity of 11.93 gigawatts (AWEA 2009, entire) (Table 9). To achieve predicted levels of 49 to greater than 90 gigawatts capacity (DOE 2008, p. 10), the generation capacity will need to increase by 400 to 800 percent by 2030. Existing commercial wind turbines range from 1-2 megawatt generating capacity (AWEA 2009, entire). The forecasted increase in production would require approximately 37,000 to 78,000 or more turbines based on the existing technology and equipment in use. Assuming a generation capacity of 5 megawatts per km
States such as Nevada and Montana that have not been tapped for extensive wind power development are likely to experience significant new energy development within the next 20 years (Table 9). In Wyoming, where wind development is advancing and predicted to increase by 10 fold or more (Table 9), the effects of both conventional and nonconventional renewable sources may claim a substantial toll on sage-grouse habitats and geographic areas that were in the past considered refugia for the species. As with oil and gas development, the average footprint of a turbine unit is relatively small from a landscape perspective, but the effects of large-scale developments have the potential to reduce the size of sagebrush habitats directly, degrade habitats with invasive species, provide pathways for synanthropic predators (i.e., predators that live near and benefit from an association with humans), and cumulatively contribute to habitat fragmentation.
Hydropower development can cause direct habitat losses and possibly an increase in human recreational activity. Reservoirs created concurrently with power generation structures inundated large areas of riparian habitats used by sage-grouse broods (Braun 1998, p. 144). Reservoirs and the availability of irrigation water precipitated conversion of large expanses of upland shrub-steppe habitat in the Columbia Basin adjacent to the rivers (65 FR 51578, August 24, 2000). We were unable to find any information regarding the amount of sage-grouse habitat affected by hydropower projects in other areas of the species' range beyond the Columbia Basin. No new large-scale facilities have been constructed and hydropower electricity generation has decreased steadily over the past 10 years (EIA 2009d, entire). We do not anticipate that future dam construction will result in large losses of sagebrush habitats.
Solar-powered electricity generation is increasing. Between 2005 and the end of 2008, solar electricity generation increased from the equivalent of 66 trillion Btu to 83 trillion Btu (EIA 2009d, entire). Solar-generating systems have been used on a small scale to power individual buildings, small complexes, remote facilities, and signs. Solar energy infrastructure is often ancillary to other development, and large-scale solar-generating systems have not contributed to any calculable direct habitat loss for sage-grouse, but this may change as more systems come on line for commercial electricity generation. Solar energy systems require, depending on local conditions, 1.6 ha (4 ac) to produce 1 megawatt of electricity. For example, the 162-ha (400-ac) Nevada Solar One, the third largest solar electricity producer in the world, has a maximum potential of 75 megawatts from a 121-ha (300-ac) solar field (nevadasolarone.com 2008, entire).
No commercial solar plants are operating in sage-grouse habitats at this time. Southern and eastern Nevada, the Pinedale area of Wyoming, and east-central Utah are the areas of the sage-grouse range with good potential for commercial solar development (EIA 2009e, entire). There are a total of 196 ha (484 ac) of active solar leases on BLM property in northern California (MZ IV) and central Wyoming (MZ II) (BLM 2009g, map) in sagebrush habitats within the current sage-grouse range and these leases will likely be developed. The BLM is developing a programmatic EIS for leasing and development of solar energy on BLM lands. The EIS planning period has been extended to analyze the effects of concentrating large-scale development in selected geographic areas including sage-grouse habitats in east-central Nevada and southern Utah (BLM 2009h, entire) because of the considerable administrative and public interest in developing public lands for solar-generated electricity (BLM 2009i, entire). At this time, we do not have enough information available to evaluate the scale of future impacts of solar power generation in sage-grouse habitats. We will continue to evaluate and monitor the impacts of solar power development in sage-grouse habitats as more information becomes available. We are not aware of any investigations reporting the impacts of solar generating facilities on sage-grouse or other gallinaceous birds. Commercial solar generation could produce direct habitat loss (i.e., solar fields completely eliminate habitat), fragmentation, roads, powerlines, increased human presence, and disturbance during facility construction with similar effects to sage-grouse as reported with oil and gas development.
Geothermal energy production has remained steady since 2005 (EIA 2009d, entire). Geothermal facilities are within the sage-grouse range in California (3 plants, MZ III), Nevada (5 plants, MZs III and V), Utah (2 plants, MZ III), and Idaho (1 plant, MZ IV). Since 2005, two additional plants were constructed is in current sage-grouse range – one in Idaho and one in Utah (Geothermal Energy Association 2008, pp. 2-7). One existing geothermal plant in southern Utah is in the vicinity of sage-grouse habitat in an area where wind power is being considered for development (First Wind-Milford 2009, entire), which will result in cumulative impacts. Geothermal potential occurs across the sage-grouse range in States with existing development and southeast Oregon, west-central Wyoming, and north-central Colorado (EIA 2009e, entire).
Geothermal energy production is similar to oil and gas development such that it requires surface exploration, exploratory drilling, field development, and plant construction and operation. Wells are drilled to access the thermal source and could take from 3 weeks to 2 months of continuous drilling (Suter 1978, p. 3), which may cause disturbance to sage-grouse. The ultimate number of wells, and therefore potential loss of habitat, depends on the thermal output of the well and expected production of the plant (Suter 1978, p. 3). Pipelines are needed to carry steam or superheated liquids to the generating plant which is similar in size to a coal- or gas-fired plant, resulting in further habitat and indirect disturbance. Direct habitat loss occurs from well pads, structures, roads, pipelines and transmission lines, and impacts would be similar to those described previously for oil and gas development.
The development of geothermal energy requires intensive human activity during field development and operation. Geothermal plants could be in remote areas necessitating housing construction, transportation, and utility infrastructure for employees and their families (Suter 1978, p. 12). Geothermal development could cause toxic gas release; the type and effect of these gases depends on the geological formation in which drilling occurs (Suter 1978, pp. 7-9). The amount of water necessary for drilling and condenser cooling may be high. Local water depletions may be a concern if such depletions result in the loss of brood-rearing habitat.
The BLM has the authority to lease geothermal resources in 11 western States. A programmatic EIS for geothermal leasing and operations was completed in 2008 (BLM and USFS 2008a, entire). Best management practices for minimizing the effects of geothermal development and operations on sage-grouse are guidance only and are general in nature (BLM and USFS 2008a, pp. 4.82-4.83). The EIS' reasonably foreseeable development scenario predicts that Nevada will experience the greatest increase in geothermal growth–doubling the production of electricity from geothermal sources by 2025 (BLM and USFS 2008, p. 2-35). Currently, approximately 1,800 km
Energy production from biomass sources has increased every year since 2005 (EIA 2009d, entire). Wood has been a primary biomass source, but corn ethanol and biofuels produced from cultivated crops are on the increase (EIA 2008b, entire). Currently, wood products and corn production do not occur in the range of the sage-grouse in significant quantities (Curtis 2008, p. 7). The National Renewable Energy Laboratory cites potentials for agricultural biomass resources in northern Montana (MZ I), southern Idaho (MZ IV), eastern Washington (MZ VI), eastern Oregon MZ IV), northwest Nevada (MZ V), and southeast Wyoming (MZ II) (NREL 2005, entire). Conversion from native sod to agriculture for the purpose of biomass production could result in a loss of sage-grouse habitat on
Section 368(a) of the Energy Policy Act of 2005 (42 U.S.C. 15926) directs Federal land management agencies to designate corridors on Federal land in 11 western States for oil, gas and hydrogen pipelines and electricity transmission and distribution facilities (energy transport corridors). The agencies completed a programmatic EIS (DOE
It is uncertain how much of the proposed corridors are in sagebrush habitat within the distribution area of sage-grouse, but based on the proposed location, habitat in Wyoming (MZ II), Idaho (MZ IV), Utah (MZ III), Nevada (MZ III) and Oregon (MZs III and IV) would be most affected. The purpose of the corridor designation is to serve a role in expediting applications to construct or modify oil, gas, and hydrogen pipelines and electricity transmission and distribution. These designated areas will likely facilitate the development of novel renewable and nonrenewable electricity generating facilities on public and private lands. Sage-grouse could be impacted through a direct loss of habitat, human activity (especially during construction periods), increased predation, habitat deterioration through the introduction of nonnative plant species, and additional fragmentation of habitat.
Energy development is a significant risk to the greater sage-grouse in the eastern portion of its range (Montana, Wyoming, Colorado, and northeastern Utah – MZs I, II, VII and the northeastern part of MZ III), with the primary concern being the direct effects of energy development on the long-term viability of greater sage-grouse by eliminating habitat, leks, and whole populations and fragmenting some of the last remaining large expanses of habitat necessary for the species' persistence. The intensity of energy development is cyclic and based on many factors including energy demand, market prices, and geopolitical uncertainties. However, continued exploration and development of traditional and nonconventional fossil fuel sources in the eastern portion of the greater sage-grouse range is predicted to continue to increase over the next 20 years (EIA 2009b, p. 109). Greater sage-grouse populations are predicted to decline 7 to 19 percent over the next 20 years due to the effects of oil and gas development in the eastern part of the range (Copeland
Development of commercially viable renewable energy—wind, solar, geothermal, biomass—is increasing across the range with focus in some areas already experiencing traditional energy development (EIA 2009b, pp. 3-4; AWEA 2009a, entire). In Wyoming, where wind development is advancing and predicted to increase by 10-fold (DOE 2008, p. 10), the effects of both conventional and nonconventional and renewable sources may claim a substantial toll on sage-grouse habitats and geographic areas that were in the past considered refugia for the species. Renewable energy resources are likely to be developed in areas previously untouched by traditional energy development. Wind energy resources are being investigated in south-central and southeastern Oregon where large areas of relatively unfragmented sage-dominated landscapes are important for maintaining long-term connectivity within the sage-grouse populations (Knick and Hanser in press, pp. 1-2.).
Greater sage-grouse populations are negatively affected by energy development activities, even when mitigative measures are implemented (Holloran 2005, pp. 57-60; Walker
Development of commercially viable renewable energy–wind, solar, geothermal, biomass–is rapidly increasing rangewide with a focus in some areas already experiencing significant traditional energy development (e.g., MZs I and II). The effects of renewable energy development are likely similar to those of nonrenewable energy as similar types of infrastructure are required. Based on our review of the literature, we anticipate the impacts of these developments will negatively affect the ability of greater sage-grouse to persist in those areas in the foreseeable future.
The Intergovernmental Panel on Climate Change (IPCC) has concluded that warming of the climate is unequivocal, and that continued greenhouse gas emissions at or above current rates will cause further warming (IPCC 2007, p. 30). Eleven of the 12 years from 1995 through 2006 rank among the 12 warmest years in the instrumental record of global surface temperature since 1850 (ISAB 2007). Climate-change scenarios estimate that the mean air temperature could increase by over 3°C (5.4°F) by 2100 (IPCC 2007, p. 46). The IPCC also projects that there will very likely be regional increases in the frequency of hot extremes, heat waves, and heavy precipitation (IPCC 2007, p. 46), as well as increases in atmospheric carbon dioxide (IPCC 2007, p. 36).
We recognize that there are scientific differences of opinion on many aspects of climate change, including the role of natural variability in climate. In our analysis, we rely primarily on synthesis documents (e.g., IPCC 2007; Global Climate Change Impacts in the United States 2009) that present the consensus view of a very large number of experts on climate change from around the world. We have found that these synthesis reports, as well as the scientific papers used in those reports or resulting from those reports, represent the best available scientific information we can use to inform our decision and have relied upon them and provided citation within our analysis. In addition, where possible we have used projections specific to the region of interest, the western United States and southern Canada, which includes the range of the greater sage-grouse. We also use projections of the effects of climate
Projected climate change and its associated consequences have the potential to affect greater sage-grouse and may increase its risk of extinction, as the impacts of climate change interact with other stressors such as disease, and habitat degradation and loss that are already affecting the species (Walker and Naugle, in press, entire; Global Climate Change Impacts in the United States 2009, p. 81; Miller
Climate changes such as shifts in timing and amount of precipitation, and changes in seasonal high and low temperatures, as well as average temperatures, may alter distributions of individual species and ecosystems significantly (Bachelet
Temperature and precipitation both directly influence potential for West Nile virus (WNv) transmission (Walker and Naugle in press, p. 12). In sage-grouse, WNv outbreaks appear to be most severe in years with higher summer temperatures (Walker and Naugle in press, p. 13) and under drought conditions (Epstein and Defilippo, p. 105). This relationship is due to the breeding cycle of the WNv vector,
Emissions of carbon dioxide, considered to be the most important anthropogenic greenhouse gas, increased by approximately 80 percent between 1970 and 2004 due to human activities (IPCC 2007, p. 36). Future carbon dioxide emissions from energy use are projected to increase by 40 to 110 percent over the next few decades, between 2000 and 2030 (IPCC 2007, p. 44). An increase in the atmospheric concentration of carbon dioxide has important implications for greater sage-grouse, beyond those associated with warming temperatures, because higher concentrations of carbon dioxide are favorable for the growth and productivity of
Field studies likewise demonstrate that
Bradley (2009, pp. 196-208) and Bradley
In a study that modeled potential impacts to big sagebrush (
Shafer
Schrag
In some cases, effects of climate change can be demonstrated (e.g., McLaughlin
The direct, long-term impact from climate change to greater sage-grouse is yet to be determined. However, as described above, the invasion of
Greater sage-grouse are a landscape-scale species requiring large, contiguous areas of sagebrush for long-term persistence. Large-scale characteristics within surrounding landscapes influence habitat selection, and adult sage-grouse exhibit a high fidelity to all seasonal habitats, resulting in little adaptability to changes. Fragmentation of sagebrush habitats has been cited as a primary cause of the decline of sage-grouse populations (Patterson 1952, pp. 192-193; Connelly and Braun 1997, p. 4; Braun 1998, p. 140; Johnson and Braun 1999, p. 78; Connelly
We examined several factors that result in habitat loss and fragmentation. Historically, large losses of sagebrush habitats occurred due to conversion for agricultural croplands. This conversion is continuing today, and may increase due to the promotion of biofuel production and new technologies to provide irrigation to arid lands. Indirect effects of agricultural activities, such as linear corridors created by irrigation ditches, also contribute to habitat fragmentation by allowing the incursion of nonnative plants. Direct habitat loss and fragmentation also has occurred as the result of expanding human populations in the western United States, and the resulting urban development in sagebrush habitats.
Fire is one of the primary factors linked to population declines of greater sage-grouse because of long-term loss of sagebrush and conversion to nonnative grasses. Loss of sagebrush habitat to wildfire has been increasing in the western portion of the greater sage-grouse range due to an increase in fire frequency and size. This change is the result of incursion of nonnative annual grasses, primarily
Sage-grouse populations are significantly reduced, including local extirpation, by nonrenewable energy development activities, even when mitigative measures are implemented (Walker
Livestock management and domestic livestock and wild horse grazing have the potential to seriously degrade sage-grouse habitat at local scales through loss of nesting cover, decreasing native vegetation, and successional stage and, therefore, vegetative resiliency, and increasing the probability of incursion of invasive plants. Fencing constructed to manage domestic livestock causes direct mortality, degradation, and fragmentation of habitats, and increased predator populations. There is little direct evidence linking grazing practices to population levels of greater sage-grouse. However, testing for impacts of grazing at landscape scales important to sage-grouse is confounded by the fact that almost all sage-grouse habitat has at one time been grazed, and thus no non-grazed areas currently exist with which to compare. While some rangeland treatments to remove sagebrush for livestock forage production can temporarily increase sage-grouse foraging areas, the predominant effect is habitat loss and fragmentation, although those losses cannot be quantified or spatially analyzed due to lack of data collection.
Restoration of sagebrush habitat is challenging, and restoring habitat function may not be possible because alteration of vegetation, nutrient cycles, topsoil, and cryptobiotic crusts have exceeded recovery thresholds. Even if possible, restoration will require decades and will be cost-prohibitive. To provide habitat for sage-grouse, restoration must include all seasonal habitats and occur on a large scale (4,047 ha (10,000 ac) or more) to provide all necessary habitat components. Restoration may never be achieved in the presence of invasive grass species.
The WAFWA identified a goal of “no net loss” of birds and habitat in their Greater Sage-grouse Comprehensive Conservation Strategy (Stiver
In order to assess the effects of habitat loss and fragmentation on greater sage-grouse populations and persistence, we examined a variety of data to understand how population trends reflected the changing habitat condition. Patterns of sage-grouse extirpation were identified by Aldridge
Lek count data are the only data available to estimate sage-grouse population trends, and are the data WAFWA collects (WAFWA 2008, p. 3). The use of lek count data as an index of trends involves various types of uncertainty (such as measurement error, count methods, statistical and other types of assumptions; e.g. see Connelly
Population trends (average number of males per lek) in MZs I and II, the areas with the highest concentration of nonrenewable energy development, decreased by 17 and 30 percent from 1965 to 2007, respectively (Garton
In some populations within the species' range, population trends (number of males counted on leks) since the early 1990s appear to be stable, and in some cases increasing (Garton
As described above, our analysis of habitat trends, and those provided in the published literature show that population extirpation and declines have, and are likely to continue to track habitat loss or environmental changes (e.g., Walker
Garton
Garton
One assumption made by Garton
In all MZs, the analyses by Garton
Garton
Garton
In MZ IV, Garton
In MZ V, Garton
Carrying capacity projections could not be estimated for MZ VII due to insufficient data. Energy development activities occur within most populations in this area, and Johnson (in press, p. 13) reported that lek attendance was lower around producing wells in this MZ. We believe that based on habitat impacts, if birds are retained in this area, the populations will be reduced in size and further isolated.
The projections from Garton
The population and carrying capacity projections by Garton
We examined the persistence of each of these habitat threats on the landscape to help inform a determination of foreseeable future. Habitat conversion and fragmentation resulting from agricultural activities and urbanization will continue indefinitely. Human
Continued exploration and development of traditional and nonconventional fossil fuel sources in the eastern portion of the greater sage-grouse range will continue to increase over the next 20 years (EIA 2009b, p. 109). Based on existing National Environmental Policy Act (NEPA) documents for major oil and gas developments, production within existing developments will continue for a minimum of 20 years, with subsequent restoration (if possible) requiring from 30 to 50 additional years. Renewable energy development is estimated to reach maximum development by 2030. However, since most renewable energy facilities are permanent landscape features, unlike oil, gas and coal, direct and functional habitat loss from the development footprint will be permanent. Based on this information, we estimate the foreseeable future of energy development at a minimum of 50 years, and perhaps much longer for nonrenewable sources.
Grazing (both domestic and wild horse and burro) is unlikely to be removed from sagebrush ecosystems. Therefore, it is difficult to estimate a foreseeable future for livestock grazing. However, as of 2007, there were 7,118,989 permitted AUMs in sage-grouse habitat. Although there have been recent reductions in the number of AUMs (3.4 percent since 2005), we have no information suggesting that livestock grazing will be significantly reduced, or removed, from sage-grouse habitats. Therefore, while we cannot provide an exact estimate of the foreseeable future for grazing, we expect it to be a persistent use of the sage-grouse landscape for several decades.
As identified above in our Factor A analysis, habitat conversion for agriculture, urbanization, infrastructure (e.g., roads, powerlines, fences); fire, invasive plants, pinyon-juniper woodland encroachment, grazing, energy development, and climate change are all contributing, individually and collectively, to the present and threatened destruction, modification, and curtailment of the habitat and range of the greater sage-grouse. The impacts are compounded by the fragmented nature of this habitat loss, as fragmentation results in functional loss of habitat for greater sage-grouse even when otherwise suitable habitat is still present.
Fragmentation of sagebrush habitats is a key cause, if not the primary cause, of the decline of sage-grouse populations. Fragmentation can make otherwise suitable habitat either too small or isolated to be of use to greater sage-grouse (i.e., functional habitat destruction), or the abundance of sage-grouse that can be supported in an area is diminished. Fire, invasive plants, energy development, various types of infrastructure, and agricultural conversion have resulted in habitat fragmentation and additional fragmentation is expected to continue for the foreseeable future in some areas.
In our evaluation of Factor A, we found that although many of the habitat impacts we analyzed (e.g, fire, urbanization, invasive species) are present throughout the range, they are not at a level that is causing a threat to greater sage-grouse everywhere within its range. Some threats are of high intensity in some areas but are low or nonexistent in other areas. Fire and invasive plants, and the interaction between them, is more pervasive in the western part of the range than in the eastern. Oil and gas development is having a high impact on habitat in many areas in the eastern part of the range, but a low impact further to the west. The impact of pinyon-juniper encroachment generally is greater in western areas of the range, but is of less concern in more eastern areas such as Wyoming and Montana. Agricultural development is high in the Columbia Basin, Snake River Plain, and eastern Montana, but low elsewhere. Infrastructure of various types is present throughout the most of range of the greater sage-grouse, as is livestock grazing, but the degree of impact varies depending on grazing management practices and local ecological conditions. The degree of urbanization and exurban development varies across the range, with some areas having relatively low impact to habitat.
While sage-grouse habitat has been lost or altered in many portions of the species' range, habitat still remains to support the species in many areas of its range (Connelly
As stated above, the impacts to habitat are not uniform across the range; some areas have experienced less habitat loss than others, and some areas are at relatively lower risk than others for future habitat destruction or modification. Nevertheless, the impacts are substantial in many areas and will continue or even increase in the future across much of the range of the species. With continued habitat destruction and modification, resulting in fragmentation and diminished connectivity, greater sage-grouse populations will likely decline in size and become more isolated, making them more vulnerable to further reduction over time and increasing the risk of extinction.
We have evaluated the best scientific and commercial information available regarding the present or threatened destruction, modification, or curtailment of the greater sage-grouse's habitat or range. Based on the current and ongoing habitat issues identified here, their synergistic effects, and their likely continuation in the future, we conclude that this threat is significant such that it provides a basis for determining that the species warrants listing under the Act as a threatened or endangered species.
The greater sage-grouse was heavily exploited by commercial hunting in the late 1800s and early 1900s (Patterson 1952, pp. 30-32; Autenrieth 1981, pp. 3-11). Hornaday (1916, pp. 179-221) and others alerted the public to the risk of
With the increase of sage-grouse populations by the 1950s, limited recreational hunting seasons were allowed in most of the species' range (Patterson 1952, p. 242; Autenrieth 1981, p.11). Currently, greater sage-grouse are legally sport-hunted in 10 of 11 States where they occur (Connelly
Harvest levels have varied considerably since the 1950s, and in recent years have been much lower than in past decades (Figure 3) (Service 2009, unpublished data). From 1960 to 1980, the majority of sage-grouse hunting mortality occurred in Wyoming, Idaho, and Montana, accounting for at least 75 to 85 percent of the annual harvest (Service 2009, unpublished data). In the 1960s harvest exceeded 120,000 individuals annually for 7 out of 10 years. Harvest levels reached a maximum in the 1970s, being above 200,000 individuals in 9 of 10 years with the total estimate at 2,322,581 birds harvested for the decade. During the 1980s, harvest exceeded 130,000 individuals in 9 of 10 years (Service 2009, unpublished data). The harvest was above 100,000 annually during the early 1990s but in 1994 dropped below 100,000 for the first time in decades. From 2000 to 2007, annual harvest has averaged approximately 31,000 birds (Service 2009, unpublished data).
Sustainable harvest is determined based on the concept of compensatory and additive mortality (Connelly 2005, p. 7). The compensatory mortality hypothesis asserts that if sage-grouse produce more offspring than can survive to sexual maturity, individuals lost to hunting represent losses that would have occurred otherwise from some other source (e.g., starvation, predation, disease). Hunting mortality is termed additive if it exceeds natural mortality and ultimately results in a decline of the breeding population. The validity of compensatory mortality in upland gamebirds has not been rigorously tested, and as we stated above, annual
The validity of the idea that hunting is a form of compensatory mortality for upland game birds has been questioned in recent years (Reese and Connelly, in press, p. 6). Connelly
Numerous contradictions are likely due to differing methods, lack of experimental data, and differing effects of harvest due to a relationship between harvest and habitat quality. For example, Connelly
Sage-grouse hunting is regulated by State wildlife agencies. Hunting seasons are reviewed annually, and States change harvest management based on estimates for spring production and population size (e.g., Bohne 2003, pp.1-10). However, harvest affects fall populations of sage-grouse, and currently there is no reliable method for obtaining estimates of fall population size (Connelly
Female survivorship is a key element of population productivity. Harvest might affect female and male grouse differently. Connelly
All States with hunting seasons have changed limits and season dates to more evenly distribute hunting mortality across the entire population structure of greater sage-grouse, harvesting birds after females have left their broods (Bohne 2003, p. 5). Females and broods congregate in mesic areas late in the summer potentially making them more vulnerable to hunting (Connelly
Harvest management levels that are based on the concept of compensatory mortality assume that overwinter mortality is high, which is not true for sage-grouse (winter mortality rates approximately 2 percent, Connelly
State management agencies have become increasingly responsive to these concerns. All of the States where hunting greater sage-grouse is legal,
All ten States that allow bow and gun hunting of sage-grouse also allow falconers to hunt sage-grouse. Falconry seasons are typically longer (60 to 214 days), and in some cases have larger bag limits than bow/gun seasons. However, due to the low numbers of falconers and their dispersed activities, the resulting harvest is thought to be negligible (Apa 2008, pers. comm.; Northrup 2008, pers. comm.; Hemker 2008, pers. comm.; Olsen 2008, pers. comm.; Kanta 2008, pers. comm.). Wyoming is one of the few States that collects falconry harvest data and reported a take of 180 sage-grouse by falconers in the 2006-2007 season (WGFD 2007, unpublished data). In Oregon, the take is probably less than five birds per year (Budeau 2008, pers. comm.). In Idaho the 2005 estimated Statewide falconry harvest was 77 birds, and that number has likely remained relatively constant (Hemker 2008, pers. comm.). We are not aware of any studies that have examined falconry take of greater sage-grouse in relation to population trends, but the amount of greater sage-grouse mortality associated with falcon sport hunting appears to be negligible.
We surveyed the State fish and wildlife agencies within the range of greater sage-grouse to determine what information they had on illegal harvest (poaching) of the species. Nevada and Utah indicated they were aware of citations being issued for sage-grouse poaching, but that it was rare (Espinosa 2008, pers. comm.; Olsen 2008, pers. comm.). Sage-grouse wings are infrequently discovered in wing-barrel collection sites during forest grouse hunts in Washington, but such take is considered a result of hunter misidentification rather than deliberate poaching (Schroeder 2008, pers. comm.). None of the remaining States had any quantitative data on the level of poaching. Based on these results, illegal harvest of greater sage-grouse poaching appears to occur at low levels. We are not aware of any studies or other data that demonstrate that poaching has contributed to sage-grouse population declines.
Greater sage-grouse are subject to a variety of non-consumptive recreational uses such as bird watching or tour groups visiting leks, general wildlife viewing, and photography. Daily human disturbances on sage-grouse leks could cause a reduction in mating and some reduction in total production (Call and Maser 1985, p. 19). Overall, a relatively small number of leks in each State receive regular viewing use by humans during the strutting season and most States report no known impacts from this use (Apa 2008, pers. comm.; Christiansen 2008, pers. comm.; Gardner 2008, pers. comm.; Northrup 2008, pers. comm.). Only Colorado has collected data regarding the effects of non-consumptive use. Their analyses suggest that controlled lek visitation has not impacted greater sage-grouse (Apa 2008, pers. comm.). However, Oregon reported anecdotal evidence of negative impacts of unregulated viewing to individual leks near urban areas that are subject to frequent disturbance from visitors (Hagen 2008, pers. comm.).
To reduce any potential impact of lek viewing on sage-grouse, several States have implemented measures to protect most leks while allowing recreational viewing to continue. The Wyoming Game and Fish Department (WGFD) provides the public with directions to 16 leks and guidelines to minimize viewing disturbance. Leks included in the brochure are close to roads and already subject to some level of disturbance (Christiansen 2008, pers. comm.); presumably, focusing attention on these areas reduces pressure on relatively undisturbed leks. Colorado and Montana have some sites with viewing trailers for the public for the same reasons (Apa 2008, pers. comm.; Northrup 2008, pers. comm.). We were not able to locate any studies documenting how lek viewing, or other forms of non-consumptive recreational uses, of sage-grouse are related to sage-grouse population trends. Given the relatively small number of leks visited, we have no reason to believe that this type of recreational activity is having a negative impact on local populations or contributing to declining population trends.
Some Native American tribes harvest greater sage-grouse as part of their religious or ceremonial practices as well as for subsistence. Native American hunting occurs on the Wind River Indian Reservation (Wyoming), with about 20 males per year taken off of leks in the spring plus an average fall harvest of approximately 40 birds (Hnilicka 2008, pers. comm.). The Shoshone-Bannock Tribe (Idaho) occasionally takes small numbers of birds in the spring, but no harvest figures have been reported for 2007 and 2008 (Christopherson 2008, pers. comm.). The Shoshone-Paiute Tribe of the Duck Valley Indian Reservation (Idaho and Nevada) suspended hunting in 2006 to 2009 due to significant population declines resulting from a WNv outbreak in the area (Dick 2009, pers. comm.; Gossett 2008, pers. comm.). Prior to 2006, the sage-grouse hunting season on the Duck Valley Indian Reservation ran from July 1 to November 30 with no bag or possession limits. Preliminary estimates indicate that the harvest may have been as high as 25 percent of the population (Gossett 2008, pers. comm.). Despite the hunting ban, populations have not recovered on the reservation (Dick 2009, pers. comm.; Gossett 2008, pers. comm.). No harvest by Native Americans for subsistence or religious and ceremonial purposes occurs in South Dakota, North Dakota, Colorado, Washington, or Oregon (Apa 2008, pers. comm.; Hagen 2008, pers. comm.; Kanta 2008, pers. comm.; Robinson 2008, pers. comm.; Schroeder 2008, pers. comm.).
Greater sage-grouse are the subject of many scientific research studies. We are aware of some 51 studies ongoing or completed during 2005 and 2008. Of the 11 western States where sage-grouse currently occur, all reported some type of field studies that included the capture, handling, and subsequent banding, or banding and radio-tagging of sage-grouse. In 2005, the overall mortality rate due to the capture, handling, and/or radio-tagging process was calculated at approximately 2.7 percent of the birds captured (68 mortalities of 2,491 captured). A survey of State agencies, BLM, consulting companies, and graduate students involved in sage-grouse research indicates that there has been little change in direct handling mortality since then. We are not aware of any studies that document that this level of taking has affected any sage-grouse population trends.
Greater sage-grouse have been translocated in several States and the Province of British Columbia (Reese and Connelly 1997, p. 235). Reese and Connelly (1997, pp. 235-238)
Greater sage-grouse are not used for any commercial purpose. In Canada, hunting of sage-grouse is prohibited in Alberta and Saskatchewan. In the United States, sage-grouse hunting is regulated by State wildlife agencies and hunting regulations are reevaluated yearly. We have no information that suggests any change will occur in the current situation, in which hunting greater sage-grouse is prohibited in Washington and allowed elsewhere in the range of the species in the U.S. under State regulations, which provide a basis for adjustments in annual harvest and emergency closures of hunting seasons. We have no evidence suggesting that gun and bow sport hunting has been a primary cause of range-wide declines of the greater sage-grouse in the past, or that it currently is at level that poses a significant threat to the species. However, although harvest as a singular factor does not appear to threaten the species throughout its range, negative impacts on local populations have been demonstrated and there remains a large amount of uncertainty regarding harvest impacts because of a lack of experimental evidence and conflicting studies. Significant habitat loss and fragmentation have occurred during the past several decades, and there is evidence that the sustainability of harvest levels depends to a large extent upon the quality of habitat and the health of the population. However, recognition that habitat loss is a limiting factor is not conclusive evidence that hunting has played no role in population declines or that reducing or eliminating harvest will not have an effect on population stability or recovery.
Take from poaching (illegal hunting) appears to occur at low levels in localized areas, and there is no evidence that it contributes to population declines. The information on non-consumptive recreational activities is limited to lek viewing, the extent of such activity is small, and there is no indication that it has a negative impact that contributes to population declines. Harvest by Native American tribes, and mortality that results from handling greater sage-grouse for scientific purposes appears to occur at low levels in localized areas and thus we do not consider these to be a significant threat at either the rangewide or local population levels. We know of no utilization for educational purposes. We have no reason to believe any of the above activities will increase in the future.
We do not believe data support overuse of sage-grouse as a singular factor in rangewide population declines. We note, however, that in light of present and threatened habitat loss (Factor A) and other considerations (e.g. West Nile virus outbreaks in local populations), continued close attention will be needed by States and tribes to carefully manage hunting mortality, including adjusting seasons and allowable harvest levels, and imposing emergency closures if needed.
In sum, we find that this threat is not significant to the species such that it causes the species to warrant listing under the Act.
Greater sage-grouse are hosts for a variety parasites and diseases, including macroparasitic arthropods, helminths and microparasites (protozoa, bacteria, viruses and fungi) (Thorne
Internal parasites which have been documented in the greater sage-grouse include the protozoans
Greater sage-grouse host many external parasites, including lice, ticks, and dipterans (midges, flies, mosquitoes, and keds) (Connelly
Only a few parasitic infections in greater sage-grouse have been documented to result in fatalities, including the protozoan,
The only mortalities associated with ixodid ticks were found in association with a tularemia (
Greater sage-grouse also are subject to a variety of bacterial, fungal, and viral pathogens. The bacteria
Sage-grouse afflicted with coccidiosis in Wyoming also were positive for
One case of aspergillosis, a fungal disease, has been documented in sage-grouse, but there is no evidence to suggest this fungus plays a role in limiting greater sage-grouse populations (Connelly
Viruses could cause serious diseases in grouse species and potentially influence population dynamics (Petersen 2004, p. 46). However, prior to 2002, only avian infectious bronchitis (caused by a coronavirus) had been identified in the greater sage-grouse during necropsy. No clinical signs of the disease were observed.
West Nile virus was introduced into the northeastern United States in 1999 and has subsequently spread across North America (Marra
Impacts of WNv on the bird host varies by species with some species being relatively unaffected (e.g., common grackles (
In sagebrush habitats, WNv transmission is primarily regulated by environmental factors, including temperature, precipitation, and anthropogenic water sources, such as stock ponds and coal-bed methane ponds, that support the mosquito vectors (Reisen
Greater sage-grouse inhabiting higher elevation sites in summer are likely less vulnerable to contracting WNv than birds at lower elevation as ambient temperatures are typically cooler (Walker and Naugle in press, p. 11). Greater sage-grouse populations in northwestern Colorado and western Wyoming are examples of high elevation populations with lower risk for impacts from WNv (Walker and Naugle in press, p. 26). Also, due to
The primary vector of WNv in sagebrush ecosystems is
In greater sage-grouse, mortality from WNv occurs at a time of year when survival is otherwise typically high for adult females (Schroeder
WNv was first detected in 2002 as a cause of greater sage-grouse mortalities in Wyoming (Walker and Naugle in press, p. 15). Data from four studies in the eastern half of the sage-grouse range (Alberta, Montana, and Wyoming; MZ I) showed survival in these populations declined 25 percent in July and August of 2003 as a result of the WNv infection (Naugle
Eight sage-grouse deaths resulting from WNv were identified in 2004: four from the Powder River Basin area of northeastern Wyoming and southeastern Montana, one from the northwestern Colorado, near the town of Yampa, and three in California (Naugle
Mortality rates from WNv in northeastern Wyoming and southeastern Montana (MZ I) were between 2.4 (estimated minimum) and 28.9 percent (estimated maximum) in 2005 (Walker
In 2007, a WNv outbreak in South Dakota contributed to a 44-percent mortality rate among 80 marked females (Walker and Naugle in press, p. 18). Juvenile mortality rates in 2007 in the same area ranged from 20.8 to 62.5 percent (Kaczor 2008, p. 63), reducing recruitment the subsequent spring by 2 to 4 percent (Kaczor 2008, p. 65). Twenty-six percent of radio-marked females in northeastern Montana died during a 2–week period immediately following the first detection of WNv in mosquito pools. Two of those females were confirmed dead from WNv (Walker and Naugle in press, p. 18). In the Powder River Basin, WNv-related mortality among 85 marked females was between 8 and 21 percent (Walker and Naugle in press, p. 18). A 52-percent decline in the number of males attending leks in North Dakota between 2007 and 2008 also were associated with WNv mortality in 2007 that prompted the State wildlife agency to close the hunting season in 2008 (North Dakota Game and Fish 2008, entire) and 2009 (Robinson 2009, pers. comm.). The Duck Valley Indian Reservation along the border of Nevada and Idaho closed their hunting season in 2006 due to population declines resulting from WNv (Gossett 2008, pers. comm.). WNv is still present in that area, with continued population declines (50.3 percent of average males per lek from 2005 to 2008) (Dick 2008, p. 2), and the hunting season remains closed. The hunting season was closed in most of the adjacent Owyhee County, Idaho for the same reason in both 2008 and 2009 (Dick 2008, pers. comm.; IDFG 2009).
Only Wyoming reported WNv mortalities in sage-grouse in 2008 (Cornish 2009c, pers. comm.). However, with the exceptions of Colorado, California, and Idaho, research on sage-grouse in other States is limited, minimizing the ability to identify mortalities from the disease, or recover infected birds before tissue deterioration precludes testing. Three sage-grouse deaths were confirmed in 2009 in Wyoming (Cornish 2009c, pers. comm.), two in Idaho (Moser 2009, pers. comm.)
Greater sage-grouse deaths resulting from WNv have been detected in 10 States and 1 Canadian province. To date, no sage-grouse mortality from WNv has been identified in either Washington State or Saskatchewan. However, it is likely that sage-grouse have been infected in Saskatchewan based on known patterns of sage-grouse in infected areas of Montana (Walker and Naugle in press, p. 15). Also, WNv has been detected in other species within the range of greater sage-grouse in Washington (USGS 2009).
In 2005, we reported that there was little evidence that greater sage-grouse can survive a WNv infection (70 FR 2270). This conclusion was based on the lack of sage-grouse found to have antibodies to the virus and from laboratory studies in which all sage-grouse exposed to the virus, at varying doses, died within 8 days or less (70 FR 2270; Clark
The duration of immunity conferred by surviving an infection is unknown (Walker and Naugle in press, p. 20). It also is unclear whether sage-grouse have sub-lethal or residual effects resulting from a WNv infection, such as reduced productivity or overwinter survival (Walker
Several variants of WNv have emerged since the original identification of the disease in the United States in 1999. One variant, termed NY99, has proven to be more virulent than the original virus strain of WNv, increasing the frequency of disease cycling (Miller 2009, pers. comm.). This constant evolution of the virus could limit resistance development in the greater sage-grouse.
Walker and Naugle (in press, pp. 20-24) modeled variability in greater sage-grouse population growth for the next 20 years based on current conditions under three WNv impact scenarios. These scenarios included: (1) no mortalities from WNv; (2) WNv- related mortality based on rates of observed infection and mortality rate data from 2003 to 2007; and (3) WNv-related mortality with increasing resistance to the disease over time. The addition of WNv-related mortality (scenario 2) resulted in a reduction of population growth. The proportion of resistant individuals in the modeled population increased marginally over the 20–year projection periods, from 4 to 15 percent, under the increasing resistance scenario (scenario 3). While this increase in the proportion of resistant individuals did reduce the projected WNv rates, the authors caution that the presence of neutralizing antibodies in the live birds does not always indicate that these birds are actually resistant to infection and disease (Walker and Naugle in press, p. 25).
Additional models predicting the prevalence of WNv suggest that new sources of anthropogenic surface waters (e.g., coal-bed methane discharge ponds), increasing ambient temperatures, and a mosquito parasite that reduces the length of time the virus is present in the vector before the mosquito can spread the virus all suggest the impacts of this disease are likely to increase (Miller 2008, pers. comm.). However, the extent to which this will occur, and where, is unclear and difficult to predict because several conditions that support the WNv cycle must coincide for an outbreak to occur.
Human-created water sources in sage-grouse habitat known to support breeding mosquitoes that transmit WNv include overflowing stock tanks, stock ponds, irrigated agricultural fields, and coal-bed natural gas discharge ponds (Zou
The long-term response of different sage-grouse populations to WNv infections is expected to vary markedly depending on factors that influence exposure and susceptibility, such as temperature, land uses, and sage-grouse population size (Walker and Naugle in press, p. 25). Small, isolated, or genetically limited populations are at higher risk as an infection may reduce population size below a threshold where recovery is no longer possible, as observed with the extirpated population near Spotted Horse, Wyoming (Walker and Naugle in press, p. 25). Larger populations may be able to absorb impacts resulting from WNv as long as the quality and extent of available habitat supports positive population growth (Walker and Naugle in press, p. 25). However, impacts from this disease may act synergistically with other stressors resulting in reduction of population size, bird distribution, or persistence (Walker
Proactive measures to reduce the impact of WNv on greater sage-grouse have been limited and are typically economically prohibitive. Fowl vaccines used on captive sage-grouse were largely ineffective (mortality rates were reduced from 100 to 80 percent in five birds) (Clark
Mosquito production from human-created water sources could be minimized if water produced during coal-bed natural gas development were re-injected rather than discharged to the surface (Doherty 2007, p. 81). Mosquito control programs for reducing the number of adult mosquitoes may reduce the risk of WNv, but only if such methods are consistently and appropriately implemented (Walker and Naugle in press, p. 28). Many coal-bed natural gas companies in northeastern Wyoming (MZ I) have identified use of mosquito larvicides in their management plans (Big Horn Environmental Consultants in litt., 2009, p. 3). However, we could find no information on the actual use of the larvicides or their effectiveness. One experimental treatment in the area did report that mosquito larvae numbers were less in ponds treated with larvicides than those that were not (Big Horn Environmental Consultants in litt., 2009, pp. 5-7) but statistical analyses were not conducted. While none of the sage-grouse mortalities in the treated areas were due to WNv (Big Horn Environmental Consultants 2009, p.3), the study design precluded actual cause and effect analyses; therefore, the results are inconclusive. The benefits of mosquito control in potentially reducing the incidence of WNv in sage-grouse need to be considered in light of the potential detrimental or cascading ecological effects of widespread spraying (Marra
Small populations, such as the Columbia Basin area in Washington State or the subpopulations within the Bi-State area along the California and Nevada border also may be at high risk of extirpation simply due to their low population numbers and the additive mortality WNv causes (Christiansen and Tate, in press, p. 21). Larger populations may be better able to sustain losses from WNv (Walker and Naugle in press, p. 25) simply due to their size. However, as other impacts to grouse and their habitats described under Factor A affect these areas, these secure areas or sage-grouse “refugia” also may be at risk (e.g., southwestern Wyoming, south-central Oregon). Existing and developing models suggest that the occurrence of WNv is likely to increase throughout the range of the species into the future.
Although greater sage-grouse are host to a wide variety of diseases and parasites, few have resulted in population effects, with the exception of WNv. Many large losses from bacterial and coccidial infections have resulted when large groups of grouse were restricted to limited habitats, such as springs and seeps in the late summer. If these habitats become restricted due to habitat losses and degradation, or changes in climate, these easily transmissible diseases may become more prevalent. Sub-lethal effects of these disease and parasitic infections on sage-grouse have never been studied, and, therefore, are unknown.
Substantial new information on WNv and impacts on the greater sage-grouse has emerged since we completed our finding in 2005. The virus is now distributed throughout the species' range, and affected sage-grouse populations experience high mortality rates with resultant, often large reductions in local population numbers. Infections in northeastern Wyoming, southeastern Montana, and the Dakotas seem to be the most persistent, with mortalities recorded in that area every year since WNv was first detected in sage-grouse. Limited information suggests that sage-grouse may be able to survive an infection; however, because of the apparent low level of immunity and continuing changes within the virus, widespread resistance is unlikely.
There are few regular monitoring efforts for WNv in greater sage-grouse; most detection is the result of research with radio-marked birds, or the incidental discovery of large mortalities. In Saskatchewan, where the greater sage-grouse is listed as an endangered species, no monitoring for WNv occurs (McAdams 2009, pers. comm.). Without a comprehensive monitoring program, the extent and effects of this disease on greater sage-grouse rangewide cannot be determined. However, it is clear that WNv is persistent throughout the range of the greater sage-grouse, and is likely a locally significant mortality factor. We anticipate that WNv will persist within sage-grouse habitats indefinitely, and will remain a threat to greater sage-grouse until they develop a resistance to the virus.
The most significant environmental factors affecting the persistence of WNv within the range of sage-grouse are ambient temperatures and surface water abundance and development. The continued development of anthropogenic sources of warm standing water throughout the range of the species will likely increase the prevalence of the virus in sage-grouse, as predicted by Walker and Naugle (in press, pp. 20-24; see discussion above). Areas with intensive energy development may be at a particularly high risk for continued WNv mortalities due to the development of surface water features, and the continued loss and fragmentation of habitats (see discussion of energy development above). Resultant changes in temperature as a result of climate change also may exacerbate the prevalence of WNv and thereby impacts on greater sage-grouse unless they develop resistance to the virus.
With the exception of WNv, we could find no evidence that disease is a concern with regard to sage-grouse persistence across the species' range. WNv is a significant mortality factor for greater sage-grouse when an outbreak occurs, given the bird's lack of resistance and the continued proliferation of water sources throughout the range of the species. However, a complex set of environmental and biotic conditions that support the WNv cycle must coincide for an outbreak to occur. Currently the annual patchy distribution of the disease is keeping the impacts at a minimum. The prevalence of this disease is likely to increase across the species' range.
We find that the threat of disease is not significant to the point that the greater sage-grouse warrants listing under the Act as threatened or endangered at this time.
Predation is the most commonly identified cause of direct mortality for sage-grouse during all life stages (Schroeder
Major predators of adult sage-grouse include many species of diurnal raptors (especially the golden eagle), red foxes, and bobcats (
Adult male greater sage-grouse are very susceptible to predation while on the lek (Schroeder
Estimates of predation rates on juveniles are limited due to the difficulties in studying this age class (Aldridge and Boyce 2007, p. 509; Hagen in press, p.8). Chick mortality from predation ranged from 27 percent to 51 percent in 2002 and 10 percent to 43 percent in 2003 on three study sites in Oregon (Gregg
Sage-grouse nests are subject to varying levels of predation. Predation can be total (all eggs destroyed) or partial (one or more eggs destroyed). However, hens abandon nests in either case (Coates, 2007, p. 26). Gregg
Nesting success of greater sage-grouse is positively correlated with the presence of big sagebrush and grass and forb cover (Connelly
In a review of published nesting studies, Connelly
Abundance of red fox and corvids, which historically were rare in the sagebrush landscape, has increased in association with human-altered landscapes (Sovada
Raven abundance has increased as much as 1500 percent in some areas of western North America since the 1960s (Coates and Delehanty 2010, p. 244 and references therein). Human-made structures in the environment increase the effect of raven predation, particularly in low canopy cover areas, by providing ravens with perches (Braun 1998, pp.145-146; Coates 2007, p. 155; Bui 2009, p. 2). Reduction in patch size and diversity of sagebrush habitat, as well as the construction of fences, powerlines, and other infrastructure also are likely to encourage the presence of the common raven (Coates
Holloran (2005, p. 58) attributed increased sage-grouse nest depredation to high corvid abundances, which resulted from anthropogenic food and perching subsidies in areas of natural gas development in western Wyoming. Bui (2009, p. 31) also found that ravens used road networks associated with oil fields in the same Wyoming location for foraging activities. Holmes (unpubl. data) also found that common raven abundance increased in association with oil and gas development in southwestern Wyoming. The influence of synanthropic predators in the Wyoming Basin is important as this area has one of the few remaining clusters of sagebrush landscapes and the most highly connected network of sage-grouse leks (Knick and Hanser in press, p.18). Raven abundance was strongly associated with sage-grouse nest failure in northeastern Nevada, with resultant negative effects on sage-grouse reproduction (Coates 2007, p. 130). The presence of high numbers of predators within a sage-grouse nesting area may negatively affect sage-grouse productivity without causing direct mortality. Coates (2007, p. 85-86) suggested that ravens may reduce the time spent off the nest by female sage-grouse, thereby potentially compromising their ability to secure sufficient nutrition to complete the incubation period.
As more suitable grouse habitat is converted to oil fields, agriculture and other exurban development, grouse nesting and brood-rearing become increasingly spatially restricted (Bui 2009, p. 32). High nest densities which result from habitat fragmentation or disturbance associated with the presence of edges, fencerows, or trails may increase predation rates by making foraging easier for predators (Holloran 2005, p. C37). In some areas even low but consistent raven presence can have a major impact on sage-grouse reproductive behavior (Bui 2009, p. 32). Leu and Hanser (in press, pp. 24-25) determined that the influence of the human footprint in sagebrush ecosystems may be underestimated due to varying quality of spatial data. Therefore, the influence of ravens and other predators associated with human activities may be under-estimated.
Predator removal efforts have sometimes shown short-term gains that may benefit fall populations, but not breeding population sizes (Cote and Sutherland 1997, p. 402; Hagen in press, p. 9; Leu and Hanser in press, p. 27). Predator removal may have greater benefits in areas with low habitat quality, but predator numbers quickly rebound without continual control (Hagen in press, p. 9). Red fox removal in Utah appeared to increase adult sage-grouse survival and productivity, but the study did not compare these rates against other non-removal areas, so inferences are limited (Hagen in press, p. 11). Slater (2003, p. 133) demonstrated that coyote control failed to have an effect on greater sage-grouse nesting success in southwestern Wyoming. However, coyotes may not be an important predator of sage-grouse. In a coyote prey base analysis, Johnson and Hansen (1979, p. 954) showed that sage-grouse and bird egg shells made up a very small percentage (0.4-2.4 percent) of analyzed scat samples. Additionally, coyote removal can have unintended consequences resulting in the release of mesopredators, many of which, like the red fox, may have greater negative impacts on sage-grouse (Mezquida
Greater sage-grouse are adapted to minimize predation by cryptic plumage and behavior. Because sage-grouse are prey, predation will continue to be an effect on the species. Where habitat is not limited and is of good quality, predation is not a threat to the persistence of the species. However, sage-grouse may be increasingly subject to levels of predation that would not normally occur in the historically contiguous unaltered sagebrush habitats. The impacts of predation on greater sage-grouse can increase where habitat quality has been compromised by anthropogenic activities (such as exurban development, road development) (e.g. Coates 2007, p. 154, 155; Bui 2009, p. 16; Hagen in press, p. 12). Landscape fragmentation, habitat degradation, and human populations have the potential to increase predator populations through increasing ease of securing prey and subsidizing food sources and nest or den substrate. Thus, otherwise suitable habitat may change into a habitat sink for grouse populations (Aldridge and Boyce 2007, p. 517). Anthropogenic influences on sagebrush habitats that increase suitability for ravens may limit sage-grouse populations (Bui 2009, p. 32). Current land-use practices in the intermountain West favor high predator (in particular, raven) abundance relative to historical numbers (Coates
The studies presented here suggest that, in areas of intensive habitat
The influence of synanthropic predators in southwestern Wyoming may be particularly significant as this area has one of the few remaining sagebrush landscapes and the most highly connected network of sage-grouse leks (Wisdom
Except in localized areas where habitat is compromised, we found no evidence to suggest predation is limiting greater sage-grouse populations. However, landscape fragmentation is likely contributing to increased predation on this species.
With regard to disease, the only concern is the potential effect of WNv. This disease is distributed throughout the species' range and affected sage-grouse populations experience high mortality rates (near 100 percent lethality), with resultant reductions in local population numbers. Risk of exposure varies with factors such as elevation, precipitation regimes, and temperature. The continued development of anthropogenic water sources throughout the range of the species, some of which are likely to provide suitable conditions for breeding mosquitoes that are part of the WNv cycle, will likely increase the prevalence of the virus in sage-grouse. We anticipate that WNv will persist within sage-grouse habitats indefinitely and may be exacerbated by factors (e.g., climate change) that increase ambient temperatures and the presence of the vector on the landscape. The occurrence of WNv occurrence is sporadic across the species' range, and a complex set of environmental and biotic conditions that support the WNv cycle must coincide for an outbreak to occur.
Where habitat is not limited and is of good quality, predation is not a significant threat to the species. We are concerned that continued landscape fragmentation will increase the effects of predation on this species, potentially resulting in a reduction in sage-grouse productivity and abundance in the future. However, there is very limited information on the extent to which such effects might be occurring. Studies of the effectiveness of predator control have failed to demonstrate an inverse relationship between the predator numbers and sage-grouse nesting success or population numbers, i.e., predator removal activities have not resulted in increased populations. Mortality due to nest predation by ravens or other human-subsidized predators is increasing in some areas, but there is no indication this is causing a significant rangewide decline in population trends. Based on the best scientific and commercial information available, we conclude that predation is not a significant threat to the species such that the species requires listing under the Act as threatened or endangered.
Under this factor, we examine whether threats to the greater sage-grouse are adequately addressed by existing regulatory mechanisms. Existing regulatory mechanisms that could provide some protection for greater sage-grouse include: (1) local land use laws, processes, and ordinances; (2) State laws and regulations; and (3) Federal laws and regulations. Regulatory mechanisms, if they exist, may preclude listing if such mechanisms are judged to adequately address the threat to the species such that listing is not warranted. Conversely, threats on the landscape are exacerbated when not addressed by existing regulatory mechanisms, or when the existing mechanisms are not adequate (or not adequately implemented or enforced).
Approximately 31 percent of the sagebrush habitats within the sage-grouse MZs are privately owned (Table 3; Knick in press, p. 39) and are subject only to local regulations unless Federal actions are associated with the property (e.g., wetland modification, Federal subsurface owner). We conducted extensive internet searches and contacted State and local working group contacts from across the range of the species to identify local regulations that may provide protection to the greater sage-grouse. We identified only one regulation at the local level that specifically addresses sage-grouse. Washington County, Idaho, Planning and Zoning has developed a draft Comprehensive Plan which states that “Sage Grouse leks...and a buffer around those leks, shall be protected from the disruption of development” (Washington County, 2009, p. 27). As this plan is still incomplete, and the final buffer distance has not been identified, it cannot currently provide the necessary regulatory provisions to be considered further. Sage-grouse were mentioned in other county and local plans across the range, and some general recommendations were made regarding effects to sage-grouse associated with land uses. However, we could find no other examples of county-planning and enforceable zoning regulations specific to sage-grouse.
State laws and regulations may impact sage-grouse conservation by providing specific authority for sage-grouse conservation over lands which are directly owned by the State; providing broad authority to regulate and protect wildlife on all lands within their borders; and providing a mechanism for indirect conservation through regulation of threats to the species (e.g. noxious weeds).
In general, States have broad authority to regulate and protect wildlife within their borders. All State wildlife agencies across the range of the species manage greater sage-grouse as resident native game birds except for Washington (Connelly
All States across the range of greater sage-grouse have laws and regulations
All of the states within the range of the sage-grouse have state school trust lands that they manage for income to support their schools. With the exception of Wyoming (see discussion below), none of the states have specific regulations to ensure that the management of the state trust lands is consistent with the needs of sage-grouse. Thus there are currently no regulatory mechanisms on state trust lands to ensure conservation of the species.
On September 26, 2008, the Governor of Nevada signed an executive order calling for the preservation and protection of sage-grouse habitat in the State of Nevada. The executive order directs the NDOW to “continue to work with state and federal agencies and the interested public” to implement the Nevada sage-grouse conservation plan. The executive order also directs other State agencies to coordinate with the NDOW in these efforts. Although directed specifically at sage-grouse conservation, the executive order is broadly worded and does not outline specific measures that will be undertaken to reduce threats and ensure conservation of sage-grouse in Nevada.
The California Environmental Quality Act (CEQA) (Public Resources Code sections 21000–21177), requires full disclosure of the potential environmental impacts of projects proposed in the State of California. Section 15065 of the CEQA guidelines requires a finding of significance if a project has the potential to “reduce the number or restrict the range of a rare or endangered plant or animal.” Under these guidelines sage-grouse are given the same protection as those species that are officially listed within the State. However, the lead agency for the proposed project has the discretion to decide whether to require mitigation for resource impacts, or to determine that other considerations, such as social or economic factors, make mitigation infeasible (CEQA section 21002). In the latter case, projects may be approved that cause significant environmental damage, such as destruction of endangered species, their habitat, or their continued existence. Therefore, protection of listed species through CEQA is dependent upon the discretion of the agency involved, and cannot be considered adequate protection for sage-grouse.
In Wyoming, the Governor issued an executive order on August 1, 2008, mandating special management for all State lands within sage-grouse “Core Population Areas” (State of Wyoming 2008, entire). Core Population Areas are important breeding areas for sage-grouse in Wyoming as identified by the Wyoming “Governor's Sage-Grouse Implementation Team.” In addition to identifying Core Population Areas, the Team also recommended stipulations that should be placed on development activities to ensure that existing habitat function is maintained within those areas. Accordingly, the executive order prescribes special consideration for sage-grouse, including authorization of new activities only when the project proponent can identify that the activity will not cause declines in greater sage-grouse populations, in the Core Population Areas. These protections will apply to slightly less than 23 percent of all sage-grouse habitats in Wyoming, but account for approximately 80 percent of the total estimated sage-grouse breeding population in the State. In February 2010, the Wyoming State Legislature adopted a joint resolution endorsing Wyoming's core area strategy as outlined in the Governor' Executive Order 2008-2.
On August 7, 2008, the Wyoming Board of Land Commissioners approved the application of the Implementation Team's recommended stipulations to all new development activities on State lands within the Core Population Areas. These actions provide substantial regulatory protection for sage-grouse in previously undeveloped areas on Wyoming State lands. However, as they only apply to State lands, which are typically single sections scattered across the State, the benefit to sage-grouse is limited.
The executive order also applies to all activities requiring permits from the Wyoming's Industrial Siting Council (ISC), including wind power developments on all lands regardless of ownership in the State of Wyoming. Developments outside of State land and not required to receive an ISC permit (primarily developments that do not reach a certain economic threshold) will not be required to follow the stipulations. The application of the Governor's order to the Wyoming ISC has the potential to provide significant regulatory protection for sage-grouse from adverse effects associated with wind development (see Energy, Factor A) and other developments.
There is still some uncertainty regarding what protective stipulations will be applied to wind siting applications. The State of Wyoming has indicated that it will enforce the Executive Order where applicable, and on August 7, 2009, the Wyoming State Board of Land Commissioners voted to withdraw approximately 400,000 ha (approximately 1 million ac) of land within the sage-grouse core areas from potential wind development (State of Wyoming 2008, entire). The withdrawal order states that “there is no published research on the specific impacts of wind energy on sage-grouse,” and further states that permitting for wind development should require data collection on the potential effects of wind on sage-grouse. This action demonstrates a significant action in the State of Wyoming to address future development activities in core areas.
Wyoming's executive order does allow oil and gas leases on State lands within core areas, provided those developments adhere to required protective stipulations, which are consistent with published literature (e.g. 1 well pad per section). The Service believes that the core area strategy proposed by the State of Wyoming in Executive Order 2008-2, if implemented by all landowners via -regulatory mechanisms, would provide adequate protection for sage-grouse and their habitat in that State.
The protective measures associated with the Governor's order do not extend to lands located outside the identified core areas but still within occupied sage-grouse habitat. Where a siting permit is needed, the application is
The Wyoming executive order states that current management and existing land uses within the core areas should be recognized and respected, thus we anticipate ongoing adverse effects
On April 22, 2009, the Governor of Colorado signed into law new rules for the Colorado Oil and Gas Conservation Commission (COGCC), which is the entity responsible for permitting oil and gas well development in Colorado (COGCC 2009, entire). The rules went into effect on private lands on April 1, 2009, and on Federal lands July 1, 2009. The new rules require that permittees and operators determine whether their proposed development location overlaps with “sensitive wildlife habitat,” or is within restricted surface occupancy (RSO) Area. For greater sage-grouse, areas within 1 km (0.6 mi) of an active lek are designated as RSOs, and surface area occupancy will be avoided except in cases of economic or technical infeasibility (CDOW, 2009, p. 12). Areas within approximately 6.4 km (4 mi) of an active lek are considered sensitive wildlife habitat (CDOW, 2009, p. 13) and the development proponent is required to consult with the CDOW to identify measures to (1) avoid impacts on wildlife resources, including sage-grouse; (2) minimize the extent and severity of those impacts that cannot be avoided; and (3) mitigate those effects that cannot be avoided or minimized (COGCC 2009, section 1202.a).
The COGCC will consider CDOW's recommendations in the permitting decision, although the final permitting and conditioning authority remains with COGCC. Section 1202.d of the new rules does identify circumstances under which the consultation with CDOW is not required; other categories for potential exemptions also can be found in the new rules (e.g., 1203.b). The new rules will inevitably provide for greater consideration of the conservation needs of the species, but the potential decisions, actions, and exemptions can vary with each situation, and consequently there is substantial uncertainty as to the level of protection that will be afforded to greater sage-grouse. It should be noted that leases that have already been approved but not drilled (e.g., COGCC 2009, 1202.d(1)), or drilling operations that are already on the landscape, may continue to operate without further restriction into the future.
Some States require landowners to control noxious weeds, a habitat threat to sage-grouse on their property, but the types of plants considered to be noxious weeds vary by State. For example, only Oregon, California, Colorado, Utah, and Nevada list
State-regulated hunting of sage-grouse is permitted in all States except Washington, where the season has been closed since 1988 (Connelly
Because it is not considered to be a migratory species, the greater sage-grouse is not covered by the provisions of the Migratory Bird Treaty Act (16 U.S.C. 703-712). However, several Federal agencies have other legal authorities and requirements for managing sage-grouse or their habitat. Federal agencies are responsible for managing approximately 64 percent of the sagebrush habitats within the sage-grouse MZs in the United States (Knick in press, p. 39, Table 3). Two Federal agencies with the largest land management authority for sagebrush habitats are the BLM and USFS. The U.S. Department of Defense (DOD), DOE, and other agencies in DOI have responsibility for lands and/or decisions that involve less than 5 percent of greater sage-grouse habitat (Table 3).
Knick (in press, p. 39, Table 3) estimates that about 51 percent of sagebrush habitat within the sage-grouse MZs is BLM-administered land; this includes approximately 24.9 million ha (about 61.5 million ac). The Federal Land Policy and Management Act of 1976 (FLPMA) (43 U.S.C. 1701
RMPs are the basis for all actions and authorizations involving BLM-administered lands and resources. They authorize and establish allowable resource uses, resource condition goals and objectives to be attained, program constraints, general management practices needed to attain the goals and objectives, general implementation sequences, intervals and standards for monitoring and evaluating RMPs to determine effectiveness, and the need for amendment or revision (43 CFR 1601.0-5(k)). The RMPs also provide a
Of the existing 92 RMPs that include sage-grouse habitat, 82 contain specific measures or direction pertinent to management of sage-grouse or their habitats (BLM 2008g, p. 1). However, the nature of these measures and direction vary widely, with some measures directed at a particular land use category (e.g., grazing management), and others relevant to specific habitat use categories (e.g., breeding habitat) (BLM 2008h). If an RMP contains specific direction regarding sage-grouse habitat, conservation, or management, it represents a regulatory mechanism that has the potential to ensure that the species and its habitats are protected during permitting and other decision-making on BLM lands. This section describes our understanding of how RMPs are currently implemented in relation to sage-grouse conservation.
In addition to land use planning, BLM uses Instruction Memoranda (IM) to provide instruction to district and field offices regarding specific resource issues. Implementation of IMs is required unless the IM provides discretion (Buckner 2009a. comm.). However, IMs are short duration (1 to 2 years) and are intended to immediately address resource concerns or provide direction to staff until a threat passes or the resource issue can be addressed in a long-term planning document. Because of their short duration, their utility and certainty as a long-term regulatory mechanism may be limited if not regularly renewed.
The BLM IM No. 2005-024 directed BLM State directors to “review all existing land use plans to determine the adequacy in addressing the threats to sage-grouse and sagebrush habitat,” and then to “identify and prioritize land use plan amendments or land use plan revisions based upon the outcome.” This IM instructed BLM State directors to develop a process and schedule to update deficient land use plans to adequately address sage-grouse and sagebrush conservation needs no later than April 1, 2005. The BLM reports that all land use plan revisions within sage-grouse habitat are scheduled for completion by 2015 (BLM, 2008g). To date, 14 plans have been revised, 31 are in progress, and 19 are scheduled to be completed in the future. However, the information provided to us by BLM did not specify what requirements, direction, measures, or guidance has been included in the newly revised RMPs to address threats to sage-grouse and sagebrush habitat. Therefore, we cannot assess their value or rely on them as regulatory mechanisms for the conservation of the greater sage-grouse.
On November 30, 2009, the BLM in Montana issued an IM that provides guidance for sage-grouse management on lands under their authority in MZs I and II (BLM 2009j, entire). The IM directs all state offices in Montana to develop alternatives in ongoing and future RMP revisions for activities that may affect the greater sage-grouse. The IM provides guidance to mitigate impacts and BMPs for all proposed projects and activities. While this IM will result in reduction of negative impacts of projects authorized by the Montana BLM on sage-grouse, the way in which the guidance will be interpreted and applied is uncertain and we do not have a basis to assess whether or the extent to which it might be effective in reducing threats. However, the IM is based on an approach based on core areas in Montana, similar to the approach implemented more formally in Wyoming. Therefore, it could be effective in reducing impacts to sage-grouse habitat in the short term on BLM lands in Montana. Unfortunately, the IM applies only to ongoing and future RMPs, and does not apply to activities authorized under existing RMPs. No expiration date was provided for this IM, but as discussed above typical life expectancy of IMs is rarely greater than 2 years.
The BLM has regulatory authority over livestock grazing, OHV travel and human disturbance, infrastructure development, fire management, and energy development through FLPMA and associated RMP implementation, and the Mineral Leasing Act (MLA) (30 U.S.C. 181
The rangeland health standards must address restoring, maintaining or enhancing habitats of BLM special status species to promote their conservation, and maintaining or promoting the physical and biological conditions to sustain native populations and communities (43 CFR 4180.2(e)(9) and (10)). BLM is required to take appropriate action no later than the start of the next grazing year upon determining that existing grazing practices or levels of grazing use are significant factors in failing to achieve the standards and conform with the guidelines (43 CFR 4180.2(c)).
The BLM conducted national data calls in 2004 through 2008 to collect information on the status of rangelands, rangeland health assessments, and measures that have been implemented to address rangeland health issues across sage-grouse habitats under their jurisdiction. However, the information collected by BLM could not be used to make broad generalizations about the status of rangelands and management actions. There was a lack of consistency across the range in how questions were interpreted and answered for the data call, which limited our ability to use the results to understand habitat conditions for sage-grouse on BLM lands. For example, one question asked about the number of acres of land within sage-grouse habitat that was meeting rangeland health standards. Field offices in more than three States conducted the rangeland health assessments, and reported landscape conditions at different scales (Sell 2009, pers. comm.). In addition, the BLM data call reported information at a different scale than was used for their landscape mapping (District or project level versus national scale) (Buckner 2009b, pers. comm.). Therefore, we lack the information necessary to assess how this regulatory mechanism effects sage-grouse conservation.
The BLM's regulations require that corrective action be taken to improve rangeland condition when the need is identified; however, actions are not necessarily implemented until the permit renewal process is initiated for the noncompliant parcel. Thus, there may be a lag time between the allotment
The BLM uses regulatory mechanisms to address invasive species concerns, particularly through the NEPA process. For projects proposed on BLM lands, BLM has the authority to identify and prescribe best management practices for weed management; where prescribed, these measures must be incorporated into project design and implementation. Some common best management practices for weed management may include surveying for noxious weeds, identifying problem areas, training contractors regarding noxious weed management and identification, providing cleaning stations for equipment, limiting off-road travel, and reclaiming disturbed lands immediately following ground disturbing activities, among other practices. The effectiveness of these measures is not documented.
The BLM conducts treatments for noxious and invasive weeds on BLM lands, the most common being reseeding through the Emergency Stabilization and Burned Area Rehabilitation Programs. According to BLM data, 66 of 92 RMPs noted that seed mix requirements (as stated in RMPs, emergency stabilization and rehabilitation, and other plans) were sufficient to provide suitable sage-grouse habitat (e.g., seed containing sagebrush and forb species)(Carlson 2008a). However, a sufficient seed mix does not assure that restoration goals will be met; many other factors (e.g., precipitation) influence the outcome of restoration efforts.
Invasive species control is a priority in many RMPs. For example, 76 of the RMPs identified in the data call claim that the RMP (or supplemental plans/guidance applicable to the RMP) requires treatment of noxious weeds on all disturbed surfaces to avoid weed infestations on BLM managed lands in the planning area (Carlson 2008a). Also, of the 82 RMPs that reference sage-grouse conservation, 51 of these specifically address fire, invasives, conifer encroachment, or a combination thereof (Carlson 2008, pers. comm.). We note that it is possible that more RMPs are addressing invasives under another general restoration category. In the 51 RMPs that address fire, invasives, and conifer encroachment, they typically provide nonspecific guidance on how to manage invasives. A few examples include: manage livestock in a way that enhances desirable vegetation cover and reduces the introduction of invasives, identify tools that may be used to control invasives (e.g., manual, mechanical, biological, or chemical treatments), utilize an integrated weed management program, and apply seasonal restrictions on fire hazards, among other methods (Carlson 2008, pers. comm.). As with other agencies and organizations, the extent to which these measures are implemented depends in large part on funding, staff time, and other regulatory and non-regulatory factors. Therefore, we cannot assess their value as regulatory mechanisms for the conservation of the greater sage-grouse.
Herbicides also are commonly used on BLM lands to control invasives. In 2007, the BLM completed a programmatic EIS (72 FR 35718) and record of decision (72 FR 57065) for vegetation treatments on BLM-administered lands in the western United States. This program guides the use of herbicides for field-level planning, but does not authorize any specific on-the-ground actions; site-specific NEPA analysis is still required at the project level.
The BLM has one documented regulatory action to address wildfire and protect of sage-grouse: National IM 2008-142 – 2008 Wildfire Season and Sage-Grouse Conservation. This IM was issued on June 19, 2008, and was effective through September 30, 2009. It provided guidance to BLM State directors that conservation of greater sage-grouse and sagebrush habitats should be a priority for wildfire suppression, particularly in areas of the Great Basin (portions of WAFWA MZ III, IV, and V) (BLM 2008j, entire). At least one BLM State office within the range of sage-grouse (Idaho) developed a State-level IM and guidance that prioritized the protection of sage-grouse habitats during fire management activities, in addition to the national IM which pertains to wildfire suppression activities (BLM 2008k, entire).
While we do not know the extent to which these directives alleviated the wildfire threat to sage-grouse (as described under Factor A) during the 2008 and 2009 fire seasons, we believe that this strategic approach to ameliorating the threat of fire is appropriate and significant. Targeting the protection of important sage-grouse habitats during fire suppression and fuels management activities could help reduce loss of key habitat due to fire if directed through a long-term, regulatory mechanism. Under Factor A, we describe why the threat of wildfire is likely to continue indefinitely. This foreseeable future requires a regulatory approach that addresses the threat over the long term. The use of IMs to increase protection of sage-grouse habitat during wildfire is not adequate to protect the species because IMs are both short-term and have discretionary renewal (decisions made on a case-by-case basis).
The BLM is the primary Federal agency managing the United States energy resources on 102 million surface ha (253 million ac) and 283 million sub-surface ha (700 million ac) of mineral estate (BLM 2010). Public sub-surface estate can be under public or private (i.e., split-estate) surface. Over 7.3 million ha (18 million ac) of sage-grouse habitats on public lands are leased for oil, gas, coal, minerals, or geothermal exploration and development across the sage-grouse range (Service 2008f). Energy development, particularly nonrenewable development, has primarily occurred within sage-grouse MZs I and II.
The BLM has the legal authority to regulate and condition oil and gas leases and permits under both FLPMA and the MLA. An amendment to the Energy Policy and Conservation Act of 1975 (42 U.S.C. 6201
On May 18, 2001, President Bush signed Executive Order (E.O.) 13212 – Actions to Expedite Energy-Related Projects (May 22, 2001, 66 FR 28357), which states that the executive departments and agencies shall take appropriate actions, to the extent consistent with applicable law, to expedite projects that will increase the production, transmission, or
Program-specific guidance for fluid minerals (including oil and gas) in the BLM planning handbook (BLM 2005b, Appendix C pp. 23-24) specifies that land use planning decisions will identify restrictions on areas subject to leasing, including closures, as well as lease stipulations. Stipulations are conditions that are made part of a lease when the environmental planning record demonstrates the need to accommodate various resources such as the protection of specific wildlife species. Stipulations advise the lease holder that a wildlife species in need of special management may be present in the area defined by the lease, and certain protective measures may be required in order to develop the mineral resource on that lease.
The handbook further specifies that all stipulations must have waiver, exception, or modification criteria documented in the plan, and notes that the least restrictive constraint to meet the resource protection objective should be used (BLM 2005b, Appendix C pp. 23-24). Waivers are permanent exemptions, and modifications are changes in the terms of the stipulation. The BLM reports the issuance of waivers and modifications as rare (BLM 2008i). Exceptions are a one-time exemption to a lease stipulation. For example, a company may be issued an exception to enter crucial winter habitat during a mild winter if an on-the-ground survey verifies that sage-grouse are not using the winter habitat or have left earlier than normal (BLM 2004, p. 86). In 2006 and 2007, of 1,716 mineral or right-of-way authorizations on Federal surface in 42 BLM planning areas no waivers were issued; 24 modifications were issued and 115 exceptions were granted, 72 of which were in the Great Divide planning area in Wyoming (BLM 2008i), one of the densest population concentrations for sage-grouse.
Although the restrictive stipulations that are applied to permits and leases vary, a 0.40-km (0.25-mi) radius around sage-grouse leks is generally restricted to “no surface occupancy” during the breeding season, and noise and development activities are often limited during the breeding season within a 0.80- to 3.22-km (0.5- to 2-mi) radius of sage-grouse leks. Although these are the most often-applied stipulations, site-specific application is highly variable. For example, language in the Randolph RMP in Utah states that no exploration, drilling, or other development activities can occur during the breeding season within 3.22 km (2 mi) of a known sage-grouse lek, and that there are “no exceptions to this stipulation” (BLM 2008h). Conversely, under the Platte River RMP in the Wind River Basin Management Area of Wyoming, “oil and gas development is a priority in the area” and “discretionary timing stipulations protecting sage-grouse nesting habitats...will not be applied” (BLM 2008h). Most of the RMPs that address oil, gas, or minerals development specify the standard protective stipulations (BLM 2008h). The stipulations do not apply to the operation or maintenance of existing facilities, regardless of their proximity to sage-grouse breeding areas (BLM 2008h). In addition, approximately 73 percent of leased lands in known sage-grouse breeding habitat have no stipulations at all (Service 2008f).
As noted above, a 0.4-km (0.25-mi) radius buffer is used routinely by BLM and other agencies to minimize the impacts of oil and gas development on sage-grouse breeding activity. The rationale for using a 0.4-km (0.25-mi) buffer as the basic unit for active lek protection is not clear, as there is no support in published literature for this distance affording any measure of protection (see also discussion under Energy Development, above). Anecdotally, this distance appears to be an artifact from the 1960s attempt to initiate planning guidelines for sagebrush management and is not scientifically based (Roberts 1991). The BLM stipulations most commonly attached to leases and permits are inadequate for the protection of sage-grouse, and for the long-term maintenance of their populations in those areas affected by oil and gas development activities (Holloran 2005, pp. 57-60; Walker 2007, p. 2651). In some locations, the BLM is incorporating recommendations and information from new scientific studies into management direction. Wyoming BLM issued an IM on December 29, 2009 (BLM 2009k, entire) to ensure their management of sage-grouse and their habitats are consistent with the State of Wyoming's core area populations (see discussion above). The IM applies to all BLM programs and activities within Wyoming, with the exception of livestock grazing management. A separate IM will be issued separately for this program. The December 2009 IM should have the same efficacy in ameliorating threats to the sage-grouse in Wyoming. However, the IM is scheduled to expire on Sept. 30, 2011, and therefore its life is far shorter than the foreseeable future (30 to 50 years, see discussion below) for energy development in that state. However, we are optimistic that this IM will result in short-term conservation benefits for sage-grouse in Wyoming.
As with fossil fuel sources, the production, purchase, and facilitation of development of renewable energy products by Federal entities and land management agencies is directed by the 2005 Energy Policy Act and Presidential E.O. 13212. The energy development section of Factor A describes in detail the development and operation of renewable energy projects, including recent increases in wind, solar and geothermal energy development. All of these activities require ground disturbance, infrastructure, and ongoing human activities that could adversely affect greater sage-grouse on the landscape. Recently the BLM has begun developing guidance to minimize impacts of renewable energy production on public lands. A ROD for “Implementation of a Wind Energy Development Program and Associated Land Use Plan Amendments” (BLM 2005a, entire) was issued in 2005. The ROD outlines best management practices (BMPs) for the siting, development and operation of wind energy facilities on BLM lands. The voluntary guidance of the BMPs do not include measures specifically intended to protect greater sage-grouse, although they do provide the flexibility for such measures to be required through site-specific planning and authorization (BLM 2005a, p. 2).
On December 19, 2008, the BLM issued IM 2009-043, which is intended to serve as additional guidance for processing wind development proposals. In that IM, which expires on September 30, 2010, BLM updates or clarifies previous guidance documentation, including the Wind Energy Development Policy, and best management practices from the wind energy development programmatic EIS of 2005. The new guidance does not
BLM State offices in Oregon and Idaho issued explicit guidance regarding siting of meteorological towers (IM OR-2008-014 and ID-2009-006, respectively) which required siting restrictions for towers around leks such that potential adverse effects to sage-grouse are avoided or minimized. These IMs provided substantial regulatory protection for sage-grouse; however, both of these IMs expired on September 30, 2009. We anticipate that they will be renewed in FY 2010, but that is an annual management decision by the respective State BLM offices, thus the long-term certainty that such measures will remain in place is unknown.
The BLM is currently in the process of developing programmatic-level guidance for the development of solar and geothermal energy projects. A draft programmatic EIS for geothermal development is currently available (BLM and USFS 2008a, entire), and the draft programmatic EIS for solar energy is under development (BLM and DOE 2008). We anticipate that solar and geothermal energy development will increase in the future (see discussion under energy in Factor A), and that the development of infrastructure associated with these projects could affect sage-grouse. Final environmental guidance for solar and geothermal energy development on BLM lands has not yet been issued or implemented; thus, we cannot assess its adequacy or implications for the conservation of sage-grouse.
The BLM manages the majority of greater sage-grouse habitats across the range of the species. The BLM has broad regulatory authority to plan and manage all land use activities on their lands including travel management, energy development, grazing, fire management, invasive species management, and a variety of other activities. As described in Factor A, all of these factors have the potential to affect sage-grouse, including direct effects to the species and its habitats. The ability of regulatory mechanisms to adequately address the effects associated with wildfire or invasive plant species such as
For other threats to sage-grouse on BLM lands, the BLM has the regulatory authority to address them in a manner that will provide protection for sage-grouse. However, BLM's current application of those authorities in some areas falls short of meeting the conservation needs of the species. This is particularly evident in the regulation of oil, gas, and other energy development activities, both on BLM-administered lands and on split-estate lands. Stipulations commonly applied by BLM to oil and gas leases and permits do not adequately address the scope of negative influences of development on sage-grouse (Holloran 2005, pp. 57-60, Walker 2007, pp. 2651; see discussion under Factor A), with the exception of the new 2010 IM issued by the BLM in Wyoming (see discussion below). In addition, BLM's ability to waive, modify, and allow exceptions to those stipulations without regard to sage-grouse persistence further limits the adequacy of those regulatory mechanisms in alleviating the negative impacts to the species associated with energy development.
For other threats, such as grazing, our ability to assess the application of existing regulatory mechanisms on a broad scale is limited by the way that BLM collected and summarized their data on rangeland health assessments and the implementation of corrective measures, where necessary. The land use planning and activity permitting processes, as well as other regulations available to BLM give them the authority to address the needs of sage-grouse. However, the extent to which they do so varies widely from RMP area to RMP area across the range of the species. In many areas existing mechanisms (or their implementation) on BLM lands and BLM-permitted actions do not adequately address the conservation needs of greater sage-grouse, and are exacerbating the effects of threats to the species described under Factor A.
The USFS has management authority for 8 percent of the sagebrush area within the sage-grouse MZs (Table 3; Knick in press, p. 39). The USFS estimated that sage-grouse occupy about 5.2 million ha (12.8 million ac) on national forest lands in the western United States (USFS 2008 Appendix 2, Table 1). Twenty-six of the 33 National Forests or Grasslands across the range of sage-grouse contain moderately or highly important seasonal habitat for sage-grouse (USFS 2008 Appendix 2, Table 2). Management of activities on national forest system lands is guided principally by the National Forest Management Act (NFMA) (16 U.S.C. 1600-1614, August 17, 1974, as amended 1976, 1978, 1980, 1981, 1983, 1985, 1988, and 1990). NFMA specifies that the USFS must have a land and resource management plan (LRMP) (16 U.S.C. 1600) to guide and set standards for all natural resource management activities on each National Forest or National Grassland. All of the LRMPs that currently guide the management of sage-grouse habitats on USFS lands were developed using the 1982 implementing regulations for land and resource management planning (1982 Rule, 36 CFR 219).
Greater sage-grouse is designated as sensitive species on USFS lands across the range of the species (USFS 2008, pp. 25-26). Designated sensitive species require special consideration during land use planning and activity implementation to ensure the viability of the species on USFS lands and to preclude any population declines that could lead to a Federal listing (USFS 2008, p. 21). Additionally, sensitive species designations require analysis for any activity that could have an adverse impact to the species, including analysis of the significance of any adverse impacts on the species, its habitat, and overall population viability (USFS 2008, p. 21). The specifics of how sensitive species status has conferred protection to sage-grouse on USFS lands varies significantly across the range, and is largely dependent on LRMPs and site-specific project analysis and implementation. Fourteen forests identify greater sage-grouse as a Management Indicator Species (USFS 2008, Appendix 2, Table 2), which requires them to establish objectives for the maintenance and improvement of habitat for the species during all planning processes, to the degree consistent with overall multiple use objectives of the alternative (1982 Rule,
Almost all of the habitats that support sage-grouse on USFS lands also are open to livestock grazing (USFS 2008, p. 39). Under the Range Rescissions Act of 1995 (P.L. 104-19), the USFS must conduct a NEPA analysis to determine whether grazing should be authorized on an allotment, and what resource protection provisions should be included as part of the authorization (USFS 2008, p. 33). The USFS reports that they use the sage-grouse habitat guidelines developed in Connelly
Energy development occurs on USFS lands, although to a lesser extent than on BLM lands. Through NFMA, LRMPs, and the On-Shore Oil and Gas Leasing Reform Act (1987; implementing regulations at 36 CFR 228, subpart E), the USFS has the authority to manage, restrict, or attach protective measures to mineral and other energy permits on USFS lands. Similar to BLM, existing protective standard stipulations on USFS lands include avoiding construction of new wells and facilities within 0.4 km (0.25 mi), and noise or activity disturbance within 3.2 km (2.0 mi) of active sage-grouse leks during the breeding season. As described both in Factor A and above, this buffer is inadequate to prevent adverse impacts to sage-grouse populations. For most LRMPs where energy development is occurring, these stipulations also apply to hard mineral extraction, wind development, and other energy development activities in addition to fluid mineral extraction (USFS 2008, Appendix 1, entire). The USFS is a partner agency with the BLM on the draft programmatic EIS for geothermal energy development described above. The Record of Decision for the EIS does not amend relevant LRMPs and still requires project-specific NEPA analysis of geothermal energy applications on USFS lands (BLM and USFS 2008b, p. 3).
The land use planning process and other regulations available to the USFS give it the authority to adequately address the needs of sage-grouse, although the extent to which they do so varies widely across the range of the species. We do not have information regarding the current land health status of USFS lands in relation to the conservation needs of greater sage-grouse; thus, we cannot assess whether existing conditions adequately meet the species' habitat needs.
Other Federal agencies in the DOD, DOE, and DOI (including the Bureau of Indian Affairs, the Service, and National Park Service) are responsible for managing less than 5 percent of sagebrush lands within the United States (Knick 2008, p. 31). Regulatory authorities and mechanisms relevant to these agencies' management jurisdictions include the National Park Service Organic Act (39 Stat. 535; 16 U.S.C. 1, 2, 3 and 4), the National Wildlife Refuge System Administration Act (16 U.S.C. 668dd-668ee), and the Department of the Army's Integrated Natural Resources Management Plans for their facilities within sage-grouse habitats. Due to the limited amount of land administered by these agencies, we have not described them in detail here. However, most of these agencies do not manage specifically for greater sage-grouse on their lands, except in localized areas (e.g., specific wildlife refuges, reservations). One exception is DOD regulatory mechanisms applicable within MZ VI, where half of the remaining sage-grouse populations and habitats occur on their lands.
The Yakima Training Center (YTC), a U.S. Army facility, manages land in Washington that is the primary habitat for one of two populations of greater sage-grouse in that State. During the breeding season, the YTC has restrictions on training activities for the protection of sage-grouse. Leks have a 1-km (0.6-mi) buffer where all training is excluded, and aircraft below 91.4 m (300 ft) are restricted from midnight to 9 am from March 1 to May 15 (Stinson
The USDA Farm Service Agency manages the Conservation Reserve Program (CRP) which pays landowners a rental fee to plant permanent vegetation on portions of their lands, taking them out of agricultural production (Schroeder and Vander Haegen in press, p. 4-5). These lands are put under contract, typically for a 10–year period (Walker 2009, pers. comm.). In some areas across the range of sage-grouse, and particularly in Washington (Schroeder and Vander Haegen in press, p. 21), CRP lands provide important habitat for the species (see Factor A discussion). Under the 2008 Farm Bill, several changes could reduce the protection that CRP lands afford sage-grouse. First, the total acreage that can be enrolled in the CRP program at any time has been reduced from 15.9 million ha (39.2 million ac) to 12.9 million ha (32 million ac) for 2010-2012 (USDA 2009a, p. 1). Second, no more than 25 percent of the agricultural lands in any county can now be enrolled under CRP contracts, although there are provisions to avoid this cap if permission is granted by the County government (Walker 2009, pers. comm.). Third, the 2008 Farm Bill authorized the BCAP, which provides financial assistance to agricultural producers to establish and produce eligible crops for the conversion to bioenergy products (USDA 2009b, p. 1). As CRP contracts expire, the BCAP program could result in greater incentives to take land out of CRP and put it into production for biofuels (Walker 2009, pers. comm.). All of these changes could affect the amount of land in CRP, and in turn the habitat value provided to greater sage-grouse. This change is of particular importance in Washington, where CRP lands have been out of production long enough to provide habitat for sage-grouse. Although the 2008 Farm Bill has been
Greater sage-grouse are federally protected in Canada as an endangered species under schedule 1 of the Species at Risk Act (SARA; Canada Gazette, Part III, Chapter 29, Volume 25, No. 3, 2002). Passed in 2002, SARA is similar to the ESA and allows for habitat regulations to protect sage-grouse (Aldridge and Brigham 2003, p. 31). The species is also listed as endangered at the provincial level in Alberta and Saskatchewan, and neither province allows harvest (Aldridge and Brigham 2003, p. 31). In Saskatchewan, sage-grouse are protected under the Wildlife Habitat Protection Act, which protects sage-grouse habitat from being sold or cultivated (Aldridge and Brigham 2003, p. 32). In addition, sage-grouse are listed as endangered under the Saskatchewan Wildlife Act, which restricts development within 500 m (1,640 ft) of leks and prohibits construction within 1,000 m (3,281 ft) of leks between March 15 and May 15 (Aldridge and Brigham 2003, p. 32). As stated above, these buffers are inadequate to protect sage-grouse from disturbance. In Alberta, individual birds are protected, but their habitat is not (Aldridge and Brigham 2003, p. 32). Thus, although there are some protections for the species in Canada, they are not sufficient to assure conservation of the species.
There are many non-regulatory conservation measures that may provide local habitat protections. Although they are non-regulatory in nature, they are here to acknowledge these programs. We have reviewed and taken into account efforts being made to protect the species, as required by the Act. Although some local conservation efforts have been implemented and are effective in small areas, they are neither individually nor collectively at a scale that is sufficient to ameliorate threats to the species or populations. Many other conservation efforts are being planned but there is substantial uncertainty as to whether, where, and when they will be implemented, and whether they will be effective; further, even if the efforts being planned or considered become implemented and are effective in the future, they are not a scale, either individually or collectively, to be sufficient to ameliorate the threats to the species.
Other partnerships and agencies have also implemented broader-scale conservation efforts. Cooperative Weed Management Areas (CWMAs) provide a voluntary approach to control invasive species across the range of sage-grouse. CWMAs are partnerships between Federal, State, and local agencies, tribes, individuals, and interested groups to manage both species designated by State agencies as noxious weeds, and invasive plants in a county or multi-county geographical area. As of 2005, Oregon, Nevada, Utah, and Colorado had between 75 and 89 percent of their States covered by CWMAs or county weed districts, while Washington, Idaho, Montana, and Wyoming had between 90 and 100 percent coverage. Coverage in North Dakota is between 50 and 74 percent, and South Dakota has less than 25 percent coverage (Center for Invasive Plant Management 2008). Because these CWMAs are voluntary partnerships we cannot be assured that they will be implemented nor can we predict their effectiveness.
The Natural Resources Conservation Service (NRCS) of the USDA provides farmers, ranchers, and other private landowners with technical assistance and financial resources to support various management and habitat restoration efforts. This includes helping farmers and ranchers maintain and improve wildlife habitat as part of larger management efforts, and developing technical information to assist NRCS field staff with sage-grouse considerations when working with private landowners. Because of the variable nature of the actions that can be taken and the species they may address, some may benefit greater sage-grouse, some may cause negative impacts (e.g., because they are aimed at creating habitat conditions for other species that are inconsistent with the needs of sage-grouse), or are neutral in their effects. In May 2008, Congress passed the Food, Conservation, and Energy Act of 2008 (2008 Farm Bill, P.L. 110-246). The Farm Bill maintains or extends various technical and funding support programs for landowners. All conservation programs under the Farm Bill are voluntary, unless binding contracts for conservation planning or restoration are completed.
In 2006, WAFWA published the “Greater Sage-Grouse Comprehensive Conservation Strategy” (Conservation Strategy; Stiver
All of the States in the extant range of the greater sage-grouse have finalized conservation or management plans for the species and its habitats. These plans focus on habitat and population concerns at a State level. The degree to which they consider and address mitigation for a variety of threats varies substantially. For example, some plans propose explicit strategies for minerals and energy issues (e.g., Montana) or wind energy development (e.g., Washington), and others more generally acknowledge potential issues with energy development but do not identify specific conservation measures (e.g., Nevada) (Stiver
The WDFW has designated sage-grouse habitat as a “priority habitat” which classifies it as a priority for conservation and management, and provides species and habitat information to interested parties for land use planning purposes (Schroeder
There are several non-regulatory conservation efforts that address impacts to the sage-grouse, mostly at a local scale (e.g. local working group plans, CCAA). Their voluntary nature is appreciated, but their implementation and effectiveness may be compromised as a result. We are encouraged by the number and scale of these efforts, but lacking data on exact locations, scale, and effectiveness, we do not know if threats to the greater sage-grouse will be ameliorated as a result. We strongly encourage implementation of the WAFWA Conservation Strategy as we believe its implementation could be effective in reducing threats to this species.
To our knowledge, no current local land use or development planning regulations provide adequate protection to sage-grouse from development or other harmful land uses. Development and fragmentation of private lands is a threat to greater sage-grouse (see discussion under Factor A), and current local regulations do not adequately address this threat.
Wyoming and Colorado have implemented State regulations regarding energy development that could provide significant protection for greater sage-grouse. In Wyoming, regulations regarding new energy development have the potential to provide adequate protection to greater sage-grouse by protecting core areas of the species' habitat. BLM Wyoming has adopted Wyoming's approach for projects under their authorities through a short-term IM. However, the restrictive regulations do not apply to existing leases, or to habitats outside of core areas. Thus, sage-grouse may continue to experience population-level impacts associated with activities (e.g., energy development) in Wyoming (see discussion under Factor A) both inside and outside core areas. In Colorado, the regulations describe a required process rather than a specific measure that can be evaluated; the regulations are only recently in place and their implementation and effectiveness remains to be seen.
The majority of sage-grouse habitat in the United States is managed by Federal agencies (Table 3). The BLM and USFS have the legal authority to regulate land use activities on their respective lands. Under Factor A, we describe the ways that oil, natural gas, and other energy development activities, fire, invasive species, grazing, and human disturbance are or may be adversely affecting sage-grouse populations and habitat. Overall, Federal agencies' abilities to adequately address the issues of wildfire and invasive species across the landscape, and particularly in the Great Basin, are limited. However, we believe that new mechanisms could be adopted to target the protection of sage-grouse habitats during wildfire suppression activities or fuels management projects, which could help reduce this threat in some situations. There is limited opportunity to implement and apply new regulatory mechanisms that would provide adequate protections or amelioration for the threat of invasive species. For grazing, the regulatory mechanisms available to the BLM and USFS are adequate to protect sage-grouse habitats; however, the application of these mechanisms varies widely across the landscape. In some areas, rangelands are not meeting the habitat standards necessary for sage-grouse, and that contributes to threats to the species.
Our assessment of the implementation of regulations and associated stipulations guiding energy development indicates that current measures do not adequately ameliorate impacts to sage-grouse. Energy and associated infrastructure development, including both nonrenewable and renewable energy resources, are expected to continue to expand in the foreseeable future. Unless protective measures consistent with new research findings are widely implemented via a regulatory process, those measures cannot be considered an adequate regulatory mechanism in the context of our review. For the BLM and USFS, RMPs and LRMPs are mechanisms through which adequate protections for greater sage-grouse could be implemented. However, the extent to which appropriate measures to conserve sage-grouse have been incorporated into those planning documents, or are being implemented, varies across the range. As evidenced by the discussion above, and the ongoing threats described under Factor A, BLM and the USFS are not fully implementing the regulatory mechanisms available to conserve greater sage-grouse on their lands.
Based on our review of the best scientific and commercial information available, we conclude that existing regulatory mechanisms are inadequate to protect the species. The absence of adequate regulatory mechanisms is a significant threat to the species, now and in the foreseeable future.
Few studies have examined the effects of pesticides to sage-grouse, but at least two have documented direct mortality of greater sage-grouse from use of these chemicals. Greater sage-grouse died as a result of ingestion of alfalfa sprayed with organophosphorus insecticides (Blus
Game birds that ingested sub-lethal levels of pesticides have been observed exhibiting abnormal behavior that may lead to a greater risk of predation (Dahlen and Haugen 1954, p. 477; McEwen and Brown 1966, p. 609; Blus
Cropland spraying may affect populations that are not adjacent to agricultural areas, given the distances traveled by females with broods from nesting areas to late brood-rearing areas (Knick
Much of the research related to pesticides that had either lethal or sub-lethal effects on greater sage-grouse was conducted on pesticides that have been banned or have their use further restricted for more than 20 years due to their toxic effects on the environment (e.g., dieldrin). We currently do not have any information to show that the banned pesticides are presently having negative impacts to sage-grouse populations through either illegal use or residues in the environment. For example, sage-grouse mortalities were documented in a study where they were exposed to strychnine bait used to control small mammals (Ward
Although a reduction in insect population levels resulting from insecticide application can potentially affect nesting sage-grouse females and chicks (Willis
Three approved insecticides, carbaryl, diflubenzuron, and malathion, are currently available for application across the extant range of sage-grouse as part of implementation of the Rangeland Grasshopper and Mormon Cricket Suppression Control Program, under the direction of the Animal and Plant Health Inspection Service (APHIS) (APHIS 2004, entire). Carbaryl is applied as bait, while diflubenzuron and malathion are sprayed. APHIS requires that application rates be in compliance with EPA regulations, and APHIS has general guidelines for buffer zones around sensitive species habitats. These pesticides are only applied for grasshopper and Mormon cricket (
In the Rangeland Grasshopper and Mormon Cricket Suppression Program Final Environmental Impact Statement—2002 (p.10), APHIS concluded that there “is little likelihood that the insecticide APHIS would use to suppress grasshoppers would be directly or indirectly toxic to sage-grouse. Treatments would typically not reduce the number of grasshoppers below levels that are present in non-outbreak years.” APHIS (2002, p. 69) stated that although “malathion is also an organophosphorus insecticide and carbaryl is a carbamate insecticide, malathion and carbaryl are much less toxic to birds” than other insecticides associated with effects to sage-grouse or other wildlife. The APHIS risk assessment (pp. 122-184) for this EIS determined that the grasshopper treatments would not directly affect sage-grouse. As to potential effects on prey abundance, APHIS noted that during “grasshopper outbreaks when grasshopper densities can be 60 or more per square meter (Norelius and Lockwood, 1999), grasshopper treatments that have a 90 to 95 percent mortality still leave a density of grasshoppers (3 to 6) that is generally greater than the average density found on rangeland, such as in Wyoming, in a normal year (Schell and Lockwood, 1997).”
Herbicide applications can kill sagebrush and forbs important as food sources for sage-grouse (Carr 1968 as cited in Call and Maser 1985, p. 14). The greatest impact resulting from a reduction of either forbs or insect populations is for nesting females and chicks due to the loss of potential protein sources that are critical for successful egg production and chick nutrition (Johnson and Boyce 1991, p. 90; Schroeder
In summary, pesticides can result in direct mortality of individuals, and also can reduce the availability of food sources, which in turn could contribute to mortality of sage-grouse. Despite the potential effects of pesticides, we could find no information to indicate that the use of these chemicals, at current levels, negatively affects greater sage-grouse population numbers. Schroeder
Greater sage-grouse exposure to various types of environmental contaminants may potentially occur as a result of agricultural and rangeland management practices, mining, energy development and pipeline operations, nuclear energy production and research, and transportation of materials along highways and railroads.
A single greater sage-grouse was found covered with oil and dead in a wastewater pit associated with an oil
Numerous gas and oil pipelines occur within the occupied range of several populations of the species. Exposure to oil or gas from pipeline spills or leaks could cause mortalities or morbidity to greater sage-grouse. Similarly, given the extensive network of highways and railroad lines that occur throughout the range of the greater sage-grouse, there is some potential for exposure to contaminants resulting from spills or leaks of hazardous materials being conveyed along these transportation corridors. We found no documented occurrences of impacts to greater sage-grouse from such spills, and we do not expect they are a significant source of mortality because these types of spills occur infrequently and involve only a small area that might be within the occupied range of the species.
Exposure of sage-grouse to radionuclides (radioactive atoms) has been documented at the DOE's Idaho National Engineering Laboratory in eastern Idaho. Although radionuclides were present in greater sage-grouse at this site, there were no apparent harmful effects to the population (Connelly and Markham 1983, pp. 175-176). There is one site in the range formerly occupied by the species (Nuclear Energy Institute 2004), and construction is scheduled to begin on a new nuclear power plant facility in 2009 in Elmore County, Idaho, near Boise (Nuclear Energy Institute 2008) in MZ IV. At this new facility and any other future facilities developed for nuclear power, if all provisions regulating nuclear energy development are followed, it is unlikely that there will be impacts to sage-grouse as a result of radionuclides or any other nuclear products.
Boyle and Samson (1985, pp. 110-112) determined that non-consumptive recreational activities can degrade wildlife resources, water, and the land by distributing refuse, disturbing and displacing wildlife, increasing animal mortality, and simplifying plant communities. Sage-grouse response to disturbance may be influenced by the type of activity, recreationist behavior, predictability of activity, frequency and magnitude, activity timing, and activity location (Knight and Cole 1995, p. 71). Examples of recreational activities in sage-grouse habitats include hiking, camping, pets, and off-highway vehicle (OHV) use. We have not located any published literature concerning measured direct effects of recreational activities on greater sage-grouse, but can infer potential impacts from studies on related species and from research on non-recreational activities. Baydack and Hein (1987, p. 537) reported displacement of male sharp-tailed grouse at leks from human presence, resulting in loss of reproductive opportunity during the disturbance period. Female sharp-tailed grouse were observed at undisturbed leks while absent from disturbed leks during the same time period (Baydack and Hein 1987, p. 537). Disturbance of incubating female sage-grouse could cause displacement from nests, increased predator risk, or loss of nests. However, disruption of sage-grouse during vulnerable periods at leks, or during nesting or early brood rearing could affect reproduction or survival (Baydack and Hein 1987, pp. 537-538).
Sage-grouse avoidance of activities associated with energy field development (e.g., Holloran 2005, pp. 43, 53, 58; Doherty
Indirect effects to sage-grouse from recreational activities include impacts to vegetation and soils, and facilitating the spread of invasive species. Payne
Recreational use of OHVs is one of the fastest-growing outdoor activities. In the western United States, greater than 27 percent of the human population used OHVs for recreational activities between 1999 and 2004 (Knick
We are unaware of scientific reports documenting direct mortality of greater sage-grouse through collision with off-
Given the continuing influx of people into the western United States (see discussion under Urbanization, Factor A; Leu and Hanser, in press, p. 4), which is contributed to in part by access to recreational opportunities on public lands, we anticipate effects from recreational activity will continue to increase. The foreseeable future for this effect spans for greater than 100 years, as we do not anticipate the desire for outdoor recreational activities will diminish.
Sage-grouse have comparatively low reproductive rates and high annual survival (Schroeder
Sage-grouse have one of the most polygamous mating systems observed among birds (Deibert 1995, p. 92). Asymmetrical mate selection (where only a few of the available members of one sex are selected as mates) should result in reduced effective population sizes (Deibert 1995, p. 92), meaning the actual amount of genetic material contributed to the next generation is smaller than predicted by the number of individuals present in the population. With only 10 to 15 percent of sage-grouse males breeding each year (Aldridge and Brigham 2003, p. 30), the genetic diversity of sage-grouse would be predicted to be low. However, in a recent survey of 16 greater sage-grouse populations, only the Columbia Basin population in Washington showed low genetic diversity, likely as a result of long-term population declines, habitat fragmentation, and population isolation (Benedict
Aldridge and Brigham (2003, p. 30) estimated that up to 5,000 individual sage-grouse may be necessary to maintain an effective population size of 500 birds. Their estimate was based on individual male breeding success, variation in reproductive success of males that do breed, and the death rate of juvenile birds. We were unable to find any other published estimates of minimal population sizes necessary to maintain genetic diversity and long-term population sustainability in sage-grouse. However, the minimum viable population size necessary to sustain the evolutionary potential of a species (retention of sufficient genetic material to avoid the effect of inbreeding depression or deleterious mutations) has been estimated as high as an adult population of 5,000 individuals (Traill
Drought is a common occurrence throughout the range of the greater sage-grouse (Braun 1998, p. 148) and is considered a universal ecological driver across the Great Plains (Knopf 1996, p.147). Infrequent, severe drought may cause local extinctions of annual forbs and grasses that have invaded stands of perennial species, and recolonization of these areas by native species may be slow (Tilman and El Haddi 1992, p. 263). Drought reduces vegetation cover (Milton
Sage-grouse populations declined during the 1930s period of drought (Patterson 1952, p. 68; Braun 1998, p. 148). Drought conditions in the late 1980s and early 1990s also coincided with a period when sage-grouse populations were at historically low levels (Connelly and Braun 1997, p. 8). From 1985 through 1995, the entire range of sage-grouse experienced severe drought (as defined by the Palmer Drought Severity Index) with the exceptions of north-central Colorado (MZ II) and southern Nevada (MZ III). During this time period drought was particularly prevalent in southwestern Wyoming, Idaho, central Washington and Oregon, and northwest Nevada (University of Nebraska 2008). Abnormally dry to severe drought conditions still persist in Nevada and western Utah (MZ III and IV), Idaho (MZ IV), northern California and central Oregon (MZ V), and southwest Wyoming (MZ II) (University of Nebraska 2008).
Aldridge
In summary, drought has been a consistent and natural part of the sagebrush-steppe ecosystem and there is no information to suggest that drought was a cause of persistent population declines of greater sage-grouse under historic conditions. However, drought impacts on the greater sage-grouse may be exacerbated when combined with other habitat impacts that reduce cover and food (Braun 1998, p. 148).
Numerous factors have caused sage-grouse mortality, and probably morbidity, such as pesticides, contaminants, as well as factors that contribute to direct and indirect disturbance to sage-grouse and sagebrush, such as recreational activities. Drought has been correlated with population declines in sage-grouse, but is only a limiting factor where habitats have been compromised. Although we anticipate use of pesticides, recreational activities, and fluctuating drought conditions to continue indefinitely, we did not find any evidence that these factors, either separately, or in combination are resulting in local or range-wide declines of greater sage-grouse. New information regarding minimum population sizes necessary to maintain the evolutionary potential of a species suggests that sage-grouse in some areas throughout their range may already be at population levels below that threshold. This is a result of habitat loss and modification (discussed under Factor A).
We have evaluated the best available scientific information on other natural or manmade factors affecting the species' continued existence and determined that this factor does not singularly pose a significant threat to the species now or in the foreseeable future.
As required by the Act, we have carefully examined the best scientific and commercial information available in relation to the five factors used to assess whether the greater sage-grouse is threatened or endangered throughout all or a significant portion of its range. We reviewed the petitions, information available in our files, other available published and unpublished information, and other information provided to us after our notice initiating a status review of the greater sage-grouse was published. We also consulted with recognized greater sage-grouse and sagebrush experts and other Federal and State agencies.
In our analysis of Factor A, we identified and evaluated the present or threatened destruction, modification, or curtailment of the habitat or range of the greater sage-grouse from various causes, including: habitat conversion for agriculture; urbanization; infrastructure (e.g., roads, powerlines, fences) in sagebrush habitats; fire; invasive plants; pinyon-juniper woodland encroachment; grazing; energy development; and climate change. All of these, individually and in combination, are contributing to the destruction, modification, or curtailment of the greater sage-grouse's habitat or range. Almost half of the sagebrush habitat estimated to have been present historically has been destroyed. The impact has been greatly compounded by the fragmented nature of this habitat loss, as fragmentation results in functional habitat loss for greater sage-grouse even when otherwise suitable habitat is still present. Although sagebrush habitats are increasingly being destroyed, modified, and fragmented for multiple reasons, the impact is especially great in relation to fire and invasive plants (and the interaction between them) in more westerly parts of the range, and energy development and related infrastructure in more easterly areas. In addition, direct loss of habitat and fragmentation is occurring due to agriculture, urbanization, and infrastructure such as roads and powerlines built in support of several activities. Some of these habitat losses due to these activities occurred many years ago, but they continue to have an impact due to the resulting fragmentation. Renewed interest in agricultural activities in areas previously defined as unsuitable for these activities, due to economic and technological incentives are likely to increase habitat loss and fragmentation from agricultural conversion. Encroachment of pinyon and juniper woodland into sagebrush is increasing and likely to continue in several areas, altering the structure and composition of habitat to the point that is it is greatly diminished or of no value to sage-grouse. While effects of livestock grazing must be assessed locally, the continued removal of sagebrush to increase forage directly fragments habitat, and indirectly provides for fragmentation through fencing and opportunities for invasive plant incursion. Habitat loss and fragmentation also is very likely to increase as a result of increased temperatures and changes in precipitation regimes associated with the effects of climate change; also, the impacts of fire and invasive plants likely already are, and will continue to be, exacerbated by the effects of climate change.
Sagebrush restoration techniques are limited and generally ineffective. Further, restoring full habitat function may not be possible in some areas because alteration of vegetation, nutrient cycles, topsoil, and cryptobiotic crusts have exceeded the point beyond which recovery to pre-disturbance conditions or conditions suitable to populations of greater sage-grouse, is possible.
The impacts to habitat are not uniform across the range; some areas have experienced less habitat loss than others, and some areas are at relatively lower risk than others for future habitat destruction or modification. Nevertheless, the destruction and modification of habitat has been substantial in many areas across the range of the species, it is ongoing, and it will continue or even increase in the future. Many current populations of greater sage-grouse already are relatively small and connectivity of habitat and populations has been severely diminished across much of the range; and further isolation is likely for several populations. Even the Wyoming Basin and the Great Basin area where Oregon, Nevada, and Idaho intersect, which are the two stronghold areas with relatively large amounts of contiguous sagebrush and sizeable populations of sage-grouse, are experiencing habitat destruction and modification (e.g. as a result of oil and gas development and other energy development in the Wyoming Basin) and this will continue in the future. Several recent studies have demonstrated that sagebrush area is one of the best landscape predictors of greater sage-grouse persistence. Continued habitat destruction and modification, compounded by fragmentation and diminished connectivity, will result in reduced abundance and further isolation of many populations over time, increasing their vulnerability to extinction. Overall, this increases the risk to the entire species across its range.
Therefore, based on our review of the best scientific and commercial information available, we find that the present or threatened destruction, modification, or curtailment of the habitat or range of the greater sage-grouse is a significant threat to the species now and in the foreseeable future.
During our review of the best scientific and commercial information
We found that while greater sage-grouse are subject to various diseases, the only disease of concern is West Nile virus. Outbreaks of WNv have resulted in disease-related mortality is local areas. Because greater sage-grouse have little or no resistance to this disease, the likelihood of mortality of affected individuals is extremely high. Currently the annual patchy distribution of the disease is resulting in minimal impacts except at local scales. We are concerned by the proliferation of water sources associated with various human activities, particularly water sources developed in association with coal bed methane and other types of energy development, as they provide potential breeding habitat for mosquitoes that can transmit WNv. We expect the prevalence of this disease is likely to increase across much of the species' range, but understand the long-term response of different populations is expected to vary markedly. Further, a complex set of conditions that support the WNv cycle must coincide for an outbreak to occur, and consequently although we expect further outbreaks will occur and may be more widespread, they likely will still be patchy and sporadic. We found that while greater sage-grouse are prey for numerous species, and that nest predation by ravens and other human-subsidized predators may be increasing and of potential concern in areas of human development, no information indicates that predation is having or is expected to have an overall adverse effect on the species. Therefore, at this time, we find that neither disease nor predation is a sufficiently significant threat to the greater sage-grouse now or in the foreseeable future that it requires listing under the Act as threatened or endangered based on this factor.
Our review of the adequacy of existing regulatory mechanisms included mechanisms in both Canada (less than 2 percent of the species' range) and the United States. Greater sage-grouse are federally protected in Canada as an endangered species under that country's Species at Risk Act. The species also is listed as endangered by the provinces of Alberta and Saskatchewan, and neither province allows harvest. In Alberta, individual birds are protected, but their habitat is not. The Saskatchewan Wildlife Act restricts development within 500 m (1,640 ft) of leks and prohibits construction within 1,000 m (3,281 ft) of leks from March 15 – May 15, but numerous studies have shown these buffers are inadequate to protect sage-grouse, particularly in nesting areas.
We found very few mechanisms in place at the level of local governments that provide, either directly or indirectly, protections to the greater sage-grouse or its habitat. The species receives some protection under laws of each of the States currently occupied by greater sage-grouse, including hunting regulations and various other direct and indirect mechanisms. However, in most states these provide little or no protection to greater sage-grouse habitat. Colorado recently implemented State regulations regarding oil and gas development, but they apply only to new developments and prescribe a process rather than specific measures that we can evaluate or rely on to provide protection related to the covered actions. In Wyoming, a Governor's Executive Order (E. O. 2008-2) outlines a strategic framework of core habitat areas that may provide the adequate scale of conservation needed over time to ensure the long-term conservation of greater sage-grouse in the state, but currently only the provisions for Wyoming State lands show promise as regulatory mechanisms, affecting only a small portion of the species' range in Wyoming.
The majority of greater sage-grouse habitat is on Federal land, particularly areas administered by the Bureau of Land Management, and to a lesser extent the U.S. Forest Service. We found a diverse network of laws and regulations that relate directly or indirectly to protections for the greater sage-grouse and its habitat on Federal lands, including BLM and FS lands. However, the extent to which the BLM and FS have adopted and adequately implemented appropriate measures to conserve the greater sage-grouse and its habitat varies widely across the range of the species. Regulatory mechanisms addressing the ongoing threats related to habitat destruction and modification, particularly as related to fire, invasive plants, and energy development, are not adequate. There are no known existing regulatory mechanisms currently in place at the local, State, national, or international level that effectively address climate-induced threats to greater sage-grouse habitat. In summary, based on our review of the best scientific information available, we conclude that the inadequacy of existing regulatory mechanisms is a significant threat to the greater sage-grouse now and in the foreseeable future.
We assessed the potential risks from other natural or manmade factors including pesticides, contaminants, recreational activities, life history traits, and drought. We did not find any evidence these factors, either separately or in combination, pose a risk to the species. Therefore, we find that other natural and manmade factors affecting the continued existence of the species do not threaten the greater sage-grouse now or in the foreseeable future.
The greater sage-grouse occurs across 11 western States and 2 Canadian provinces and is a sagebrush obligate. Although greater sage-grouse have a wide distribution, their numbers have been declining since consistent data collection techniques have been implemented. Recent local moderations in the decline of populations indicate a period of relative population stability, particularly since the mid-1990s. This trend information was one key basis for our decision in 2005 that listing the greater sage-grouse was not warranted. The population trends appear to have continued to be relatively stable. However, our understanding of the status of the species and the threats affecting it has changed substantially since our decision in 2005. In particular, numerous scientific papers and reports with new and highly relevant information have become available, particularly during the past year.
Although the declining population trends have moderated over the past several years, low population sizes and relative lack of any sign of recovery across numerous populations is troubling. Previously, fluctuations in sage-grouse populations were apparent over time (based on lek counts as an index). However, these have all but ceased for several years, suggesting
Overall, the range of the species is now characterized by numerous relatively small populations existing in a patchy mosaic of increasingly fragmented habitat, with diminished connectivity. Many areas lack sufficient unfragmented sagebrush habitats on a scale, and with the necessary ecological attributes (e.g., connectivity and landscape context), needed to address risks to population persistence and support robust populations. Relatively small and isolated populations are more vulnerable to further reduction over time, including increased risk of extinction due to stochastic events. Two strongholds of relatively contiguous sagebrush habitat (southwestern Wyoming and northern Nevada, southern Idaho, southeastern Oregon and northwestern Utah) with large populations which are considered strongholds for the species are also being impacted by direct habitat loss and fragmentation that will continue for the foreseeable future.
We have reviewed and taken into account efforts being made to protect the species, as required by the Act. Although some local conservation efforts have been implemented and are effective in small areas, they are neither individually nor collectively at a scale that is sufficient to ameliorate threats to the species or populations. Many other conservation efforts are being planned but there is substantial uncertainty as to whether, where, and when they will be implemented, and whether they will be effective.
We have carefully assessed the best scientific and commercial information available regarding the present and future threats to the greater sage-grouse. We have reviewed the petition, information available in our files, and other published and unpublished information, and consulted with recognized greater sage-grouse and sagebrush experts. We have reviewed and taken into account efforts being made to protect the species. On the basis of the best scientific and commercial information available, we find that listing the greater sage-grouse is warranted across its range. However, listing the species is precluded by higher priority listing actions at this time, as discussed in the
We have reviewed the available information to determine if the existing and foreseeable threats render the species at risk of extinction now such that issuing an emergency regulation temporarily listing the species as per section 4(b)(7) of the Act is warranted. We have determined that issuing an emergency regulation temporarily listing the greater sage-grouse is not warranted at this time (see discussion of listing priority, below). However, if at any time we determine that issuing an emergency regulation temporarily listing the species is warranted, we will initiate this action at that time.
As described in the Taxonomy section, above, we have reviewed the best scientific information available on the geographic distribution, morphology, behavior, and genetics of sage-grouse in relation to putative eastern and western subspecies of sage-grouse, as formally recognized by the AOU in 1957 (AOU 1957, p. 139). The AOU has not published a revised list of subspecies of birds since 1957, and has acknowledged that some of the subspecies probably cannot be validated by rigorous modern techniques (AOU 1998, p. xii). The Service previously made a finding that the eastern subspecies is not a valid taxon and thus is not a listable entity (69 FR 933, January 7, 2004,), and the Court dismissed a legal challenge to that finding (see Previous Federal Action, above). Thus the 12–month petition finding we are making here is limited to the petition to list the western subspecies.
To summarize the information presented in the Taxonomy section (above), our status review shows the following with regard to the putative western subspecies: (1) there is insufficient information to demonstrate that the petitioned western sage-grouse can be geographically differentiated from other greater sage-grouse throughout the range of the taxon; (2) there is insufficient information to demonstrate that morphological or behavioral aspects of the petitioned western subspecies are unique or provide any strong evidence to support taxonomic recognition of the subspecies; and (3) genetic evidence does not support recognition of the western sage-grouse as a subspecies. To be eligible for listing under the Act, an entity must fall within the Act's definition of a species, “*** any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature” (Act, section 3(16)). Based on our review of the best scientific information available, we conclude that the western subspecies is not a valid taxon, and consequently is not a listable entity under the Act. Therefore, we find that listing the western subspecies is not warranted.
We note that greater sage-grouse covered by the petition to list the putative western subspecies (except for those in the Bi-State area, which are covered by a separate finding, below) are encompassed by our finding that listing the greater sage-grouse rangewide is warranted but precluded (see above). Further, greater sage-grouse within the Columbia Basin of Washington were designated as warranted, but precluded for listing as a DPS of the western subspecies in 2001 (65 FR 51578, May 7, 2001). However, with our finding that the western subspecies is not a listable entity, we acknowledge that we must reevaluate the status of the Columbia Basin population as it relates to the greater sage-grouse; we will conduct this analysis as our priorities allow.
As described above we received two petitions to list the Bi-State (Mono Basin) area populations of greater sage-grouse as a Distinct Population Segment. Please see the section titled “Previous federal actions” for a detailed history and description of these petitions. In order to make a finding on these petitions, we must first determine whether the greater sage-grouse in the Bi-State area constitute a DPS, and if so, we must conduct the relevant analysis of the five factors that are the basis for making a listing determination.
Under section 4(a)(1) of the Act, we must determine whether any species is an endangered species or a threatened species because of any of the five threat factors identified in the Act. Section 3(16) of the Act defines “species” to include “any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature” (16 U.S.C.
Under our DPS Policy, we consider three elements in a decision regarding the status of a possible DPS as endangered or threatened under the Act. We apply them similarly for additions to the List of Endangered and Threatened Wildlife, reclassification, and removal from the List. They are: (1) Discreteness of the population segment in relation to the remainder of the taxon; (2) the significance of the population segment to the taxon to which it belongs; and (3) the population segment's conservation status in relation to the Act's standards for listing (whether the population segment is, when treated as if it were a species, endangered or threatened). Discreteness is evaluated based on specific criteria provided in the DPS Policy. If a population segment is considered discrete under the DPS Policy we must then consider whether the discrete segment is “significant” to the taxon to which it belongs. If we determine that a population segment is discrete and significant, we then evaluate it for endangered or threatened status based on the Act's standards. The DPS evaluation in this finding concerns the Bi-State (Mono Basin) area greater sage-grouse that we were petitioned to list as threatened or endangered, as stated above.
Under our DPS Policy, a population segment of a vertebrate species may be considered discrete if it satisfies either one of the following conditions: (1) It is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors (quantitative measures of genetic or morphological discontinuity may provide evidence of this separation); or
(2) it is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act.
Bi-State area greater sage-grouse are genetically unique compared with other populations of greater sage-grouse. Investigations using both mitochondrial DNA sequence data and data from nuclear microsatellites have demonstrated that Bi-State area greater sage-grouse contain a large number of unique haplotypes not found elsewhere within the range of the greater sage-grouse (Benedict
The Service's DPS Policy states that quantitative measures of genetic or morphological discontinuity may be used as evidence of the marked separation of a population from other populations of the same taxon. In the Bi-State area, the present genetic uniqueness is most likely a manifestation of prehistoric physical isolation. Based on the reported timeline (thousands to tens of thousands of years) (Benedict
Currently, no greater sage-grouse occur in the Virginia Range, having been extirpated several decades ago. The population in closest proximity to the Bi-State area occurs in the Pah Rah Range to the northeast of Reno, Nevada, and approximately 50 km (31 mi) to the north of the Bi-State area. The Pah Rah Range occurs immediately to the north of the Virginia Range and south of the Virginia Mountains. It is currently unknown if the small remnant population occurring in the Pah Rah Range aligns more closely with the Bi-State birds or the remainder of the greater sage-grouse. The range delineation occurs south of the Virginia Mountains in one of three locations: (1) the small population occurring in the Pah Rah Range, (2) the extirpated population historically occurring in the Virginia Range, or (3) the Pine Nut Mountains. Limited studies of behavioral differences between the Bi-State population and other populations have not demonstrated any gross differences that suggest behavioral barriers (Taylor and Young 2006, p. 39).
We conclude the Bi-State population of greater sage-grouse is markedly separate from other populations of the greater sage-grouse based on genetic data from mitochondrial DNA sequencing and from nuclear microsatellites. The Bi-State area greater sage-grouse contain a large number of unique haplotypes not found elsewhere within the range of the species. The present genetic uniqueness exhibited by Bi-State area greater sage-grouse occurred over thousands and perhaps tens of thousands of years (Benedict
The DPS Policy states that if a population segment is considered discrete under one or both of the discreteness criteria, its biological and ecological significance will then be considered in light of Congressional guidance that the authority to list DPSs be used “sparingly” while encouraging the conservation of genetic diversity. In carrying out this examination, the Service considers available scientific evidence of the DPS's importance to the taxon to which it belongs. As specified in the DPS Policy, this consideration of the significance may include, but is not limited to, the following: (1) persistence of the discrete population segment in an ecological setting unusual or unique to the taxon; (2) evidence that its loss would result in a significant gap in the range of the taxon; (3) evidence that it
(1) Persistence of the discrete population segment in an ecological setting unusual or unique to the taxon. The Bi-State area greater sage-grouse population occurs in the Mono province (Rowland
(2) Evidence that its loss would result in a significant gap in the range of the taxon. The estimated total extant range of greater sage-grouse is 668,412 km
(3) Evidence that it is the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historical range. Bi-State area greater sage-grouse are not the only surviving occurrence of the taxon and represent a small proportion of the total extant range of the species.
(4) Evidence that the discrete population segment differs markedly from other populations of the species in its genetic characteristics. Genetic analyses show the Bi-State area sage-grouse have a large number of unique haplotypes not found elsewhere in the range of the species (Benedict
On the basis of the discussion presented above, we conclude the Bi-State greater sage-grouse population meets the significance criterion of our DPS Policy.
Based on the best scientific and commercial data available, as described above, we find that under our DPS Policy, the Bi-State greater sage-grouse population is discrete and significant to the overall species. Because the Bi-State greater sage-grouse population is both discrete and significant, we find that it is a distinct population segment under our DPS Policy. We refer to this population segment as the Bi-State DPS of the greater sage-grouse.
Pursuant to the Act, as stated above, we announced our determination that the petitions to list the Bi-State area population of greater sage-grouse contained substantial information that the action may be warranted. Having found the Bi-State population qualifies as a DPS, we now must consider, based on the best available scientific and commercial data whether the DPS warrants listing. We have evaluated the conservation status of the Bi-State DPS of the greater sage-grouse in order to make that determination. Our analysis follows below.
Please see this section of the greater sage-grouse 12–month petition finding (GSG finding) above for life history information.
Please see this section of the GSG finding, above, for information on sage-grouse habitat.
The Bi-State DPS of the greater sage-grouse historically occurred throughout most of Mono, eastern Alpine, and northern Inyo Counties, California (Hall
In 2001, the State of Nevada sponsored development of the
Currently in the Bi-State area, sage-grouse leks occur in all of the delineated PMUs, with the greatest concentration of leks occurring in the Bodie and South Mono PMUs. Historically there were as many as 122 lek locations in the Bi-State area, although not all were active in any given year. This number is likely inflated due to observer and mapping error. The Nevada Department of Wildlife (NDOW) reports a total of 89 known leks in the Bi-State area (NDOW 2008, p. 7; NDOW 2009, unpublished data). Of these, approximately 39 are considered active and approximately 30 appear to be core leks or occupied annually.
Due to long-term and extensive survey efforts, it is unlikely that new leks will be found in the Nevada or California portions of the Pine Nut and Desert Creek–Fales PMUs or the Bodie and South Mono PMUs in California (Espinosa 2006b, pers. comm.; Gardner 2006, pers. comm.). It is possible that unknown leks exist in the Mount Grant PMU and the Nevada and California portions of the White Mountains PMU, as these PMUs are less accessible resulting in reduced survey effort (Espinosa 2006b, pers. comm.; Gardner 2006, pers. comm.).
Based on landownership, 46 percent of leks in the Bi-State area occur on Bureau of Land Management (BLM) lands, 25 percent occur on U.S. Forest Service (USFS) lands, 17 percent occur on private land, 7 percent occur on Los Angeles Department of Water and Power (LADWP) lands, 4 percent occur on Department of Defense (DOD) lands, and 1 percent occur on State of California lands (Espinosa 2006c, pers. comm.; Taylor 2006, pers. comm.). Of the 30-35 core leks in the Bi-State area, only 3 are known to occur on private lands.
In 2004, WAFWA conducted a partial population trend analysis for the Bi-State area (Connelly
In 2008, WAFWA conducted a similar trend analysis on these two populations using a different statistical method for the periods from 1965 to 2007, 1965 to 1985, and 1986 to 2007 (WAFWA 2008, Appendix D). The 2008 WAFWA analysis reports the trend for the North Mono Lake population, as measured by maximum male attendance at leks, was negative from 1965 to 2007 and 1965 to 1985 but variable from 1986 to 2007, and suggests an increasing trend beginning in about 2000. WAFWA's results for the South Mono Lake population suggest a negative trend from 1965 to 2007, a stable trend from 1965 to 1985, and a variable trend from 1986 to 2007, again suggesting a positive trend beginning around 2000. These two populations do not encompass the entire Bi-State area but do represent a large percentage of known leks. The two PMUs excluded from this analysis were the Pine Nut and White Mountains, which WAFWA delineates as separate populations that lacked sufficient data for analysis.
A new analysis by Garton
The CDFG and NDOW annually conduct greater sage-grouse lek counts in the California and Nevada portions, respectively, of the Bi-State area. These lek counts are used by the CDFG and NDOW to estimate greater sage-grouse populations for each PMU in the Bi-State area. Low and high population estimates are derived by combining a corrected number of males detected on a lek, an assumed sex ratio of two females to one male, and two lek detection rates (intended to capture the uncertainty associated with finding leks). The lek detection rates vary by PMU but range between 0.75 and 0.95.
Beginning in 2003, the CDFG and NDOW began using the same method to estimate population numbers, and consequently, the most comparable population estimates for the entire Bi-State area start in 2003. Prior to 2003, Nevada survey efforts varied from year to year, with no data for some years, and inconsistent survey methodology. The CDFG methods for estimating populations of greater sage-grouse in California were more consistent than NDOW's prior to 2003. However, using population estimates for greater sage-grouse derived before 2003 could lead to invalid and unjustified conclusions given the variation in the number of leks surveyed, survey methodology, and population estimation techniques between the NDOW and CDFG. Therefore, we are presenting population numbers from 2003 to 2009. Population estimates derived from spring lek counts are problematic due to unknown or uncontrollable biases such as the true ratio of females to males or the percentage of uncounted leks. We provide this information in order to place into context what we consider to be a reasonable range as to the extent of the population in the Bi-State area as well as to demonstrate the apparent variability in annual estimates over the short term. For reasons described above we caution against assigning too much certainty to these results.
Spring population estimates are presented in Tables 11 and 12 for the South Mono, Bodie, Mount Grant, and Desert Creek–Fales PMUs (CDFG 2009, unpublished data; NDOW 2009, unpublished data). They also include population estimates for the Nevada portion of the Pine Nut PMU (NDOW 2009, unpublished data). However, they do not include population estimates for the White Mountains PMU or the California portion of the Pine Nut PMU. Due to the difficulty in accessing the White Mountains PMU, no consistent surveys have been conducted and it appears that birds are not present in the California portion of the Pine Nut PMU (Gardner 2006, pers. comm.).
As shown in Table 12, Federal lands comprise the majority of the area within PMUs. Although other land ownership is small in comparison, these other lands contain important habitat for greater sage-grouse life cycle requirements. In particular, mesic areas that provide important brood rearing habitat are often on private lands.
Casazza
Female greater sage-grouse home range size ranged from 2.3 to 137.1 km
The data from more than 7,000 telemetry locations, representing the 145 individuals indicate movement between populations in the Bi-State area is limited. No birds caught within the White Mountains, South Mono, or Desert Creek–Fales PMUs made movements outside their respective PMUs of capture. Previously, the NDOW tracked a female greater sage-grouse radio-marked near Sweetwater Summit in the Nevada portion of the Desert Creek–Fales PMU to Big Flat in the northern portion of the Bodie PMU, suggesting possible interaction between these PMUs. Also, some birds caught in the Bodie PMU made seasonal movements on the order of 8 to 24 km (5 to 15 mi) east into Nevada and the adjacent Mount Grant PMU. Within the Bi-State area some known bird movements would be classified as migratory, but the majority of radio-marked individuals have not shown movements large enough to be characterized as migratory (Casazza
In association with Casazza
Also in association with Casazza
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations at 50 CFR part 424, set forth procedures for adding species to the federal Lists of Endangered and Threatened Wildlife and Plants. In making this finding, we summarize below information regarding the status and threats to the Bi-State DPS of the greater sage-grouse in relation to the five factors provided in section 4(a)(1) of the Act. Under section (4) of the Act, we may determine a species to be endangered or threatened on the basis of any of the following five factors: (A) Present or threatened destruction, modification, or curtailment of habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. We evaluated whether threats to the Bi-State area greater sage-grouse DPS may affect its survival. Our evaluation of threats is based on information provided in the petitions, available in our files, and other sources considered to be the best scientific and commercial information available including published and unpublished studies and reports.
Our understanding of the biology, ecology, and habitat associations of the Bi-State DPS of the greater sage-grouse, and the potential effects of perturbations such as disease, urbanization, and infrastructure development on this population, is based primarily on research conducted across the range of the entire greater sage-grouse species. The available information indicates that the members of the species have similar physiological and behavioral characteristics, and consequently similar habitat associations. We believe the potential effects of specific stressors on the Bi-State DPS of the greater sage-grouse are the same as those described in the GSG finding, above. To avoid redundancy, the descriptions of these effects are omitted below and further detail and citations may be found in the corresponding analysis in the GSG finding, above.
The range of the Bi-State DPS of the greater sage-grouse is roughly 3 percent of the area occupied by the entire greater sage-grouse species, and the relative impact of effects caused by specific threats may be greater at this smaller scale. We have considered these differences of scale in our analysis and our subsequent discussion is focused on the degree to which each threat influences the Bi-State DPS of the greater sage-grouse. Individual threats described within Factors A through E below are not all present across the entire Bi-State area. However, the influence of each threat on specific populations may influence the resiliency and redundancy of the entire Bi-State greater sage-grouse population.
Changing land uses have and continue to occur in the Bi-State area. Where traditional private land use was primarily farming and ranching operations, today, some of these lands are being sold and converted to low-density residential housing developments. About 8 percent of the land base in the Bi-State area is privately owned. A 2004 threat analysis recognized urban expansion as a risk to greater sage-grouse in the Pine Nut, Desert Creek–Fales, Bodie, and South Mono PMUs (Bi-State Plan 2004, pp. 24, 47, 88, 169). The CDFG reports that private lands have been sold and one parcel was recently developed on Burcham Flat within the Desert Creek–Fales PMU (CDFG 2006). Additionally, a planned subdivision of a 48 ha (120 ac) parcel that is in close proximity to the Burcham Flat lek, 1 of 3 remaining leks in the California portion of the Desert Creek–Fales PMU, is currently under review by the County of Mono, California. The subdivision would replace a single ranch operation with three private residences.
Sagehen (16.2 ha (40 ac)) and Gaspipe (16.2 ha (40 ac)) Meadows located in the South Mono PMU have recently been affected by development. Also, Sinnamon (~485 ha, ~1,200 ac) and Upper Summers Meadows (~1,214 ha; ~3,000 ac) located in the Bodie PMU are currently for sale (Taylor 2008, pers. comm.). Each of these private parcels is important to greater sage-grouse because of the summer brood-rearing habitat they provide (Taylor 2008, pers. comm.). The NDOW is concerned that the urbanization or the division of larger tracts of private lands into smaller ranchettes will adversely affect greater sage-grouse habitat in the Nevada portion of the Pine Nut and Desert Creek–Fales PMUs (NDOW 2006, p. 4). The NDOW reported that expansions of Minden, Gardnerville, and Carson City, Nevada, are encroaching into the Pine Nut Range (within the Pine Nut PMU) and that housing development in Smith Valley and near Wellington, Nevada, has fragmented and diminished greater sage-grouse habitats in the north portion of the Desert Creek–Fales PMU (NDOW 2006, p. 4).
Development of private lands is known to impact greater sage-grouse habitat (Connelly
When private lands adjacent to public lands are developed, there can be impacts to greater sage-grouse on the public lands. Approximately 89 percent of the land contained within the Bi-State area is federally managed land, primarily by the USFS and BLM. The BLM and USFS manage public lands under federal laws that provide for multiple-use management, which allows a number of actions that are either detrimental or beneficial to sage-grouse (Bi-State Plan 2004). The Bi-State Plan (2004, pp. 24, 88) reported within the Pine Nut and Bodie PMUs, habitat loss and fragmentation associated with land use change and development is not restricted to private lands. Rights-of-way (ROW) across public lands for roads, utility lines, sewage treatment plants, and other public purposes are frequently granted to support development activities on adjacent private parcels.
Based on location data from radio-marked birds in the Desert Creek–Fales, Bodie, and South Mono PMUs, greater sage-grouse home ranges consist of a
The Town of Mammoth Lakes, California, located in the southern extent of the Bi-State planning area recently adopted measures that will allow for more development on private lands (Town of Mammoth Lakes General Plan 2007). Increased indirect effects to greater sage-grouse habitat are expected due increases in the human population in the area.
The proposed expansion of the Mammoth Yosemite Airport is located in occupied greater sage-grouse habitat within the South Mono PMU. Approximately 1.6 ha (4 ac) of land immediately surrounding the airport is zoned for development. Also, the Federal Aviation Administration (FAA) recently resumed regional commercial air service at the Airport with two winter flights per day beginning in 2008 and potentially increasing to a maximum of eight winter flights per day by 2011 (FAA 2008, ES-1). The Mammoth Yosemite Airport formerly had regional commercial air service from 1970 to the mid-1990's (FAA 2008, p. 1-5), and it currently supports about 400 flights per month of primarily single-engine, private aircraft (Town of Mammoth Lakes 2005, p. 4-204). All greater sage-grouse in the Long Valley portion of the South Mono PMU occur in close proximity to the Airport and have been exposed to commercial air traffic in the past, and are currently exposed to private air traffic. Effects of reinstating commercial air service at the Mammoth Yosemite Airport on greater sage-grouse are unknown as the level of commercial flight traffic these birds may be exposed to is undetermined as is the impact this exposure will have on population dynamics.
The Benton Crossing landfill in Mono County is located north of Crowley Lake in Long Valley (South Mono PMU) on a site leased from the LADWP. Common ravens (
Development of private lands for housing and the associated infrastructure within the Bi-State area is resulting in the destruction and modification of habitat of the Bi-State area greater sage-grouse DPS. The threat of development is greatest in the Pine Nut, Desert Creek–Fales, and Bodie PMUs, where development is, and will likely continue to impact Bi-State area greater sage-grouse DPS use of specific seasonal sites. The small private holdings in the Bi-State area are typically associated with mesic meadow or spring habitats that play an important role in greater sage-grouse life history. Greater sage-grouse display strong site fidelity to traditional seasonal habitats and loss of specific sites can have pronounced population impacts. The influence of land development on the population dynamics of greater sage-grouse in the Bi-State area is greater than a simple measure of spatial extent. As noted above, resumption of commercial air service at the Mammoth Yosemite Airport, combined with the construction of an adjacent business park, will likely affect greater sage-grouse in the South Mono PMU through increasing aircraft and human activity in or near sage-grouse habitat.
Development of public and private lands for a variety of purposes, including residential homes and ROWs to support associated infrastructure can negatively affect sage-grouse and their habitat, and while these threats may not be universal, localized areas of impacts are anticipated. Based on the data available, direct and indirect effects of urbanization have exerted and will continue to exert a negative influence in specific portions of greater sage-grouse range in the Bi-State area. This is already especially apparent in the northern portion of the range of the Bi-State DPS of the greater sage-grouse, in the Pine Nut, Desert Creek–Fales, and Bodie PMUs (NDOW 2006, p. 4; Bi-State Plan 2004, pp. 24, 88).
Fences are considered a risk to greater sage-grouse in all Bi-State PMUs (Bi-State Plan 2004, pp. 54, 80, 120, 124, 169). As stated in the December 19, 2006, 90–day finding (71 FR 76058), the BLM Bishop Field Office reported increased greater sage-grouse mortality and decreased use of leks when fences were in close proximity. Known instances of collision, and the potential to fragment and degrade habitat quality by providing movement pathways and perching substrates for invasive species and predators have been cited.
Fences can also provide a valuable rangeland management tool. If properly sited and designed, fencing may ultimately improve habitat conditions for greater sage-grouse. Near several leks in the Long Valley area of the South Mono PMU, the BLM and LADWP are currently using “let down” fences as a means of managing cattle. This design utilizes permanent fence posts but allows the horizontal wire strands to be effectively removed (let down) during the greater sage-grouse breeding season or when cattle are not present. While this method does not ameliorate all negative aspects of fence presence such as perches for avian predators, it does reduce the likelihood of collisions. Currently, data on the total extent (length and distribution) of existing fences and the amount of new fences being constructed are not available for the Bi-State area.
Powerlines occur in all Bi-State PMUs and are a known threat to the greater sage-grouse, but the degree of effect varies by location. In the Pine Nut PMU, powerlines border the North Pine Nut lek complex on two sides (Bi-State Plan 2004, p. 28). An additional line segment to the northwest of this complex is currently undergoing review by the BLM Carson City District. If this additional line is approved, powerlines will surround the greater sage-grouse habitat in the area. Of the four leks considered active in the area, the distance between the leks and the powerlines ranges from approximately 1.2 to 2.9 km (0.74 to 1.8 mi). Additionally, one line currently bisects the relatively limited nesting habitat in
In the Desert Creek–Fales PMU, powerlines are one of several types of infrastructure development that impact greater sage-grouse through displacement and habitat fragmentation (Bi-State Plan 2004, p. 54). Recent declines in populations near Burcham and Wheeler Flats in the California portion of the Desert Creek–Fales PMU may be related to construction of powerlines and associated land use activities (Bi-State Plan 2004, p. 54). This area continues to see urban development which will likely require additional distribution lines. In the Bodie PMU, utility lines are a current and future threat that affects multiple sites (Bi-State Plan 2004, p. 81). In northern California, utility lines have a negative effect on lek attendance and strutting activity. Radio-tagged greater sage-grouse loss to avian predation increased as the distance to utility lines decreased (Bi-State Plan 2004, p. 81). Common ravens are a capable nest predator and often nest on power poles or are found in association with roads. The Bi-State Plan also identifies numerous small-distribution utility lines in the Bodie PMU that are likely negatively affecting greater sage-grouse. The plan references the expected development of new lines to service private property developments. The BLM Bishop Field Office reported reduced activity at one lek adjacent to a recently developed utility line and suggested this may have been influenced by the development (Bi-State Plan 2004, p. 81). Since 2004, however, numbers at this lek have rebounded. Currently, there are no high-voltage utility lines in the Bodie PMU, nor are there any designated corridors for this use in existing land use plans (Bi-State Plan 2004, p. 82).
A high-voltage powerline currently fragments the Mount Grant PMU from north to south, with two to three additional smaller distribution lines extending from Hawthorne, Nevada, west to the California border. The larger north–south trending powerline is sited in a corridor that was recently adopted as part of the West-wide Energy Corridor Programmatic EIS (BLM/USFS 2009), thus future development of this corridor is anticipated. There are two leks that likely represent a single complex in proximity to this line segment that have been sporadically active over recent years. Whether this variation in active use is due to the powerline is not clear. Additionally, there is strong potential for geothermal energy development in the Mount Grant PMU that will require additional distribution lines to tie into the existing electrical grid (see
The Bi-State Plan (2004, p. 169) mentions three transmission lines in the South Mono PMU that may be impacting birds in the area on a year round basis including three leks that are in proximity to existing utility lines. Future geothermal development may also result in expansion of transmission lines in the South Mono PMU (Bi-State Plan 2004, p. 169). Threats posed by powerlines to the White Mountains PMU are not currently imminent, although future development is possible.
An extensive road network occurs throughout the Bi-State area. The type of road varies from paved, multilane highways to rough jeep trails but the majority of road miles are unpaved, dirt two-track roads. Traffic volume varies significantly, as does individual population exposure. For a comprehensive discussion of the effects of roads on greater sage-grouse see
In the South Mono PMU, roads are recognized as a risk factor that affects greater sage-grouse habitat and populations (Bi-State Plan 2004, p. 169). A variety of roads in this area have access to many significant lek sites. In Long Valley, lek sites are accessible via well maintained gravel roads. Recreational use of these areas is high and road traffic is substantial. Two lek sites that were in close proximity (< 300 m (1,000 ft)) to Highway 120 are thought to be extirpated although the exact cause of extirpation is unknown. Roads in the White Mountains PMU may negatively impact greater sage-grouse populations and their habitats, and construction of new roads in this PMU will fragment occupied or potential habitat for the species (Bi-State Plan 2004, pp. 120, 124).
Although greater sage-grouse have been killed due to vehicle collisions in the Bi-State area (Wiechmann 2008, p. 3), the greater threat with respect to roads is their influence on predator movement, invasion by nonnative annual grasses, and human disturbance. Currently in the Bi-State area, all federal lands except those managed by the BLM's Carson City District Office have restrictions limiting vehicular travel to designated routes. The lands where these restrictions apply account for roughly 1.6 million ha (4 million ac) or 86 percent of the land base in the Bi-State area. Both the Inyo and Humboldt–Toiyabe National Forests have recently mapped existing roads and trails on Forest Lands in the Bi-State area as part of a USFS Travel Management planning effort including identification of designated routes (Inyo National Forest 2009; Humboldt–Toiyabe National Forest 2009). These planning efforts will most directly influence the South Mono, Desert Creek–Fales, and Mount Grant PMUs; however, the degree to which they will influence greater sage-grouse populations is unclear. While the planning effort of the Inyo National Forest has, and the planning effort of the Humboldt-Toiyabe National Forest will likely add many miles of unauthorized routes to the National Forest System, these routes have already been in use for decades and any future negative impacts will be the result of an increase in use of these routes.
Starting in 2005, the BLM's Bishop Field Office implemented seasonal closures of several roads in proximity to three lek complexes in the Long Valley area of the South Mono PMU during the spring breeding season as part of a greater sage-grouse management strategy (BLM 2005c, p. 3). The Field Office is also rehabilitating several miles of redundant routes to consolidate use and minimize habitat degradation and disturbance for these same lek complexes.
Existing fences, powerlines, and roads fragment and degrade greater sage-grouse habitat, and contribute to direct mortality through collisions. Additionally, new fences, powerlines, and roads increase predators and invasive plants that increase fire risk and or displace native sagebrush vegetation. In the Bi-State area, all of these linear features adversely affect each of the PMUs both directly and indirectly to varying degrees. However, we do not have consistent and comparable information on miles of existing or new fences, powerlines and roads, or densities of these features within PMUs for the Bi-State area as a whole. Wisdom
Lek counts suggest that greater sage-grouse populations in Long Valley, and to a lesser degree Bodie Hills, have been relatively stable over the past 15 years. The remaining populations in the Bi-State area appear considerably less stable. Research on adult and yearling survival suggests that annual survival is relatively low in the northern half of the Bi-State area (Farinha 2008, unpublished data). Annual survival was lowest in birds captured in association with the Wheeler and Burcham Flat leks in the California portion of the Desert Creek–Fales PMU, an area in very close proximity to Highway 395 and several transmission lines. Research conducted on nest success, however, shows an opposite trend from that of adult survival, with overall nest success relatively high in the northern half of the Bi-State area and lower in the southern half (Kolada 2007, p. 52). In Long Valley, where nest success was lowest, the combination of linear features (infrastructure) and an increased food source (Benton Crossing landfill) for avian predators may be influencing nest survival. Given current and future development (based on known energy resources), the Mount Grant, Desert Creek–Fales, Pine Nut, and South Mono PMUs are likely to be the most directly influenced by new powerlines and associated infrastructure.
Greater sage-grouse in the Bi-State area have been affected by roads and associated human disturbance for many years. The geographic extent, density, type, and frequency of disturbance have changed over time, and the impact has likely increased with the proliferation of off-highway vehicles. There are no indications that the increasing trend of these activities will diminish in the near future.
Mineral extraction has a long history throughout the Bi-State area. Currently, the PMUs with the greatest exposure are Bodie, Mount Grant, Pine Nut, and South Mono (Bi-State Plan 2004, pp. 89, 137, 178). Although mining represents a year round risk to greater sage-grouse, direct loss of key seasonal habitats or population disturbances during critical seasonal periods are of greatest impact. In the Bodie PMU, mining impacts to the ecological conditions were most pronounced in the late 1800's and early 1900's when as many as 10,000 people inhabited the area. The area is still open to mineral development, and exploration is likely to continue into the future (Bi-State Plan 2004, pp. 89–90). In the Bodie Hills, current mining operations are restricted to small-scale gold and silver exploration and sand and gravel extraction activities with limited impacts on greater sage-grouse (Bi-State Plan 2004, p. 90). An exploratory drilling operation is currently authorized in the Bodie Hills near the historic Paramount Mine, approximately 8 km (5 mi) north of Bodie, California. The proposed action may influence movement and use of important seasonal habitats near Big Flat. If subsequent development occurs, restricted use of or movement through this area will adversely influence connectivity between the Bodie and Mount Grant PMUs.
The Mount Grant and Pine Nut PMUs also have a long history of mining activity. Activity in the Mount Grant PMU has typically consisted of open pit mining. Two open pit mines exist, one of which is currently active. It is likely that mining will continue and may increase during periods when prices for precious metals are high, negatively effecting the sage-grouse populations in those areas. Mining in the Mount Grant PMU is largely concentrated around the Aurora historic mining district. This area contains the largest remaining lek in the PMU, which is located on private land. In the Pine Nut PMU, most mining activity is confined in woodland habitat but there is some overlap with sage-grouse habitats.
The effect of mining is not evenly distributed throughout the Bi-State area. It is greatest in the Mount Grant and Bodie PMUs where mining impacts to habitat may decrease the persistence of greater sage-grouse in the Mount Grant PMU Aurora lek complex area. This area represents a significant stronghold for the Mount Grant PMU and serves as a potential connection between breeding populations in the Bodie Hills to the west with breeding populations occurring further east in the Wassuk Range located on the eastern edge of the Mount Grant PMU. Further mineral extraction in either of these PMUs will negatively influence the spatial extent of the breeding population occurring in the Bodie Hills and the long term persistence of these populations.
Although energy development and the associated infrastructure was identified as a risk for greater sage-grouse occurring in the Bi-State area (Bi-State Plan 2004, pp. 30, 178), the risk assessment preceded the current heightened interest in renewable energy and underestimated the threats to the species. Several locations in the Bi-State area have suitable wind resources, but currently only the Pine Nut Mountains have active leases that overlap sage-grouse distribution. Approximately 3,696 ha (9,135 ac) have been leased from the BLM Carson City District and are being evaluated for wind development. The areas under lease are on the main ridgeline of the Pine Nut Mountains extending from Sunrise Pass near the Lyon and Douglas County line south to the Mount Siegel area. The area is a mix of shrub and woodland habitats containing year-round greater sage-grouse habitat. The ridgeline occurs between the north and south greater sage-grouse populations in the Pine Nut PMU. The area was recently designated as a renewable energy “wind zone” by Nevada Governor Jim Gibbons' Renewable Energy Transmission Access Advisory Committee (RETAAC; RETAAC 2007, Figure 2). Development of the Pine Nut area will have a significant impact on the connectivity within this small population and greatly restrict access to nesting and brooding habitat. Additional areas located in sage-grouse habitat may have suitable wind resources and could be developed in the future.
In the South Mono PMU there are two geothermal plants located on private land immediately east of U.S. 395 at
Within the Desert Creek–Fales PMU, about 2,071 ha (5,120 ac) on the north end of the Pine Grove Hills near Mount Etna are leased for geothermal development. The leases in this area are valid through 2017. Several locations within the Mount Grant PMU are also under current leases and several more areas are currently proposed for leasing. Based on location and vegetation community, two of the leased areas in the Mount Grant PMU are of great importance to sage-grouse. Four sections (1,035 ha, 2,560 ac) are leased approximately 1.6–4.8 km (1–3 mi) southeast of the confluence between Rough Creek and the East Walker River near the Lyon and Mineral County line on lands managed by the USFS. This area is considered year-round greater sage-grouse habitat with from one to three active leks in proximity. Additionally, approximately 13 sections (3,366 ha, 8,320 ac) are leased around the Aurora historic mining district near the Nevada and California border. Much of this area is dominated by pinyon–juniper woodlands, but at least three sections (776 ha, 1,920 ac) contain sagebrush communities and there is one known lek in close proximity. The leased sections within the Desert Creek–Fales and Mount Grant PMUs also fall within the boundary delineated for geothermal development proposed by RETAAC (RETAAC 2007, Figure 2).
The likelihood of renewable energy facility development in the Bi-State area is high. There is strong support for energy diversification in both Nevada and California, and the energy industry considers the available resources in the area to warrant investment (RETAAC 2007, p. 8). Greater sage-grouse habitat in the Pine Nut and Mount Grant PMUs will likely be most affected by facility and infrastructure development. Given this anticipated development, additional fragmentation and isolation as well as some degree of range contraction will occur that will significantly affect the Pine Nut and Mount Grant PMUs. Renewable energy development is not evenly distributed across the entire Bi-State area, but it will likely be a significant threat to populations in the Pine Nut and Mount Grant PMUs.
In the Bi-State area, all PMUs are subject to livestock grazing with the majority of “public” allotments allocated to cattle and sheep (Bi-State Plan 2004). Determining how grazing impacts greater sage-grouse habitat and populations is complicated. There are data to support both beneficial and detrimental aspects of grazing (Klebenow 1981, p. 122; Beck and Mitchell 2000, p. 993), suggesting that the risk of livestock grazing to greater sage-grouse is dependent on site-specific management.
Kolada (2007, p. 52) reports nest success of greater sage-grouse in the Bi-State area on average to be as high as any results reported across the range of the species. However, nest success is varied among PMUs, and residual grass cover did not appear to be as significant a factor to nest success as in other western U.S. locations. These findings suggest that grazing in the Bi-State area may not be strongly influencing this portion of the bird's life history.
Important mesic meadow sites are relatively limited outside of Long Valley and the South Mono PMU, especially north of Mono Lake (Bi-State Plan 2004, pp. 17, 65, 130). This limitation may influence greater sage-grouse population growth rates. Although most of the grazed lands in the Bi-State area are managed by the BLM and USFS under rangeland management practices and are guided by agency land use plans, much of the suitable mesic habitats are located on private lands. Given their private ownership assessing the condition of these sites is difficult and conditions are not well known. Although there are federal grazing allotments that are exhibiting adverse impacts from livestock grazing, such as the Churchill Allotment in the Pine Nut PMU (Axtell 2008, pers. comm.), most allotments in the Bi-State area are classified as being in fair to good condition (Axtell 2008, pers. comm.; Murphy 2008, pers. comm.; Nelson 2008, pers. comm.). We have no information indicating how allotment condition classifications used by the BLM and USFS correlate with greater sage-grouse population health.
Feral horses are present in the Bi-State area. Connelly
There are localized areas of habitat degradation attributable to grazing that indirectly and cumulatively affect greater sage-grouse. Overall population estimates, while variable from year-to-year, show no discernable trend attributable to grazing. The impact on ecosystems by different ungulate taxa may have a combined negative influence on greater sage-grouse habitats (Beever and Aldridge in press, p. 20). Cattle, horses, mule deer, and antelope each use the sagebrush ecosystem somewhat differently and the combination of multiple species may produce a different result than simply more of a single species. Greater sage-grouse habitat in the Pine Nut PMU, as well as limited portions of the Bodie PMU, is affected by grazing management practices and has a negative effect on sage-grouse in those areas. Overall, the available data do not provide evidence that grazing by domestic or feral animals is a major impact to habitat of greater sage-grouse throughout the entire Bi-State area. However, the loss or degradation of habitat due to grazing contributes to the risk of extirpation of some local populations, which in turn contributes to increased risk to the persistence of the Bi-State DPS.
As discussed above, in the GSG finding, changes in the fire ecology that result in an altered wildfire regime are a present and future risk in all PMUs in
Invasion by annual grasses (e.g.,
Within the Bi-State area, wildfire is a potential threat to greater sage-grouse habitat in all PMUs. To date few large landscape scale fires have occurred and we have not yet seen changes to the fire cycle (e.g., shorter) due to invasion by nonnative annual grasses. The BLM and USFS manage the area under what is essentially a full-suppression fire-fighting policy given adequate resources. Based on the available information, wildfire is not currently a significant threat to the Bi-State DPS of the greater sage-grouse. However, the future threat of wildfire, given the fragmented nature and small size of the populations within the DPS, would have a significant effect on the overall viability of the DPS based on its effects on the habitat in the Pine Nut PMU.
A variety of nonnative, invasive plant species are present in all PMUs that comprise the Bi-State area, with
Wisdom
Pinyon–juniper encroachment into sagebrush habitat is a threat occurring in the Bi-State area (USFS 1966, p. 22). Pinyon–juniper encroachment is occurring to some degree in all PMUs, with the greatest loss and fragmentation of important sagebrush habitat in the Pine Nut, Desert Creek–Fales, Mount Grant, and Bodie PMUs (Bi-State Plan 2004, pp. 20, 39, 96, 133, 137, 167). No data exist for the Bi-State area that quantify the amount of sagebrush habitat lost to encroachment, or that clearly demonstrate pinyon–juniper encroachment has caused greater sage-grouse populations to decline. However, land managers consider it a significant threat impacting habitat quality, quantity and connectivity and increasing the risk of avian predation to sage-grouse populations (Bi-State Plan 2004, pp. 20, 39, 96) and several previously occupied locations are thought to have been abandoned due to encroachment (Bi-State Plan 2004, pp. 20, 133). Management treatment of pinyon–juniper is feasible but is often constrained by competing resource values and cost. Several thinning projects have been completed in the Bi-State area, accounting for approximately 1,618 ha (4,000 ac) of woodland removed.
While the current occurrence of
Global climate change is expected to affect the Bi-State area (Lenihan
A warming trend in the mountains of western North America is expected to decrease snow pack, accelerate spring runoff, and reduce summer stream flows (Intergovernmental Panel on Climate Change (IPCC) 2007, p. 11). Specifically in the Sierra Nevada, March temperatures have warmed over the last 50 years resulting in more rain than snow precipitation, which translates into earlier snowmelt. This trend is likely to continue and accelerate into the future (Kapnick and Hall 2009, p. 11). This change in the type of precipitation and the timing of snow melt will influence reproductive success by altering the availability of understory vegetation and meadow habitats. Increased summer temperature is also expected to increase the frequency and intensity of wildfires. Westerling
While it is reasonable to assume the Bi-State area will experience vegetation changes, we do not know how climate change will ultimately effect this greater sage-grouse population. It is unlikely that the current extent of shrub habitat will remain unchanged, whether the shift is toward a grass or woodland dominated system is unknown. Either result will negatively affect greater sage-grouse in the area. Additionally, it is also reasonable to assume that changes in atmospheric carbon dioxide levels, temperature, precipitation, and timing of snowmelt, will act synergistically with other threats such as wildfire and invasive species to produce yet unknown but likely negative effects to greater sage-grouse habitat and populations in the Bi-State area.
Destruction and modification of greater sage-grouse habitat is occurring and will continue in the Bi-State area due to urbanization, infrastructure (e.g., fences, powerlines, and roads), mining, renewable energy development, grazing, wildfire, and invasive plant species. At the individual PMU level the impact and timing of these threats vary. The Pine-Nut PMU has the lowest number of individuals of all Bi-State area (approximately 89 to 107 in 2009) PMUs and is threatened by urbanization, grazing management, wildfire, invasive species, and energy development. The threats to habitat in this PMU are likely to continue in the future which may result in continued declines in the populations over the short term.
The Desert-Creek Fales PMU contains the greatest number of sage-grouse of all Bi-State PMUs in Nevada (approximately 512 to 575 in 2009). The most significant threats in this PMU are wildfire, invasive species (specifically conifer encroachment), urbanization, and fragmentation. Private lands purchase in California and pinyon-juniper forest removal in Nevada reduced some of the threats at two important locations within this PMU. However, a recent proposal for a land parcel subdivision in proximity to Burcham Flat, California, threatens nesting habitat and one of the two remaining leks in the area. The imminence of these threats varies, however, with urbanization and fragmentation being the most imminent threats to habitat in this PMU.
The Mount Grant PMU has an estimated population of 376 to 427 individuals based on 2009 surveys. Threats in this PMU include renewable energy development and mining associated infrastructure. Additional threats include infrastructure (fences, powerlines, and roads), conifer encroachment, fragmentation, and impacts to mesic habitat on private land from grazing and water table alterations. These threats currently fragment, and may in the future continue to fragment habitat in this PMU and reduce or eliminate connectivity to populations in the Bodie Hills PMU to the west.
The Bodie and South Mono PMUs are the core of greater sage-grouse populations in the Bi-State area, and have estimated populations of 829 to 927 and 906 to 1,012 individuals based on 2009 surveys, respectively. These two PMUs comprise approximately 65 percent of the total population in the Bi-State area. Future loss or conversion of limited brood rearing habitat on private lands in the Bodie PMU is a significant threat to the population. The threat of future wildfire and subsequent habitat loss of conversion to annual grassland is of great concern. Threats from existing and future infrastructure, grazing, mineral extraction, and conifer encroachment are also present but believed to have a relatively lower impact. The most significant threat in the South Mono PMU involves impacts associated with human activity in the forms of urbanization and recreation. Other threats in this PMU include existing and future infrastructure, mining activities, and wildfire, but pose a relatively lower risk to habitat and the DPS.
Information on threats in White Mountains PMU is limited. The area is
Predicting the impact of global climate change on sage-grouse populations is challenging due to the relatively small spatial extent of the Bi-State area. It is likely that vegetation communities will not remain static and the amount of sagebrush shrub habitat will decrease. Further, increased variation in drought cycles due to climate change will likely place additional stress on sage-grouse habitat and populations. While greater sage-grouse evolved with drought, drought has been correlated with population declines and shown to be a limiting factor to population growth in areas where habitats have been compromised.
Taken cumulatively, the habitat-based threats in all PMUs will likely act to fragment and isolate populations of the DPS in the Bi-State area. Over the short term (10 years) the persistence of the Pine Nut PMU is not likely. Populations occurring in the Desert Creek–Fales and Mount Grant PMUs are under significant pressure and continued threats to habitat will likely increase likelihood of extirpation. The Bodie and South Mono PMUs are larger and more stable and should continue to persist. While the South Mono PMU appears to be an isolated entity, the Bodie PMU interacts with the Mount Grant and the Desert Creek–Fales PMUs, and the continued loss of habitat in these other locations will likely influence the population dynamics and possibly the persistence of the breeding population occurring in the Bodie PMU. The White Mountain PMU is likely already an isolated population and does not currently or would in the future contribute to the South Mono PMU.
Therefore, based on our review of the best scientific and commercial data available, we conclude threats from the present or threatened destruction, modification, or curtailment of greater sage-grouse habitat or range are significant to the Bi-State DPS of the greater sage-grouse.
The only known assessment of hunting effects specific to the Bi-State area is an analysis conducted by Gibson (1998) for the Bodie Hills and Long Valley lek complexes. This assessment indicated that populations in the South Mono PMU (Long Valley area) were depressed by hunting from the late 1960's to 2000 but the Bodie Hills population was not. The results of Gibson (1998) influenced the CDFG management of the Long Valley population through the limitation of allocated hunting permits (Gardner 2008, pers. comm.).
Prior to 1983, California had no limit on hunting permits in the area which covers the Bodie Hills portion of the Bodie PMU (North Mono Hunt Area) and the Long Valley portion of the South Mono PMU (South Mono Hunt Area). In 1983, CDFG closed the hunting season (Bi-State Plan 2004, pp. 73–74); however, it was reopened in 1987 when CDFG instituted a permit system that resulted in limiting the number of permits (hundreds) issued annually. In 1998, the number of permits issued was significantly reduced (Bi-State Plan 2004, pp. 74–75; Gardner 2008, pers. comm.).
From 1998 to the present, the number of hunting permits issued by the CDFG has ranged from 10 to 35 per year for the North Mono and South Mono Hunt Areas (Bi-State Plan 2004, p. 173; CDFG 2008). In 2008, 25 single bird harvest permits were issued for the North Mono Hunt Area, and 35 single bird harvest permits were issued for the South Mono Hunt Area (CDFG 2008). Assuming all permits were filled, and comparing these estimated harvest levels to the low spring population estimates for the Bodie and South Mono PMUs for 2008, there was an estimated loss of about 4 percent for each population (25 of 573 and 35 of 838 for Bodie PMU and South Mono PMU, respectively). These harvest levels are within the harvest rate of 10 percent or less recommended by Connelly
Hunting (gun) has been closed in the Nevada portion of the Bi-State area since 1999 (NDOW 2006, p. 2). The falconry season in this area was closed in 2003 (Espinosa 2006b, pers. comm.). The Washoe Tribe has authority over hunting on tribal allotments in the Pine Nut PMU. There are anecdotal reports of harvest by Tribal members but currently the Washoe Tribe Hunting and Fishing Commission does not issue harvest permits for greater sage-grouse nor are historical harvest records available (J. Warpea 2009, pers. comm.).
Neither the CDFG nor NDOW had any information on poaching of greater sage-grouse or the accidental taking of this species by hunters pursuing other upland game birds with open seasons for the Bi-State area. Gibson (2001, p. 4) does mention that a low level of known poaching occurred in Long Valley. Hunting has suppressed some populations in the Bi-State area historically. Harvest has been estimated to be as much as 4 percent of the population in Bodie and South Mono PMUs. While this may be considered to be at levels considered compensatory and within harvest guidelines, in Long Valley it likely continues to impact population growth.
The CDFG and NDOW provide public direction to leks and guidelines to minimize viewing disturbance on a case-by-case basis. Overall, lek locations in the Bi-State area are well known and some are frequently visited. Disturbance is possible; however, we have no data to suggest that non-consumptive recreational uses of greater sage-grouse are impacting local populations in the Bi-State area (Gardner 2008, pers. comm.; Espinosa 2008, pers. comm.). We are not aware of any studies of lek viewing or other forms of non-consumptive recreational uses related to greater sage-grouse population trends. We have no information that this type of recreational activity is having a negative impact on local populations or contributing to declining population trends of greater sage-grouse in the Bi-State area.
Regarding possible effects from scientific studies of greater sage-grouse, in the past 5 years, approximately 200 greater sage-grouse have been captured and handled by researchers. Casazza
Overall in the Bi-State area hunting is limited to such a degree that it is not apparently restrictive to overall population growth. However, hunting was shown to limit the population of greater sage-grouse occurring within the South Mono PMU historically and even at its current reduced level still likely suppresses this population. While hunting in the Bodie PMU appears to be compensatory, given this PMU's connection with the neighboring and non-hunted Mount Grant PMU and the current declines apparent in the Mount Grant population, additional evaluation of this hunting across jurisdictional boundaries is warranted. We have no information indicating poaching, non-consumptive uses, or scientific use significantly impact Bi-State greater sage-grouse populations, either separately of collectively. Therefore, based on our review of the best scientific and commercial data available we find that overutilization for commercial, recreational, scientific, or educational purposes is not a significant threat to the Bi-State DPS of the greater sage-grouse.
West Nile virus (WNv) is the only identified disease that warrants concern for greater sage-grouse in the Bi-State area. Small populations, such as those in the Bi-State area, are at higher risk of extirpation due to their low numbers and the additive mortality WNv causes (see
Annual and spatial variations in temperature and precipitation influence WNv outbreaks. Much of the Bi-State area occurs at relatively high elevations with short summers, and these conditions likely limit the extent of mosquito and WNv occurrence, or at least may limit outbreaks to the years with above-average temperatures. The Bi-State area represents the highest known elevation at which greater sage-grouse have been infected with WNv, about 2,300 m (7,545 ft; Walker and Naugle
The extent that WNv influences greater sage-grouse population dynamics in the Bi-State area is uncertain, and barring a severe outbreak, natural variations in survival and reproductive rates that drive population growth may be masking the true impact of the disease. However, the dramatic fluctuations in recent lek counts in the Desert Creek–Fales and Mount Grant PMUs may indicate past outbreaks. Based on our current knowledge of the virus, the relatively high elevations and cold temperatures common in much of the Bi-State area likely reduce the chance of a population-wide outbreak. However, there may be localized areas of significant outbreaks that could influence individual populations. West Nile virus is a relatively new source of mortality for greater sage-grouse and to date has been limited in its impact in the Bi-State area. Although predicting precisely when and where further outbreaks will occur is not possible, the best scientific data available support a conclusion that outbreaks are very likely to continue to occur. However, the loss of individual populations from WNv outbreaks, which is particularly a risk for smaller populations, may influence the persistence of the Bi-State DPS through the loss of redundancy to the overall population and the associated challenges of recolonizing extirpated sites through natural emigration.
Range-wide, annual mortality of breeding-age greater sage-grouse varies from 55 to 75 percent for females and 38 to 60 percent for males, with the majority of mortality attributable to predation (Schroeder and Baydack 2001, p. 25). Although not delineated by sex, the best data available for the Bi-State population reports apparent annual adult mortality due to predation of between 58 and 64 percent (Casazza
Nest success across the Bi-State area is within the normal range, with some locations even higher than previously documented (Kolada 2007, p. 52). The lowest estimates occur in Long Valley (21 percent; Kolada 2007, p. 66). The low estimates in Long Valley are of concern as this population represents the stronghold for the species in the Bi-State area and is also the population most likely exposed to the greatest predation (Coates 2008, pers. comm.). Although significantly more birds were present in the past, the Long Valley population appears stable. The negative impact from reduced nesting success is presumably being offset by other demographic statistics such as high chick or adult survival.
We have a poor understanding of the effects of disease on Bi-State greater sage-grouse populations, and we are concerned about the potential threat, especially in light of recent documented presence of WNv and the potential impacts this disease can have on population growth. WNv is a substantial mortality factor for greater sage-grouse populations when outbreaks occur. We
As discussed in Factor D of the GSG finding above, existing regulatory mechanisms that could provide some protection for greater sage-grouse include: (1) local land use laws, processes, and ordinances; (2) State laws and regulations; and (3) Federal laws and regulations. Actions adopted by local groups, states, or federal entities that are discretionary, including conservation strategies and guidance, are not regulatory mechanisms.
Approximately 8 percent of the land in the Bi-State area is privately owned (Bi-State Plan 2004). We are not aware of any existing county or city ordinances that provide protection specifically for the greater sage-grouse or their habitats on private lands.
In the Bi-State area, greater sage-grouse are managed by two state wildlife agencies (NDOW and CDFG) as resident native game birds. The game bird classification allows the direct human taking of greater sage-grouse during hunting seasons authorized and conducted under state laws and regulations. Currently, harvest of greater sage-grouse is authorized in two hunt units in California, covering approximately the Long Valley and Bodie Hills populations (CDFG 2008). Greater sage-grouse hunting is prohibited in the Nevada portion of the Bi-State area, where the season has been closed since 1999 (Greater Sage-Grouse Conservation Plan for Nevada and Eastern California 2004, pp. 59-61).
Each State bases its hunting regulations on local population information and peer-reviewed scientific literature regarding the impacts of hunting on the greater sage-grouse. Hunting seasons or closures are reviewed annually, and States implement adaptive management based on harvest and population data (Espinosa 2008, pers. com.; Gardner 2008, pers. com.). Based on the best data available, we can not determine whether or how hunting mortality, is affecting the populations. Therefore, we do not have information to indicate how regulated hunting is affecting the DPS.
State agencies directly manage approximately 1 percent of the total landscape dominated by sagebrush in the Bi-State area, and various State laws and regulations identify the need to conserve wildlife habitat (Bi-State Plan 2004). Laws and regulations in both California and Nevada allow for acquisition of funding to acquire and conserve wildlife habitats, including land purchases and entering into easements with landowners. California recently purchased approximately 470 ha (1,160 ac) in the Desert Creek–Fales PMU largely for the conservation of greater sage-grouse (Taylor 2008, pers. com.). However, any acquisitions authorized are discretionary on the part of the agencies and cannot be considered an adequate mechanism that alleviates threats to the DPS or its habitat.
The Bi-State Plan (2004) represents more than 2 years of collaborative analysis by numerous local biologists, land managers, and land users who share a common concern for the greater sage-grouse occurring in western Nevada and eastern California. The intent of the plan was to identify factors that negatively affect greater sage-grouse populations in the Bi-State area as well as conservation measures likely to ameliorate these threats and maintain these populations. These efforts are in addition to current research and monitoring efforts conducted by the States. These voluntary recommended conservation measures are in various stages of development and depend on the cooperation and participation of interested parties and agencies. The Bi-State Plan does not include any prohibitions against actions that harm greater sage-grouse or their habitat. Since development of the Bi-State Plan, the NDOW has committed approximately $250,000 toward conservation efforts, some of which have been implemented while others are pending. Other support has come from various federal, state, and local agencies. For example, a partnership between the NDOW and the USFS resulted in a recently completed pinyon–juniper removal project in the Sweetwater Range in the Desert Creek–Fales PMU encompassing about 1,300 ha (3,200 ac) of important greater sage-grouse habitat (NDOW 2008, p. 24). Additional efforts are also being developed to target restoration of important nesting, brood rearing, and wintering habitat components across the Bi-State area. However, the Bi-State Plan is not a regulation and its implementation depends on voluntary efforts. Thus the Bi-State Plan can not be considered to be an adequate regulatory mechanism.
The California Environmental Quality Act (CEQA) (Public Resources Code sections 21000–21177), requires full disclosure of the potential environmental impacts of projects proposed by state and local agencies. The public agency with primary authority or jurisdiction over the project is responsible for conducting an environmental review of the project, and consulting with the other agencies concerned with the resources affected by the project. Section 15065 of the CEQA guidelines requires a finding of significance if a project has the potential to “reduce the number or restrict the range of a rare or endangered plant or animal.” Species that are eligible for listing as rare, threatened, or endangered but are not so listed are given the same protection as those species that are officially listed with the State. However, once significant effects are identified, the lead agency has the option to mitigate the effects through changes in the project, or decide that overriding considerations, such as social or economic considerations, make mitigation infeasible (CEQA section 21002). In the latter case, projects may be approved that cause significant environmental damage, such as destruction of endangered species, and their habitat. Protection of listed species through CEQA is dependent upon the
Federally owned and managed land make up the majority of the landscape within the DPS's range. For a comprehensive discussion and analysis of federal laws and regulations please see this section under Factor D of the GSG finding.
Approximately 50 percent of the land base in the Bi-State area occurs on lands managed by the BLM. As stated in the GSG finding, FLPMA is the primary federal law governing most land uses on BLM-administered lands. Under FLPMA, the BLM has authority over livestock grazing, recreation, OHV travel and human disturbance, infrastructure development, fire management, and either in combination with or under the MLA and other mineral and mining laws, energy development and mining on its lands. In Nevada and California, the BLM manages for many of these activities within their jurisdiction. In Nevada and California, the BLM has designated the greater sage-grouse a sensitive species. BLM's management of lands in the Bi-State area is conducted consistent with its management of its lands across the greater sage-grouse range. Therefore, we refer the reader to the GSG finding above for a detailed discussion and analysis BLM's management of sage-grouse habitat on its lands.
The USFS manages approximately 35 percent of the land base in the Bi-State area. As stated in the GSG finding, management of activities on lands under USFS jurisdiction is guided principally by NFMA through associated LRMPs for each forest unit. Under NFMA and other federal laws, the USFS has authority to regulate recreation, OHV travel and other human disturbance, livestock grazing, fire management, energy development, and mining on lands within its jurisdiction. Please see the GSG finding for general information and analysis. All of the LRMPs that currently guide the management of sage-grouse habitats on USFS lands were developed using the 1982 implementing regulations for land and resource management planning (1982 Rule, 36 CFR 219), including two existing USFS LRMPs (USFS 1986, 1988) within greater sage-grouse habitat in the Bi-State area.
The greater sage-grouse is designated as a USFS Sensitive Species in the Intermountain Region (R4) and Pacific Southwest Region (R5), which include the Humboldt–Toiyabe National Forest's Bridgeport Ranger District and the Inyo National Forest in the Bi-State area. The specifics of how sensitive species status has conferred protection to sage-grouse on USFS lands varies significantly across the range, and is largely dependent on LRMPs and site-specific project analysis and implementation. The Inyo National Forest identifies sage-grouse as a Management Indicator Species. This identification requires the USFS to establish objectives for the maintenance and improvement of habitat for the species during all planning processes, to the degree consistent with overall multiple use objectives (1982 rule, 36 CFR 219.19(a)).
As part of the USFS Travel Management planning effort, both the Humboldt-Toiyabe National Forest and the Inyo National Forest are revising road designations in their jurisdictions. The Humboldt-Toiyabe National Forest released its Draft Environmental Impact Statement in July, 2009. The Inyo National Forest completed and released its Final Environmental Impact Statement and Record of Decision in August 2009 for Motorized Travel Management. The ROD calls for the permanent prohibition on cross country travel off designated authorized roads. However, since this prohibition is not specific to sage-grouse habitat and we cannot assess how this will be enforced, we cannot consider the policy to be a regulatory mechanism that can protect the DPS.
Additional federally managed lands in the Bi-State area include the DOD Hawthorne Army Depot, which represents less than 1 percent of the total land base. However, these lands provide relatively high quality habitat (Nachlinger 2003, p. 38) and likely provide some of the best greater sage-grouse habitat remaining in the Mount Grant PMU because of the exclusion of livestock and the public (Bi-State Plan 2004, p. 149). There are no National Parks or National Wildlife Refuges in any of the PMUs in the Bi-State area, and we are unaware of any private lands in the area that are enrolled in the United States Department of Agriculture Conservation Reserve Program.
As described above, habitat destruction and modification in the Bi-State area is a threat to the DPS. Federal agencies' abilities to adequately address several issues such as wildfire, invasive species, and disease across the Bi-State area are limited. For other stressors such as grazing, the regulatory mechanisms in place could be adequate to protect sage-grouse habitats; however, the application of these mechanisms varies. In some locations rangelands are not meeting habitat standards necessary for sage-grouse persistence, however, overall population estimates, while variable from year-to-year, show no discernable trend attributable to grazing.
The statutes, regulations, and policies guiding renewable energy development and associated infrastructure development, and mineral extraction for the greater sage-grouse range-wide generally are implemented similarly in the Bi-State area as they are across the range of the greater sage-grouse, and it is our conclusion that this indicates that current measures do not ameliorate associated impacts to the DPS.
The existing state and federal regulatory mechanisms to protect greater sage-grouse in the Bi-State area afford sufficient discretion to decision makers as to render them inadequate to ameliorate threats to the Bi-State DPS. We do not suggest that all resource decisions impacting sage-grouse have failed to adequately address sage-grouse needs and in fact commend the individuals and agencies working in the Bi-State area. However, the flexibility built into the regulatory process greatly reduces the adequacy of these mechanisms. Because of this, the available regulatory mechanisms are not sufficiently reliable to provide for conservation of the species in light of the alternative resource demands. Therefore, after a review of the best scientific and commercial data available, we find that the existing regulatory mechanisms are inadequate to ameliorate the threats to the Bi-State DPS of the greater sage-grouse.
A variety of recreational activities are pursued across the Bi-State area, including traditional activities such as fishing, hiking, horseback riding, and camping as well as more recently popularized activities, such as off-road-vehicle travel and mountain biking. As discussed under
The Bi-State Plan (2004) discusses the risk associated with off-road vehicles in the Pine Nut and the Mount Grant PMUs (Bi-State Plan 2004, pp. 27, 137–138). Additionally, for the Bodie and South Mono PMUs, the Bi-State Plan (2004, pp. 91–92, 170–171) discusses off-road vehicles in the context of all
Potential disturbance caused by nonmotorized forms of recreation (fishing, camping, hiking, big game hunting, dog training) are most prevalent in the South Mono and Bodie PMUs. These PMUs are also exposed to tourism-associated activity centered around Mono Lake and the towns of Mammoth Lakes and Bodie. The exact amount of recreational activity or user days occurring in the area is not known, however, the number of people in the area is increasing annually (Nelson 2008, pers. comm.; Taylor 2008, pers. comm.). Additionally, with the recent reestablishment of commercial air service to the Mammoth Yosemite Airport during the winter, greater sage-grouse in the South Mono PMU will be exposed to more flights during leking and the early nesting season than previously experienced. The early nesting season (in addition to the already busy summer months) will present the most significant new overlap between birds and human activity in the area. Leu
We are unaware of instances where off-road vehicle (including snowmobile) activity precluded greater sage-grouse use, or affected survival in the Bi-State area. There are areas where concerns may arise though, especially in brood rearing and wintering habitats, which are extremely limited in the Bi-State area. For example, during heavy snow years, essentially the entire population of birds in Long Valley has congregated in a very small area (Gardner 2008, pers. comm.). Off-road vehicle or snowmobile use in occupied winter areas could displace them to less optimal habitats (Bi-State Plan 2004, p. 91). Given the likelihood of a continuing influx of people into Mono County, especially in proximity to Long Valley, with access to recreational opportunities on public lands, we anticipate effects from recreational activity will increase.
Greater sage-grouse have comparatively slower potential population growth rates than other species of grouse and display a high degree of site fidelity to seasonal habitats (see this section under Factor E in the GSG finding above for further discussion and analysis). While these natural history characteristics would not limit greater sage-grouse populations across large geographic scales under historical conditions of extensive habitat, they may contribute to local declines where humans alter habitats, or when natural mortality rates are high in small, isolated populations such as in the case of the Bi-State DPS.
Isolated populations are typically at greater risk of extinction due to genetic and demographic concerns such as inbreeding depression, loss of genetic diversity, and Allee effect (the difficulty of individuals finding one another), particularly where populations are small (Lande 1988, pp. 1456–1457; Stephens
We have concern regarding viability of populations within PMUs in the Bi-State area due to their small size (Table 12) and isolation from one another. Although there is disagreement among scientists and considerable uncertainty as to the population size adequate for long-term persistence of wildlife populations, there is agreement that population viability is more likely to be ensured viability if population sizes are in the thousands of individuals rather than hundreds (Allendorf and Ryman 2002, p. 76; Aldridge and Brigham 2003, p. 30; Reed 2005, p. 565; Traill
The Bi-State population of greater sage-grouse is small and both geographically and genetically isolated from the remainder of the greater sage-grouse distribution, which increases risk of genetic, demographic, stochastic events. To date, however, available genetic data suggest genetic diversity in the Bi-State area is as high as or higher than most other populations of greater sage-grouse occurring in the West (Oyler–McCance and Quinn in press, p. 18). Thus, we currently do not have clear indications that genetic factors such as inbreeding depression, hybridization, or loss of genetic diversity place this DPS at risk. However, recent genetic analysis shows that greater sage-grouse occupying the White Mountains display a unique allelic frequency in comparison to other populations in the Bi-State area suggesting greater isolation (Oyler–McCance 2009, pers. comm.). Additionally, recent field studies in the Parker Meadows area (a single isolated lek system located in the South Mono
In addition to the potential negative effects to small populations due to genetic considerations, small populations such as those found in the Bi-State area are at greater risk than larger populations from stochastic events, such as environmental catastrophes or random fluctuations in birth and death rates, as well disease epidemics, predation, fluctuations in habitat available, and various other factors (see Traill
Our analysis shows certain recreational activities have the potential to directly and indirectly affect sage-grouse and their habitats. However, based on the information available, it does not appear that current disturbances are occurring at such a scale that would adversely affect sage-grouse populations in the Bi-State area. While this determination is highly constrained by lack of data, populations in the South Mono PMU, which are arguably exposed to the greatest degree of recreational activity, appear relatively stable at present. When issues such as recreation and changes in habitat are considered in conjunction with other threats, it is likely that populations in the northern half of the Bi-State area will be extirpated. Reintroduction efforts involving greater sage-grouse have had very limited success elsewhere, and natural recolonization of these areas will be slow or impossible due to their isolation and the limited number of birds in surrounding PMUs, as well as the constraints inferred by the species' life history characteristics. Therefore, based on our evaluation of the best scientific and commercial data available, we find threats from other natural or manmade factors are significant to the Bi-State DPS of the greater sage-grouse.
We have carefully assessed the best scientific and commercial data available regarding the past, present, and future threats to the Bi-State DPS of the greater sage-grouse. We have reviewed the petition, information available in our files, and other published and unpublished information, and consulted with recognized greater sage-grouse and sagebrush experts.
Threats identified under Factors A, C, D, and E are a threat to the Bi-State DPS of the greater sage-grouse. These threats are exacerbated by the small population sizes, isolated nature, and limited availability of important seasonal habitats for many Bi-State area populations. The major threat is current and future destruction, modification, or curtailment of habitats in the Bi-State area due to urbanization, infrastructure, mining, energy development, grazing, invasive and exotic species, pinyon–juniper encroachment, recreation, wildfire, and the likely effects of climate change. Individually, any one of these threats appears unlikely to severely affect persistence across the entire Bi-State DPS of the greater sage-grouse. Cumulatively, however, these threats interact in such a way as to fragment and isolate, and will likely contribute to the loss of populations in the Pine Nut and Desert Creek-Fales PMUs and will result in a significant range contraction for the Bi-State DPS. The Bodie and South Mono PMUs currently comprise approximately 65 percent of the entire DPS and will likely become smaller but persist barring catastrophic events. In light of on-going threats, the northern extent of the Bi-State area including the Pine Nut, Desert Creek–Fales, and Mount Grant PMUs are and will be most at risk. We anticipate loss of populations and contraction of others which would leave them susceptible to extirpation from stochastic events, such as wildfire, drought, and disease.
While sport hunting is currently limited and within harvest guidelines, if hunting continues it may add to the overall decline of adult populations in the Bodie and South Mono PMUs. Overall in the Bi-State area hunting is limited to such a degree that it is not apparently restrictive to overall population growth. We have no information indicating poaching, non-consumptive uses, or scientific use significantly impact Bi-State greater sage-grouse populations. Therefore, we find that overutilization for commercial, recreational, scientific, or educational purposes is not a significant threat to the Bi-State area DPS.
West Nile virus is a threat to the greater sage-grouse, and its occurrence and impacts are likely underestimated due to lack of monitoring. While the impact of this disease is currently limited by ambient temperatures that do not allow consistent vector and virus maturation, predicted temperature increases associated with climate change may result in this threat becoming more consistently prevalent. Predation facilitated by habitat fragmentation due to infrastructure (fences, powerlines and roads) and other human activities may be altering natural population dynamics in localized areas such as Long Valley. We find that disease and predation are threats to the Bi-State area DPS, although the impact of these threats is relatively low and localized at this time compared to other threats.
An examination of regulatory mechanisms for both the Bi-State DPS of the greater sage-grouse and sagebrush habitats revealed that while some mechanisms exist, it appears that they are being implemented in a manner that is not consistent with our current understanding of the species' life history requirements, reaction to disturbances, and currently understood conservation needs. Therefore, we find the existing regulatory mechanisms are ineffective at ameliorating habitat-based threats. Furthermore, certain threats (disease, drought, fire) may not be able to be adequately addressed by existing regulatory mechanisms.
Our analysis under Factor E indicates the current level of recreational activities do not appear to be adversely affecting sage-grouse populations in the Bi-State area. Populations in the South Mono PMU, which are arguably exposed to the greatest degree of recreational activity, appear relatively stable at present.
The relatively low number of local populations of greater sage-grouse, their small size, and relative isolation is problematic. The Bi-State area is composed of approximately 35 active leks representing 4 to 8 individual populations. Research has shown fitness and population size are strongly correlated and smaller populations are more subject to environmental and demographic stochasticity. When coupled with mortality stressors related to human activity and significant fluctuations in annual population size, long-term persistence of small populations is always problematic.
Given the species' relatively low rate of growth and strong site fidelity, recovery and repopulation of extirpated areas will be slow and infrequent. Translocation of this species is difficult and to date has not been successful, and given the limited number of source individuals, translocation efforts, if needed, are unlikely.
Within 30 years it is likely that greater sage-grouse in the Bi-State area will only persist in one or two populations located in the South Mono PMU (Long Valley) and the Bodie Hills PMU. These populations will likely be isolated from one another and due to decreased
As required by the Act, we have reviewed and taken into account efforts being made to protect the greater sage-grouse in the Bi-State area. Although some local conservation efforts have been implemented and are effective in small areas, they are neither individually nor collectively at a scale that is sufficient to ameliorate threats to the DPS as a whole, or to local populations. Other conservation efforts are being planned but there is substantial uncertainty as to whether, where, and when they will be implemented, and whether they will be effective.
We have carefully assessed the best scientific and commercial information available regarding the present and future threats to the Bi-State DPS of the greater sage-grouse. We have reviewed the petitions, information available in our files, and other published and unpublished information, and consulted with recognized greater sage-grouse and sagebrush experts. We have considered and taken into account efforts being made to protect the species. On the basis of the best scientific and commercial information available, we find that listing of the Bi-State DPS of the greater sage-grouse is warranted across its range. However, listing this DPS is precluded by higher priority listing actions at this time, as discussed in the
We have reviewed the available information to determine if the existing and foreseeable threats render the Bi-State DPS of the greater sage-grouse at risk of extinction now such that issuing an emergency regulation temporarily listing the species as per section 4(b)(7) of the Act is warranted. We have determined that issuing an emergency regulation temporarily listing the Bi-State DPS is not warranted at this time (see discussion of listing priority for this DPS, below). However, if at any time we determine that issuing an emergency regulation temporarily listing the Bi-State DPS is warranted, we will initiate this action at that time.
Preclusion is a function of the listing priority of a species in relation to the resources that are available and competing demands for those resources. Thus, in any given fiscal year (FY), multiple factors dictate whether it will be possible to undertake work on a proposed listing regulation or whether promulgation of such a proposal is warranted but precluded by higher-priority listing actions.
The resources available for listing actions are determined through the annual Congressional appropriations process. The appropriation for the Listing Program is available to support work involving the following listing actions: proposed and final listing rules; 90–day and 12–month findings on petitions to add species to the Lists of Endangered and Threatened Wildlife and Plants (Lists) or to change the status of a species from threatened to endangered; annual determinations on prior “warranted but precluded” petition findings as required under section 4(b)(3)(C)(i) of the Act; critical habitat petition findings; proposed and final rules designating critical habitat; and litigation-related, administrative, and program-management functions (including preparing and allocating budgets, responding to Congressional and public inquiries, and conducting public outreach regarding listing and critical habitat). The work involved in preparing various listing documents can be extensive and may include, but is not limited to: gathering and assessing the best scientific and commercial data available and conducting analyses used as the basis for our decisions; writing and publishing documents; and obtaining, reviewing, and evaluating public comments and peer review comments on proposed rules and incorporating relevant information into final rules. The number of listing actions that we can undertake in a given year also is influenced by the complexity of those listing actions; that is, more complex actions generally are more costly. For example, during the past several years, the cost (excluding publication costs) for preparing a 12–month finding, without a proposed rule, has ranged from approximately $11,000 for one species with a restricted range and involving a relatively uncomplicated analysis, to $305,000 for another species that is wide-ranging and involved a complex analysis.
We cannot spend more than is appropriated for the Listing Program without violating the Anti-Deficiency Act (see 31 U.S.C. § 1341(a)(1)(A)). In addition, in FY 1998 and for each FY since then, Congress has placed a statutory cap on funds which may be expended for the Listing Program, equal to the amount expressly appropriated for that purpose in that fiscal year. This cap was designed to prevent funds appropriated for other functions under the Act (for example, recovery funds for removing species from the Lists), or for other Service programs, from being used for Listing Program actions (see House Report 105-163, 105
Recognizing that designation of critical habitat for species already listed would consume most of the overall Listing Program appropriation, Congress also put a critical habitat subcap in place in FY 2002, and has retained it each subsequent year to ensure that some funds are available for other work in the Listing Program: “The critical habitat designation subcap will ensure that some funding is available to address other listing activities” (House Report No. 107-103, 107
Thus, through the listing cap, the critical habitat subcap, and the amount of funds needed to address court-mandated critical habitat designations, Congress and the courts have, in effect, determined the amount of money available for other listing activities. Therefore, the funds in the listing cap, other than those needed to address court-mandated critical habitat for already-listed species, set the limits on our determinations of preclusion and expeditious progress.
Congress also recognized that the availability of resources was the key element in deciding, when making a 12–month petition finding, whether we would prepare and issue a listing proposal or instead make a “warranted but precluded” finding for a given species. The Conference Report accompanying Public Law 97-304, which established the current statutory deadlines for listing and the warranted-but-precluded finding requirements that are currently contained in the Act, states (in a discussion on 90–day petition findings that by its own terms also covers 12–month findings) that the
In FY 2010, expeditious progress is that amount of work that can be achieved with $10,471,000, which is the amount of money that Congress appropriated for the Listing Program (that is, the portion of the Listing Program funding not related to critical habitat designations for species that are already listed). However these funds are not enough to fully fund all our court-ordered and statutory listing actions in FY 2010, so we are using $1,114,417 of our critical habitat subcap funds in order to work on all of our required petition findings and listing determinations. This brings the total amount of funds we have for listing actions in FY 2010 to $11,585,417. Our process is to make our determinations of preclusion on a nationwide basis to ensure that the species most in need of listing will be addressed first and also because we allocate our listing budget on a nationwide basis. The $11,585,417 is being used to fund work in the following categories: compliance with court orders and court-approved settlement agreements requiring that petition findings or listing determinations be completed by a specific date; section 4 (of the Act) listing actions with absolute statutory deadlines; essential litigation-related, administrative, and listing program-management functions; and high-priority listing actions for some of our candidate species. In 2009, the responsibility for listing foreign species under the Act was transferred from the Division of Scientific Authority, International Affairs Program, to the Endangered Species Program. Starting in FY 2010, a portion of our funding is being used to work on the actions described above as they apply to listing actions for foreign species. This has the potential to further reduce funding available for domestic listing actions, although there are currently no foreign species issues included in our high priority listing actions at this time. The allocations for each specific listing action are identified in the Service's FY 2010 Allocation Table (part of our administrative record).
In FY 2007, we had more than 120 species with a Listing Priority Number (LPN) of 2, based on our September 21, 1983, guidance for assigning an LPN for each candidate species (48 FR 43098). Using this guidance, we assign each candidate an LPN of 1 to 12, depending on the magnitude of threats (high vs. moderate to low), immediacy of threats (imminent or nonimminent), and taxonomic status of the species (in order of priority: monotypic genus (a species that is the sole member of a genus); species; or part of a species (subspecies, DPS, or significant portion of the range)). The lower the listing priority number, the higher the listing priority (that is, a species with an LPN of 1 would have the highest listing priority).
Because of the large number of high-priority species, we further ranked the candidate species with an LPN of 2 by using the following extinction-risk type criteria: International Union for the Conservation of Nature and Natural Resources (IUCN) Red list status/rank, Heritage rank (provided by NatureServe), Heritage threat rank (provided by NatureServe), and species currently with fewer than 50 individuals, or 4 or fewer populations. Those species with the highest IUCN rank (critically endangered), the highest Heritage rank (G1), the highest Heritage threat rank (substantial, imminent threats), and currently with fewer than 50 individuals, or fewer than 4 populations, comprised a group of approximately 40 candidate species (“Top 40”). These 40 candidate species have had the highest priority to receive funding to work on a proposed listing determination. As we work on proposed and final listing rules for these 40 candidates, we are applying the ranking criteria to the next group of candidates with LPNs of 2 and 3 to determine the next set of highest priority candidate species. There currently are 56 candidate species with an LPN of 2 that have not received funding for preparation of proposed listing rules.
To be more efficient in our listing process, as we work on proposed rules for these species in the next several years, we are preparing multi-species proposals when appropriate, and these may include species with lower priority if they overlap geographically or face the same threats as a species with an LPN of 2. In addition, available staff resources also are a factor in determining high-priority species provided with funding. Finally, proposed rules for reclassification of threatened species to endangered are lower priority, since as listed species, they are already afforded the protection of the Act and implementing regulations.
We assigned the greater sage-grouse an LPN of 8 based on our finding that the species faces threats that are of moderate magnitude and are imminent. These threats include the present or threatened destruction, modification, or curtailment of its habitat, and the inadequacy of existing regulatory mechanisms to address such threats. Under the Service's LPN Guidance, the magnitude of threat is the first criterion we look at when establishing a listing priority. The guidance indicates that species with the highest magnitude of threat are those species facing the greatest threats to their continued existence. These species receive the highest listing priority. We consider the threats that the greater sage-grouse faces to be moderate in magnitude because the threats do not occur everywhere across the range of the species at this time, and where they are occurring, they are not of uniform intensity or of such magnitude that the species requires listing immediately to ensure its continued existence. Although many of the factors we analyzed (e.g, disease, fire, urbanization, invasive species) are present throughout the range, they are not to the level that they are causing a significant threat to greater sage-grouse in some areas. Other threats are of high magnitude in some areas but are of low magnitude or nonexistent in other areas such that overall across the species' range, they are of moderate magnitude. Examples of this include: oil and gas development, which is extensive in the eastern part of the range but limited in the western portion; pinyon-juniper encroachment, which is substantial in some parts of the west but is of less concern in Wyoming and Montana; and agricultural development which is extensive in the Columbia Basin, Snake River Plain, and eastern Montana, but more limited elsewhere. While sage-grouse habitat has been lost or altered in many portions of the species' range, substantial habitat still remains to support the species in many areas of its range (Connelly
We also lack data on the actual future location of where some potential threats will occur (e.g., wind energy development exact location, location of the next wildfire). If these threats occur within unoccupied habitat, the magnitude of the threat to greater sage-grouse is greatly reduced. The likelihood that some occupied habitat will not be affected by threats in the foreseeable future leads us to consider the magnitude of threats to the greater sage-grouse as moderate. This likelihood is evidenced by our expectation that two strongholds of contiguous habitat will still remain in fifty years even though the threats discussed above will continue there.
Under our LPN Guidance, the second criterion we consider in assigning a listing priority is the immediacy of threats. This criterion is intended to ensure that the species facing actual, identifiable threats are given priority over those for which threats are only potential or that are intrinsically vulnerable but are not known to be presently facing such threats. We consider the threats imminent because we have factual information that the threats are identifiable and that the species is currently facing them in many portions of its range. These actual, identifiable threats are covered in great detail in factor A of this finding and include habitat fragmentation from agricultural activities, urbanization, increased fire frequency, invasive plants, and energy development.
The third criterion in our LPN guidance is intended to devote resources to those species representing highly distinctive or isolated gene pools as reflected by taxonomy. The greater sage-grouse is a valid taxon at the species level, and therefore receives a higher priority than subspecies or DPSs, but a lower priority than species in a monotypic genus.
We will continue to monitor the threats to the greater sage-grouse, and the species' status on an annual basis, and should the magnitude or the imminence of the threats change, we will re-visit our assessment of LPN.
Because we assigned the greater sage-grouse an LPN of 8, work on a proposed listing determination for the greater sage-grouse is precluded by work on higher priority candidate species (i.e., entities with LPN of 7 or lower); listing actions with absolute statutory, court ordered, or court-approved deadlines; and final listing determinations for those species that were proposed for listing with funds from FY 2009. This work includes all the actions listed in the tables below under expeditious progress (see Tables 13 and 14).
We also have assigned a listing priority number to the Bi-State DPS of the greater sage-grouse. As described above, under the Service's LPN Guidance, the magnitude of threat is the first criterion we look at when establishing a listing priority. The guidance indicates that species with the highest magnitude of threat are those species facing the greatest threats to their continued existence. These species receive a higher listing priority. Many of the threats to the Bi-State DPS that we analyzed are present throughout the range and currently impact the DPS to varying degrees (e.g. urbanization, invasive grasses, habitat fragmentation from existing infrastructure), and will continue into the future. The northern extent of the Bi-State area including the Pine Nut, Desert Creek–Fales, and Mount Grant PMUs are now and will continue to be most at risk. We anticipate loss of some local populations, and contraction of the range of others which would leave them susceptible to extirpation from stochastic events, such as wildfire, drought, and disease. Occupied habitat will continue to be affected by threats in the future and we expect that only two isolated populations in the Bodie and South Mono PMUs may remain in thirty years. The threats that are of high magnitude include: the present or threatened destruction, modification or curtailment of its habitat and range; the inadequacy of existing regulatory mechanisms; and other natural or manmade factors affecting the DPS's continued existence, such as the small size of the DPS (in terms of both the number of individual populations and their size) which increases the risk of extinction, particularly for the smaller local populations. Also the small number and size and isolation of the populations may magnify the impact of the other threats. We consider disease and predation to be relatively low magnitude threats compared to other existing threats.
The Bi-State DPS of the greater sage-grouse is composed of approximately 35 active leks representing 4 to 8 individual local populations, based on current information on genetics and connectivity. While some of the threats do not occur everywhere across the range of the DPS at this time (e.g. habitat-based impacts from wildfire, WNv infections), where threats are occurring, the risk they pose to the DPS may be exacerbated and magnified due to the small number and size and isolation of local populations within the DPS. We acknowledge that we lack data on the precise future location of where some impacts will manifest on the landscape (e.g., effects of climate change, location of the next wildfire). To the extent to which these impacts occur within unoccupied habitat, the magnitude of the threat to the Bi-State DPS is reduced. However, to the extent these impacts occur within habitat used by greater sage-grouse, due to the low number of populations and small size of most of them, the effects to the DPS may be greatly magnified. Due to the scope and scale of the high magnitude threats and current and anticipated future loss of habitat and isolation of already small populations, leads us to determine that the magnitude of threats to the Bi-State DPS of the greater sage-grouse is high.
Under our LPN Guidance, the second criterion we consider in assigning a listing priority is the immediacy of threats. This criterion is intended to ensure that the species facing actual, identifiable threats are given priority over those for which threats are only potential or that are intrinsically vulnerable but are not known to be presently facing such threats. We have factual information the threats imminent because we have factual information that the threats are identifiable and that the DPS is currently facing them in many areas of its range. In particular these actual, identifiable threats are covered in great detail in factor A of this finding and include habitat fragmentation and destruction due to urbanization, infrastructure (e.g. fences, powerlines, and roads), mining, energy development, grazing, invasive and exotic species, pinyon–juniper encroachment, recreation, and wildfire. Therefore, based on our LPN Policy the threats are imminent (ongoing).
The third criterion in our LPN guidance is intended to devote resources to those species representing highly distinctive or isolated gene pools as reflected by taxonomy. We have determined the Bi-State greater sage-grouse population to be a valid DPS according to our DPS Policy. Therefore under our LPN guidance, the Bi-State DPS of the greater sage-grouse is assigned a lower priority than a species in a monotypic genus or a full species that faces the same magnitude and imminence of threats.
Therefore, we assigned the Bi-State DPS of the greater sage-grouse an LPN of 3 based on our determination that the DPS faces threats that are overall of high magnitude and are imminent (i.e. ongoing). We will continue to monitor the threats to the Bi-State DPS of the greater sage-grouse, and the DPS' status
Because we assigned the Bi-State DPS of the greater sage-grouse an LPN of 3, work on a proposed listing determination for this DPS is precluded by work on higher priority candidate species (i.e., entities with LPN of 2 or lower); listing actions with absolute statutory, court ordered, or court-approved deadlines; and completion of listing determinations for those species for which work already has been initiated but is not yet completed. This work includes all the actions listed in the tables below under expeditious progress (see Tables 13 and 14).
As explained above, a determination that listing is warranted but precluded also must demonstrate that expeditious progress is being made to add or remove qualified species to and from the Lists of Endangered and Threatened Wildlife and Plants. (Although we do not discuss it in detail here, we also are making expeditious progress in removing species from the list under the Recovery Program, which is funded by a separate line item in the budget of the Endangered Species Program. As explained above in our description of the statutory cap on Listing Program funds, the Recovery Program funds and actions supported by them cannot be considered in determining expeditious progress made in the Listing Program.) As with our “precluded” finding, expeditious progress in adding qualified species to the Lists is a function of the resources available and the competing demands for those funds. Given that limitation, we find that we are making progress in FY 2010 in the Listing Program. This progress included preparing and publishing the following determinations (Table 13):
Our expeditious progress also includes work on listing actions that we funded in FY 2010, and for which work is ongoing but not yet completed to date. These actions are listed below (Table 14). Actions in the top section of the table are being conducted under a deadline set by a court. Actions in the middle section of the table are being conducted to meet statutory timelines, that is, timelines required under the Act. Actions in the bottom section of the table are high-priority listing actions. These actions include work primarily on species with an LPN of 2, and selection of these species is partially based on available staff resources, and when appropriate, include species with a lower priority if they overlap geographically or have the same threats as the species with the high priority. Including these species together in the same proposed rule results in considerable savings in time and funding, as compared to preparing separate proposed rules for each of them in the future.
We have endeavored to make our listing actions as efficient and timely as possible, given the requirements of the relevant laws and regulations, and constraints relating to workload and personnel. We are continually considering ways to streamline processes or achieve economies of scale, such as by batching related actions together. Given our limited budget for implementing section 4 of the Act, the actions described above collectively constitute expeditious progress.
The greater sage-grouse and the Bi-State DPS of the greater sage-grouse will each be added to the list of candidate species upon publication of these 12–month findings. We will continue to monitor their status as new information becomes available. This review will determine if a change in status is warranted, including the need to make prompt use of emergency listing procedures. We acknowledge we must reevaluate the status of the Columbia Basin population as it relates to the greater sage-grouse; we will conduct this analysis as our priorities allow. Other populations of the greater sage-grouse, as appropriate, will be evaluated to determine if they meet the distinct population segment (DPS) policy prior to a listing action, if necessary and appropriate.
We intend that any proposed listing action for the greater sage-grouse or Bi-State DPS of the greater sage-grouse will be as accurate as possible. Therefore, we will continue to accept additional information and comments from all concerned governmental agencies, the scientific community, industry, or any other interested party concerning these findings.
A complete list of references cited is available on the Internet at
The primary authors of this notice are the staff members of the Wyoming, Montana, Idaho, Nevada, and Oregon Ecological Services Offices.
The authority for this section is section 4 of the Endangered Species Act of 1973, as amended (16 U.S.C. 1531