Fish and Wildlife Service, Interior.
Notice of 12-month petition finding.
We, the U.S. Fish and Wildlife Service, announce a 12-month finding for a petition to list Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus) throughout its known historic range in the 48 contiguous United States under the Endangered Species Act of 1973, as amended. We have reviewed the petition, information available in our files, other published and unpublished information submitted to us during the public comment period following the 90-day petition finding, consulted with recognized prairie grouse experts, and coordinated with other Federal, State, and tribal resource agencies within the historic range of the subspecies. On the basis of the best scientific and commercial information available, we find that listing the Columbian sharp-tailed grouse as a threatened species throughout its historic range in the contiguous United States is not warranted at this time.
The finding announced in this document was made September 27, 2000. Comments and information may be submitted until further notice is given by a document published in the Federal Register.
Data, information, comments, and material concerning the petition finding may be submitted to the Field Supervisor, Upper Columbia River Basin Field Office, U.S. Fish and Wildlife Service, 11103 East Montgomery Drive, Spokane, Washington, 99206. The 12-month petition finding, supporting data, and comments are available for public inspection, by appointment, during normal business hours at the above address.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Chris Warren at the above address or telephone (509) 893-8020.End Further Info End Preamble Start Supplemental Information
Section 4(b)(3)(B) of the Endangered Species Act of 1973 (Act), as amended (16 U.S.C. 1531 et seq.), requires, to the maximum extent practicable, that we make a finding within 12 months of the date of receipt of a petition containing substantial information on whether the petitioned action is: (a) not warranted, (b) warranted, or (c) warranted but precluded from an immediate proposal by other pending proposals of higher priority. Upon making a 12-month finding, we must promptly publish such notice in the Federal Register.
On March 16, 1995, we received a petition from the Biodiversity Legal Foundation, Boulder, Colorado, dated March 14, 1995. The petitioner requested that the Columbian sharp-tailed grouse be listed as a threatened species throughout its known historic range in the 48 contiguous United States and that critical habitat be designated for the species as soon as its biological needs are sufficiently well known. The petition also recommended a review of the species' status in British Columbia, Canada.
We added the Columbian sharp-tailed grouse to our candidate species list on January 6, 1989, as a Category 2 species (54 FR 560). Category 2 species were those for which we possessed information indicating that a proposal to list as endangered or threatened was possibly appropriate, but for which conclusive data on biological vulnerability and threats were not available to support a proposed rule. On February 28, 1996, we discontinued the designation of Category 2 species as candidates for listing under the Act (61 FR 7596).
Due to a backlog of listing actions and funding constraints in our listing program, we have implemented our Listing Priority Guidance during the course of listing actions for the subject petition. The guidance, first adopted on Start Printed Page 60392September 21, 1983 (48 FR 43098), was updated on May 16, 1996 (61 FR 24722), December 5, 1996 (61 FR 64475), May 8, 1998 (63 FR 25502), and, most recently, on October 22, 1999 (64 FR 57114). The guidance is a biologically based method of prioritizing listing actions to provide the greatest conservation benefit to imperiled species in the most expeditious manner. On October 26, 1999, we determined that the petition presented substantial information and that the petition action may be warranted. We published an announcement of our administrative finding (64 FR 57620). At that time, we initiated a status review of the Columbian sharp-tailed grouse in accordance with our Listing Priority Guidance.
The Columbian sharp-tailed grouse is one of seven recognized subspecies of sharp-tailed grouse that have been described in North America (AOU 1957, Aldrich 1963, Johnsgard 1973, Miller and Graul 1980, Connelly et al. 1998). Compared to the other subspecies, Columbian sharp-tailed grouse are the smallest and have darker gray plumage, more pronounced spotting on the throat, and narrower markings on the underside. Historically, Columbian sharp-tailed grouse range extended westward from the continental divide in Montana, Idaho, Wyoming, and Colorado to northeastern California and eastern Oregon and Washington; southward to northern Nevada and central Utah; and northward through central and extreme southeastern British Columbia.
Columbian sharp-tailed grouse rely on a variety of good quality native habitats within the sagebrush-bunchgrass, meadow-steppe, mountain shrub, and riparian zones of the northwestern United States (Giesen and Connelly 1993). Various upland habitats, with a component of more dense riparian or mountain shrub habitat to provide escape cover, are important to the subspecies from spring to fall (Saab and Marks 1992, Giesen and Connelly 1993). Suitable wintering habitat, that consists largely of deciduous trees and shrubs, is also thought to be a key element to healthy Columbian sharp-tailed grouse populations (Marshall and Jensen 1937, Hart et al. 1950, Marks and Marks 1987, Giesen and Connelly 1993).
Male sharp-tailed grouse employ elaborate courtship displays in the spring to attract females to central dancing grounds, called leks. Established leks may be used for many years, although the exact dancing locations may shift position over time and smaller satellite leks often form in the vicinity of historic leks. Interacting clusters of leks in a local area, where males and females may switch sites within and between seasons, are defined as lek complexes (Schroeder et al., pers. comm. 2000). Individual leks can consist of several to over 30 displaying males, under good conditions 15 to 25 males per lek are common (Meints, Idaho Dept. of Fish and Game, pers. comm. 1995 and 1998; Schroeder, Washington Dept. of Fish and Wildlife (WDFW), pers. comm. 1995, 1998, and 2000). Due to social structures within a lek and other potential influences, such as exposure to predation, leks seldom support more than 25 males (Moyles and Boag 1981, Rodgers 1992, Connelly et al. 1998). The few dominant males at a lek's center account for the majority of successful mating attempts (Leopold et al. 1981, Moyles and Boag 1981).
Spring-to-fall home range sizes of Columbian sharp-tailed grouse are relatively small, generally less than 2 square kilometers (km2) (1.2 square miles (mi2)), and the areas used are usually within a few km (mi) of a lek. Females typically nest and rear their broods within 1.6 km (1 mi) of an active lek, although nesting more than 3 km (1.9 mi) from a lek has been recorded (Saab and Marks 1992, Giesen and Connelly 1993). Seasonal movements to wintering areas from breeding grounds are typically less than 5 km (3.1 mi) (Giesen and Connelly 1993), although movements of up to 20 km (12.4 mi) have been recorded (Meints 1991). The annual survival rate of sharp-tailed grouse is relatively low, and ranges from roughly 20 to 50 percent (WDFW 1995, Connelly et al. 1998).
The area within 2.5 km (1.6 mi) of a lek is thought to be critical to the management of Columbian sharp-tailed grouse and this area should contain, or provide access to, suitable wintering habitats (Saab and Marks 1992, Giesen and Connelly 1993). Because of their influence on the species' demographics, leks (including the surrounding area) can be viewed as the principal units describing the arrangement of sharp-tailed grouse populations. Columbian sharp-tailed grouse assemblages range from local populations (single leks to lek complexes), to regional populations (potentially interacting local populations occupying small geographic areas, such as a county), to metapopulations (potentially interacting regional populations occupying larger geographic areas).
Various historic accounts indicate that Columbian sharp-tailed grouse were once much more abundant throughout their range where suitable habitats occurred (Hart et al. 1950, Buss and Dziedzic 1955, Gruell circa 1960, WDFW 1995). Excessive hunting in the mid to late 19th century is thought to have been a major contributing factor to the early extirpation of local populations and the initial reduction of the subspecies' range (Hart et al. 1950). However, since the turn of the century, the conversion of native habitats for crop production and their degradation as a result of heavy livestock grazing are thought to be the primary factors in further population declines and range reductions (Hart et al. 1950, Buss and Dziedzic 1955, Miller and Graul 1980, Marks and Marks 1987, Braun et al. 1994, WDFW 1995, McDonald and Reese 1998, Connelly et al. 1998). Columbian sharp-tailed grouse have been extirpated from California, Nevada, and Oregon (Miller and Graul 1980, Connelly et al. 1998). Past declines in the subspecies' overall abundance and extent of occupied range have isolated various populations of Columbian sharp-tailed grouse from one another since the mid-1900's (cf Hart et al. 1950).
When large geographic areas are considered (e.g., states and provinces), the overall distribution of Columbian sharp-tailed grouse appears to have changed little since the mid-1900's, and various sources have acknowledged the difficulty of obtaining accurate population estimates for the subspecies (Hart et al. 1950, Rogers 1969, Miller and Graul 1980, Schroeder et al., pers. comm. 2000). However, when smaller geographic areas are considered (e.g., local populations, regional populations), a general pattern of continued range reduction and population decline is apparent from the mid-1900's to the present (Miller and Graul 1980; WDFW 1995; Ritcey 1995; Schroeder et al., pers. comm. 2000; Mitchell, Utah Dept. of Natural Resources, pers. comm. 1995 and 1998; Hoffman, Colorado Dept. of Fish and Game, pers. comm. 1995 and 1998; Thier, Montana Dept. of Fish, Wildlife, and Parks, pers. comm. 1998; Chutter, B.C. Min. of Env., Wildlife Branch, pers. comm. 1995). Based on a questionnaire distributed to wildlife professionals in 1979 throughout the species' range, Miller and Graul (1980) state that populations of Columbian sharp-tailed grouse occupy less than 10 percent of their former range in Idaho, Montana, Utah, and Wyoming, 10 to 50 percent in Colorado and Washington, and 80 percent or more in British Columbia.
Most current population estimates have been derived from spring breeding population censuses collected by state and Federal agencies over the last two Start Printed Page 60393decades. In general, estimates of fall population sizes are roughly double that of the spring breeding population. Most of the following discussions of distribution and abundance of Columbian sharp-tailed grouse by State and province are based on published and unpublished agency reports furnished after submission of the petition in March 1995, and during the public comment period for the status review, initiated in October 26, 1999. These reports are cited below, as appropriate. In addition, the following information is based on the best estimates of recognized experts (SRTIM 2000), and an independent report solicited by the Service that addresses the viability of the various extant Columbian sharp-tailed grouse populations (Bart 2000). This report was prepared using and summarizing data submitted by State and Bureau of Land Management offices and on maps of historic and current distributions of Columbian sharp-tailed grouse prepared by Schroeder (2000) using information obtained from State and Federal biologists working on this species.
Based on the best available information, the current minimum to maximum breeding population estimate for Columbian sharp-tailed grouse is approximately 51,000 to 52,000 (mean = 51,500) individuals within the U.S., and 56,000 to 61,500 (mean = 58,700) individuals within the total range. These populations occupy approximately 38,400 km2 (23,800 mi2) within the U.S. and 79,300 km2 (49,200 mi2) rangewide. Over 93 percent of all Columbian sharp-tailed grouse occur within the three metapopulations in northwest Colorado/south-central Wyoming (roughly 4,800 birds), southeastern Idaho/northern Utah (roughly 40,000 birds in Idaho and 5,100 in Utah), and central British Columbia (4,700 to 9,600). These three metapopulations are reported to be either stable or increasing (state reports summarized in Bart 2000). Rangewide, these three metapopulations including the stable population within British Columbia, stable and/or increasing populations occupy approximately 68,000 km2 (42,200 mi2) which is over 85 percent of the occupied range (79,300 km2) (49,200 mi2).
Colorado (Mumma, in litt. 1999; Bart 2000; House, in litt. 2000)—There are two subpopulations of Columbian sharp-tailed grouse in Colorado. The northwest region contains numerous interacting local populations with multiple leks, which likely constitute a distinct, interacting metapopulation totaling roughly 4,700 birds in the spring breeding population (9 percent of the current rangewide spring breeding population within the United States (U.S.)) and occupies about 8,700 km2 (5,400 mi2) (23 percent of the current range within the U.S.). This population occurs primarily in Moffat, Routt, and Rio Blanco Counties, and is continuous with local populations in south-central Wyoming (see below). Current trend data indicate the population is likely stable and increasing. Mesa County, in the west-central region, may still harbor a remnant local population. If this population still exists, it is isolated from other regional populations. The last confirmed sightings of birds in this area are from circa 1985. The spring breeding population is estimated to currently be comprised of up to 50 birds (less than 1 percent of the rangewide population within the U.S.) and inhabit about 1,600 km2 (990 mi2) (approximately 4 percent of the currently occupied U.S. range).
Idaho (Meints, pers. comm., 1995, 1998; Bart 2000; Mallet, in litt. 2000)—There are three subpopulations of Columbian sharp-tailed grouse occupying the state of Idaho. The southeastern region contains numerous, interacting local populations with multiple leks, which likely constitute a distinct, interacting metapopulation totaling roughly 40,000 birds in the spring breeding population (78 percent of the rangewide population within the U.S.). The population occupies approximately 14,800 km2 (9,200 mi2) (39 percent of the current range within the U.S.). This population is likely stable and increasing. It occurs primarily south of Rexburg and east of Rupert, Idaho, and is continuous with local populations in northern Utah (see below). The upper Snake River region, including the Sand Creek and Tex Creek areas, harbors roughly 600 birds in the spring breeding population (approximately 300 in each area). Birds from these two areas likely interact with one another and with the larger population in the southeastern region. This population is reported to be stable. Washington and Adams Counties, in the west-central region, harbor roughly 200 to 300 birds in the spring breeding population (less than 1 percent of the total U.S. population), which supports approximately 7 leks over about 1,690 km2 (1,050 mi2) (4 percent of the current range within the U.S.). The population is reported to be stable, although the area is isolated from other regional populations. Translocation efforts conducted in extreme south-central Idaho beginning in 1992 have resulted in an isolated local population (200 to 400 birds in the spring breeding population; less than 1 percent of U.S. total), supporting at least 3 leks over 175 km2 (110mi2) (less than 1 percent of the total range within the U.S.). This area is contiguous with a small population of reintroduced birds in northeastern Nevada (see below). Translocated birds originated from the population in southeastern Idaho.
Montana (Wood 1991; Wood 1992; Bart 2000; McCarthy, in litt. 2000)—Two small local populations occur in the northwestern region of this state, one in Lincoln County near the international boundary with British Columbia, the other to the southeast in Powell County. The Lincoln County area supports fewer than 30 birds in the spring breeding population on a single lek, while the Powell County area supports fewer than 50 birds in the spring breeding population on a few leks. From 1987 through 1991, and again in 1996 and 1997, the Lincoln County population was augmented with birds translocated primarily from central British Columbia (one effort included birds translocated from southeastern Idaho). The taxonomic status of the Powell County population is in question. Based on evaluation of a limited number of specimens, these birds may show a greater morphological affinity to the plains subspecies. These two local populations are isolated from one another and from other regional populations. During the early 1970s and again in 1980, limited efforts to reintroduce sharp-tailed grouse to the National Bison Range (roughly 50 km (30 mi) northwest of Missoula) were conducted with birds translocated from southeastern Idaho. It is unlikely that any of these birds or their offspring persisted in the area. Both of these populations are probably still declining, but comprise less than 1 percent of the total U.S. subpopulation.
Nevada (Morros 1999; Crawforth, in litt. 2000)—One introduced population currently exists in Nevada. During the spring of 1999, 54 birds were translocated to the Snake Range in Elko County. Translocated birds originated from the population in southeastern Idaho. The most recent census information indicates there are roughly 20 to 40 birds remaining from this initial effort. Additional translocation efforts are planned through 2003, with a goal of releasing approximately 50 birds per year from the same source population. This reintroduced local population is likely continuous with reintroduced birds in south-central Idaho (see above).
Oregon (Crawford and Snyder 1992, Bart 2000, Crawford and Coggins 2000)—One introduced population currently exists in Oregon. From 1991 Start Printed Page 60394through 1997, a total of 179 birds had been translocated into Wallowa County in northeastern Oregon from the population in southeastern Idaho. As the result of these reintroduction efforts, an isolated local population may have been established. Recent census information indicates there are roughly 15 to 30 individuals in the spring breeding population, supporting one or few leks, and the population is likely declining.
Utah (Bart 2000; Mitchell, in litt. 2000)—One subpopulation currently exists in northern Utah. It contains numerous, interacting local populations with multiple leks, which likely constitute a distinct, interacting metapopulation totaling roughly 5,100 birds in the spring breeding population (10 percent of the U.S. subpopulation). This population is continuous with the population in southeastern Idaho (see above) and is reported to be stable and increasing, currently occupying roughly 3,600 km2 (2,200 mi2) (9 percent of the range within the U.S.) .
Washington (Schroeder, in litt. 2000; Cawston, in litt. 2000; Schroeder et al., pers. comm. 2000)—Eight local populations occur in north-central Washington; 3 likely have multiple leks, while 5 consist of single or few leks. The overall estimate for the State is approximately 900 individuals in the spring breeding population. Some minimal interaction may occur between a few local populations, while others are isolated. The region is isolated from other regional populations and comprises approximately 1,700 km2 (1,100 mi2) (4 percent of the range within the U.S.). During the spring of 1998, and again in 1999, translocation efforts were conducted to augment one of the remnant, local populations in north-central Washington. Translocated birds originated from the population in southeastern Idaho. The Nespelem population is reported to be stable, but the remainder of the populations are likely declining.
Wyoming (Oedekoven 1985; Kruse, in litt. 1999; Bart 2000)—The most recent census information for Wyoming indicates there is one population in the south-central region of the state, consisting of roughly 100 to 500 birds in the spring breeding population (less than 1 percent of the U.S. subpopulation) and supporting multiple leks over 2,500 km2 (1,600 mi2) (6 percent of the range within the U.S.). The population occurs in Carbon County and is continuous with the population in northwestern Colorado (see above). This population is reported to be stable.
British Columbia, Canada (Ritcey 1995; Chutter, pers. comm. 1995; Bart 2000)—The central region of British Columbia (Fraser Plateau) contains numerous, interacting local populations with multiple leks, which likely constitute a distinct, interacting metapopulation totaling roughly 4,700 to 9,600 birds in the spring breeding population (averaging 12 percent of the rangewide subpopulation) over an area of approximately 41,000 km2 (25,000 mi2) (51 percent of the current rangewide area). This metapopulation is reported to be stable. The available information indicates that the more northerly populations of Columbian sharp-tailed grouse in British Columbia may show a greater morphological and behavioral affinity to the northern subspecies (Tympanuchus phasianellus caurus). The area directly south of Cranbrook (southeastern region) may contain one local population with single to few leks. This population is isolated from other regional populations. The area south of Merritt to the Washington border (south-central region) contains individual birds or small flocks during the winter, with no breeding behavior (i.e., leks) apparent.
Section 4(a) of the Act describes five threat factors that we must consider to determine whether any species is a threatened or endangered species for purposes of the Act. Any one or combination of the five threat factors may indicate the appropriateness of a warranted 12-month administrative finding. Section 4(b) of the Act requires that we also give consideration in our determination of a species' status to efforts being made by any state or foreign nation to protect such species. Below, the available information is considered with regard to the five threat factors established by the Act and any ongoing conservation measures for Columbian sharp-tailed grouse.
(1) Present or Threatened Destruction, Modification, or Curtailment of Habitat or Range
Large portions of native habitats historically used by Columbian sharp-tailed grouse have been converted for crop production and impacted by other influences, including rural and suburban development, dam construction, minerals exploitation, chaining, herbicide spraying, and fire (Miller and Graul 1980; Wood 1991; Giesen and Connelly 1993; Schroeder, pers. comm. 1995 and 1998; Mitchell, pers. comm. 1995 and 1998; Chutter, pers. comm. 1995). In addition, past grazing practices over large portions of historic Columbian sharp-tailed grouse range have impacted native habitats (Hart et al. 1950, Miller and Graul 1980, Kessler and Bosch 1982, Wood 1992, Giesen and Connelly 1993). Intensive grazing pressure can be especially detrimental to nesting and wintering habitats potentially used by sharp-tailed grouse, primarily due to impacts on cover and food resources. However, much of the area currently occupied by Columbian sharp-tailed grouse is not subject to intensive grazing pressure (SRTIM 2000, see below).
Most of the area currently occupied by Columbian sharp-tailed grouse is privately owned (Bart 2000), and a large proportion of these lands are withdrawn from crop production and planted to native and non-native cover under the Federal Conservation Reserve Program (CRP) (USDA 1998). Except under extraordinary circumstances, CRP lands are not subject to grazing and likely have increased forb and insect abundance from spring to fall, which increases the value of these lands to Columbian sharp-tailed grouse females who make substantial use of CRP areas during nesting and brood-rearing (C. Warren, FWS, Spokane, in litt. 2000). CRP lands, and probably substantial amounts of adjacent “native” habitat (including important wintering habitat in some regions), are essentially free of pesticide and herbicide applications and grazing pressure (Warren, in litt. 2000). Accordingly, these CRP areas have become very important Columbian sharp-tailed grouse large metapopulations in Colorado, Idaho, Utah, and Wyoming (SRTIM 2000, Bart 2000).
A majority of CRP that are 10-year contracts for lands in States supporting Columbian sharp-tailed grouse were renewed after 1997, resulting in 92 to 99 percent of these lands being relatively secure until the years 2008 through 2010 (Warren, in litt. 2000). Between the fall of 1997 and the fall of 1998, the total amount of CRP land available to Columbian sharp-tailed grouse increased within all of the counties harboring the subspecies' metapopulations within the United States, including 25, 7, and 1 percent increases in Utah, Colorado, and Idaho, respectively. Lands under CRP contract as of the year 2000 show 1 to 7 percent acreage increases over those in 1998 (Warren, in litt. 2000).
The potential net changes that may occur under the CRP or if CRP contracts expire, vary considerably by county within the five States where CRP is shown to be important to Columbian sharp-tailed grouse. Presently, it is unclear what effects these changes may have on the subspecies' populations. If CRP lands that are important to the Start Printed Page 60395smaller populations of Columbian sharp-tailed grouse revert back to crop production or are significantly altered, adverse impacts to these populations will occur and that will increase the risk of extirpation of these smaller populations (Bart 2000). However, the larger metapopulations are likely capable of adjusting to these potential impacts and would not be adversely effected. This is because smaller subpopulations within the region could supply a source for recolonization of modified sites, or alternate areas of suitable habitat would be developed under new CRP contracts to allow the affected local populations to adjust to the changes.
Reclaimed mining lands have also become important to the conservation of Columbian sharp-tailed grouse in northwestern Colorado (Mumma, in litt. 1999). These areas fall under the requirements of the Colorado Mined Land Reclamation Act (CMLRA). There is currently little information available regarding the ultimate fate of these areas upon termination of the reclamation bonds. However, it is not assured that they will be converted by development or subject to intensive grazing pressure following bond release. In addition, as with CRP contracts, it is likely that newly reclaimed areas will become available to Columbian sharp-tailed grouse in Colorado as current and future mining operations are completed.
(2) Overutilization for Commercial, Recreational, Scientific, or Educational Purposes
Currently, Columbian sharp-tailed grouse are hunted in the fall in Colorado, Idaho, Utah, and British Columbia. Fall population sizes are roughly double that of the estimated spring breeding populations. Colorado maintains a fall hunting season in 1998 and 1999 in the northwest region, with bag and possession limits of two and four birds, respectively. Over the last four years, the annual state harvest estimate has averaged 218 birds, which is 2 percent of a fall population of approximately 9,500 birds. Idaho also maintains a fall hunting season in 1998 and 1999, with bag and possession limits of two and four birds, respectively. The latest available information indicates that a total of roughly 3,000 birds are harvested annually from the southeastern and upper Snake River regions, which is approximately 4 percent of the fall population of about 80,000 birds. Utah reopened its hunting season in 1998 and 1999. Over the past 2 years, Utah has issued 663 2-bird permits in a limited-entry hunt. The State harvest estimates for 1998 and 1999 were 201 birds (less than 2 percent) and 462 birds (less than 5 percent), respectively, of an approximate fall population of 10,200 birds. In British Columbia, it is estimated that up to 5,000 birds (35 percent of an average fall population of 14,300 birds) are harvested during some hunting seasons, however, this estimate is not based on rigorous surveys and is subject to wide year-to-year variation.
For relatively large, stable populations of upland birds under managed conditions, hunting is not likely to have an additive effect over natural mortality because the percentage of the population that is eliminated through hunting mortality is minimal and compensated through the normal population processes of reproduction and immigration (Braun et al. 1994, SRTIM 2000). Depending on the status of the hunted population and hunter access patterns, some local areas may act as population sinks and be adversely impacted by the additional mortality. However, the estimated harvest rates are not likely to adversely effect the metapopulations of Columbian sharp-tailed grouse in the States with hunting seasons (Bart 2000).
Several reintroduction efforts have taken place or are planned for Columbian sharp-tailed grouse. The relatively small, isolated populations would be adversely impacted by the removal of source birds for these projects, as may have occurred in British Columbia (Chutter, pers. comm. 1995). In addition, birds translocated from disparate parts of their range may not thrive or survive in the release area (Wood 1991; Thier, pers. comm. 1998). It is also unclear what effects the translocation of birds to disparate parts of their range may have on the genetic integrity of the augmented populations. Saab and Marks (1992) indicate that the conservation of all potential sources of genetic variation should be a critical concern given the fragmented, isolated nature of some of the subspecies' populations. Radio-marked birds may also be more susceptible to predation and other mortality factors (Marks and Marks 1987). The small and fragmented populations of Columbian sharp-tailed grouse would be at increased risk of extirpation from these potential threats. However, as with the potential impacts to the habitats used by the subspecies (above), the large metapopulations are not likely to be adversely affected by these management activities (Bart 2000).
(3) Disease or Predation
There are apparently no documented severe episodes of disease or predation that have played a significant role in the population declines and range reduction of Columbian sharp-tailed grouse. Episodes of disease or altered predation patterns may play an important role in the dynamics of the smaller, isolated populations and, as above, they are at increased risk of extirpation from these potential threats. However, these threats are currently of minor concern for the subspecies' metapopulations.
(4) Inadequacy of Existing Regulatory Mechanisms
In the majority of the subspecies' current range regulatory mechanisms and conservation measures are apparently adequate for maintaining viable populations of Columbian sharp-tailed grouse.
State hunting regulations appear to be sufficient to control the legal take of Columbian sharp-tailed grouse where they are hunted, and to avoid adverse impacts to these populations (above). In addition, the revegetation and reclamation standards under the CRP and CMLRA, respectively, promote the improvement of habitat conditions for the subspecies' metapopulations, and the CRP restricts livestock grazing on contract lands except under extraordinary circumstances.
(5) Other Natural or Human-Caused Factors Affecting the Species' Continued Existence
The fragmented, isolated nature of some local populations of Columbian sharp-tailed grouse may place them at increased risk of extirpation (Bart 2000). Random environmental and human-influenced events could cause significant mortality to, or disruption of, local populations of Columbian sharp-tailed grouse with single or few leks. Such events could include drought, fire, inclement weather, accidents, cultivation practices, recreational activities, altered predator dynamics, or disease epidemics (Hart et al. 1950; Rogers 1969; WDFW 1995; Mitchell, pers. comm. 1995 and 1998). If the affected population is also isolated, there is little chance of reestablishment to the area and further range reduction is likely to occur.
There is also concern regarding the lack of sufficient data with respect to the genetic integrity of the subspecies' various populations (Saab and Marks 1992). The deleterious effects of inbreeding and genetic drift may pose long-term threats to the smaller, isolated populations. The breeding dynamics of Columbian sharp-tailed grouse and their relatively short life spans and sedentary habits may exacerbate these potential influences. Conservation or reestablishment of such populations Start Printed Page 60396may require intensive management efforts (Toepfer et al. 1990).
The factors discussed above are not considered to be threats to the subspecies because the large, stable metapopulations that occur in Colorado, Idaho, and Utah, representing roughly 97 percent of the subspecies within the U.S., would likely not be affected.
In summary, the available information indicates that the subspecies' metapopulations are relatively secure. These large metapopulations have persisted for the last several decades with no discernable downward trend, and recent information indicates that they may currently be increasing, as are the habitats available to them (SRTIM 2000). However, most of the small, isolated populations of Columbian sharp-tailed grouse will likely be extirpated within a few decades due to existing threats and current management scenarios (Bart 2000).
An inter-agency (Federal and State) team is currently preparing a conservation assessment for Columbian sharp-tailed grouse in Idaho (Ulliman et al. 1998). Upon its completion, the conservation strategy developed in Idaho may be used as a general model for conservation actions in other States and British Columbia.
The Colorado Division of Wildlife helped form and participates on the Northwest Colorado Columbian Sharp-tailed Grouse Work Group (Mumma, in litt. 1999). The work group includes interested parties representing resource industries, sportsmen's and conservation groups, and State and Federal resource agencies. The work group is currently developing a formal conservation plan, and is committed to improving conditions for the Columbian sharp-tailed grouse population in the northwest region of the State.
The Washington Department of Fish and Wildlife has prepared a management plan for Columbian sharp-tailed grouse occurring within the State (WDFW 1995), and has recently listed Columbian sharp-tailed grouse as a State threatened species (WDFW 1998a). Washington currently has a program to acquire lands for the protection and active management of Columbian sharp-tailed grouse (WDFW 1998b). Restoration and enhancement of native habitats to improve conditions for existing (and potential) populations are planned for these areas (Schroeder, pers. comm. 1995 and 1998).
Reintroduction efforts for Columbian sharp-tailed grouse have taken place in Washington, Montana, Oregon, Idaho, and Nevada (SRTIM 2000). Many early reintroduction efforts conducted for prairie grouse (including sharp-tailed grouse) failed to produce self-sustaining populations or to increase the size or distribution of augmented populations (Toepfer et al. 1990). Several recent efforts have shown greater potential to be effective as the techniques for reintroductions have improved (Toepfer et al. 1990; Crawforth, in litt. 2000; Schroeder, pers. comm. 1995 and 1998; Meints, pers. comm. 1995 and 1998). However, most of these improvements have been concerned with keeping translocated birds in the immediate vicinity of the release sites during the breeding season. While some reintroduced birds have established leks and reproduced in the release area over a number of years, none of these populations can yet be considered secure (Bart 2000). Continuing reintroduction efforts are planned for Idaho, Nevada, Washington, and Oregon; and various reintroduction efforts are being considered for California, Colorado, and Montana (SRTIM 2000).
Columbian sharp-tailed grouse populations in British Columbia may be expanding on the periphery of their current range where logging activity has created suitable open, grassland habitat. While this is not an active enhancement effort, the beneficial effects of these activities are believed to last up to approximately 15 years (Ritcey 1995; Chutter, pers. comm. 1995).
We have reviewed the petition, literature cited in the petition, other pertinent literature and information available in our files, and consulted with biologists and researchers familiar with Columbian sharp-tailed grouse. After reviewing the best scientific and commercial information available, and considering the information's significance with regard to the five listing factors established by the Act and ongoing conservation measures, we find that listing the Columbian sharp-tailed grouse as a threatened species throughout its known historic range in the 48 contiguous United States, as petitioned is not warranted.
In making this finding, we recognize that there have been declines in Columbian sharp-tailed grouse populations primarily attributed to the loss and degradation of important shrub steppe, grassland, and riparian habitats. These impacts are likely due to a combination of factors including crop production, over-grazing by livestock, altered fire frequencies, rural and suburban development, dam construction, herbicide spraying, recreation, and other factors. The Service's status review of the Columbian sharp-tailed grouse range wide has raised concern regarding the status of many of the small populations such that a further status review focusing on these populations will be initiated. However, the available information does not indicate that the large metapopulations of the subspecies are at increased risk of extirpation. We also recognize that various State and Federal agencies throughout the subspecies' historic distribution are actively managing the populations to try and improve their overall status and/or attempting to restore them to currently unoccupied habitats. If information becomes available indicating that listing as endangered or threatened is appropriate, we would propose to list the Columbia sharp-tailed grouse. Furthermore, we retain the option of recognizing a population segment for listing should information become available indicating that such an action is appropriate and warranted.
A complete list of all references cited herein is available on request from the Upper Columbia River Basin Field Office, (See ADDRESSES section).
The primary author of this notice is Chris Warren, U.S. Fish and Wildlife Service, 11103 East Montgomery Drive, Spokane, Washington 99206.Start Signature
Dated: September 27, 2000.
Jamie Rappaport Clark,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 00-25447 Filed 10-10-00; 8:45 am]
BILLING CODE 4310-55-P