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Proposed Rule

Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Smooth-Billed Ani as Threatened or Endangered

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AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Notice of 90-day petition finding.

SUMMARY:

We, the U.S. Fish and Wildlife Service, announce a 90-day finding on a petition to list the smooth-billed ani (Crotophaga ani) as threatened or endangered under the Endangered Species Act of 1973, as amended (Act). Based on our review, we find that the petition does not present substantial information indicating that listing the species may be warranted. Therefore, we are not initiating a status review in response to this petition. However, we ask the public to submit to us any new information that becomes available concerning the status of, or threats to, the smooth-billed ani or its habitat at any time.

DATES:

The finding announced in this document was made on April 26, 2011.

ADDRESSES:

This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R4-ES-2011-0007. Supporting documentation we used in preparing this finding is available for public inspection, by appointment, during normal business hours at the U.S. Fish and Wildlife Service, South Florida Ecological Services Office, 1339 20th Street, Vero Beach, Florida 32960-3559. Please submit any new information, materials, comments, or questions concerning this finding to the above address.

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FOR FURTHER INFORMATION CONTACT:

Spencer Simon, Assistant Field Supervisor, of the South Florida Ecological Services Office (see ADDRESSES) by telephone 772-562-3909, or by facsimile to 772-562-4288. If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800-877-8339.

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SUPPLEMENTARY INFORMATION:

Background

Section 4(b)(3)(A) of the Act (16 U.S.C. 1531 et seq.) requires that we make a finding on whether a petition to Start Printed Page 23266list, delist, or reclassify a species presents substantial scientific or commercial information indicating that the petitioned action may be warranted. We are to base this finding on information provided in the petition, supporting information submitted with the petition, and information otherwise available in our files. To the maximum extent practicable, we are to make this finding within 90 days of our receipt of the petition and publish our notice of the finding promptly in the Federal Register.

Our standard for substantial scientific or commercial information within the Code of Federal Regulations (CFR) with regard to a 90-day petition finding is “that amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted” (50 CFR 424.14(b)). If we find that substantial scientific or commercial information was presented, we are required to promptly conduct a species status review, which we subsequently summarize in our 12-month finding.

Petition History

On April 5, 2005, we received a petition, dated March 23, 2005, from Robert Showler of Homestead, Florida, requesting that the smooth-billed ani (Crotophaga ani), a bird, be listed as endangered under the Act. The petition clearly identified itself as such and included the requisite identification information for the petitioner(s), as required by 50 CFR 424.14(a). In an April 29, 2005, letter to the petitioner, we responded that we received the petition for the smooth-billed ani, and that because of inadequate funding for listing-related actions pursuant to court orders and judicially approved settlement agreements, we would not be able to address the petition at that time. We also noted that the species had been included on the list of birds of conservation concern in peninsular Florida in 2002 and that we had begun to compile information on this and other species of conservation concern in peninsular Florida. This finding addresses the petition.

Species Information

The smooth-billed ani (Crotophaga ani) is a member of the Family Cuculidae (cuckoo family). We concur with the petition's taxonomic characterization of the smooth-billed ani (Crotophaga ani) as a species. This species is a resident in parts of Florida, the Caribbean, Mexico, and Central and South America (Stevenson and Anderson 1994, p. 355; Quinn and Startek-Foote 2000, section 3, p. 1). The smooth-billed ani is a medium-sized cuculid, with a length of 12-14 inches (30-36 centimeters) and a mass of approximately 3.5 ounces (100 grams) (Ridgway 1916 and Loflin 1983 as cited in Quinn and Startek-Foote 2000, section 2, p. 1). Males tend to be slightly larger than females (Quinn and Startek-Foote 2000, section 2, p. 1). This species is distinguished by: all-black plumage, glossed with greenish or violet iridescence in parts; a long tail (approximately 6.8 in (17.2 cm)); a large, arched, and laterally compressed bill, usually showing a raised hump on the basal half of the upper mandible; and a distinctive call, including a whining “ah-nee,” which is usually delivered 1-4 times, along with other vocalizations (Quinn and Startek-Foote 2000, section 1, p. 1; section 2, p. 1; section 8, p. 1). Immature birds resemble adults, but their plumage contains a mixture of dull and glossy blackish feathers, and the bill is slightly shallower (Quinn and Startek-Foote 2000, section 2, p. 1). Juveniles are also similar in appearance to adults, but with plumage that is entirely dull blackish in color with little or no gloss, and a smaller bill without a raised hump (Quinn and Startek-Foote 2000, section 2, p. 1).

The smooth-billed ani occurs over a considerable global geographic range. It is considered a resident from central Florida south through the Caribbean, and south into Central and South America through Ecuador and northern Argentina, except in the Andes (Stevenson and Anderson 1994, p. 355; Quinn and Startek-Foote 2000, section 3, p. 1). The species is generally nonmigratory; however, some local movement occurs during the dry season, when many groups leave their territories and gather in large flocks with neighboring groups (Loflin 1983 as cited in Quinn and Startek-Foote 2000, section 5, p. 1). Records in the Dry Tortugas suggest some movement between the Caribbean and Florida (Robertson and Woolfenden 1992 as cited in Mlodinow and Karlson 1999, p. 241). This species may regularly disperse from the Bahamas and Cuba to Florida (Mlodinow and Karlson 1999, p. 242). The smooth-billed ani has been described as a casual occurrence north to North Carolina and west to Louisiana (Stevenson and Anderson 1994, p. 355). Vagrant records elsewhere in the United States are scarce; few acceptable records outside of Florida exist (e.g., New Jersey or Pennsylvania, North Carolina, South Carolina, and Georgia) (Mlodinow and Karlson 1999, pp. 241-242).

Throughout its range, and year round, the smooth-billed ani occupies savanna, disturbed and human-altered rural and suburban areas, open areas with brush or scrub, plantations, gardens, farmlands, and forest clearings (Quinn and Startek-Foote 2000, section 6, p. 1). Preferred habitat is considered to be open grassland (Blanchard 2000, p. 5). In Puerto Rico, Guyana, Cuba, Jamaica, Colombia, and the Galápagos Islands, this species uses cow pastures and adjacent lands (Quinn and Startek-Foote 2000, section 6, p. 1). In south Florida, density was positively correlated with amount of grazing lands and human habitation (Loflin 1983 as cited in Quinn and Startek-Foote 2000, section 6, p. 1). In general, this species typically occupies lowlands, often near the coast, preferring a source of water (e.g., marsh, pond, river) and avoiding dense forest (Quinn and Startek-Foote 2000, section 6, p. 1). In a study area in south Florida, the smooth-billed ani was found to occupy discontinuous patches of habitat (e.g., parks, nurseries, small undeveloped plots of land) and avoid tall grasses of the Everglades (Loflin 1983 as cited in Quinn and Startek-Foote 2000, section 6, p. 1). Additionally, the species has been found within and near impoundments within the Loxahatchee National Wildlife Refuge (NWR) (Service 1997, p. 48; 1998, p. 50; 1999a, p. 65; 2003a, pp. 113-114) and on various outer islands within the Florida Keys NWR Complex (Service 1992, p. 85; 1999b, p. 60; 2001, p. 69; 2003b, p. 84).

This species feeds primarily on insects and small vertebrates, especially when these forage items are abundant during the rainy season; fruit is an important component of the diet during the dry season (Quinn and Startek-Foote 2000, section 1, p. 1 and section 7, pp. 1-2; Blanchard 2000, p. 5). Fields of grass are typically used for foraging; more densely vegetated stream edges may be used for nesting and roosting (Quinn and Startek-Foote 2000, section 6, p. 1; Blanchard 2000, p. 5). The smooth-billed ani is a highly social bird that nests, roosts, feeds, and travels in pairs or in communal groups (Quinn and Startek-Foote 2000, section 9, p. 3; Blanchard 2000, pp. 5-6). This species uses a communal breeding system in which a number of females lay eggs and incubate in the same nest; late-laying females bury the eggs of early-laying females with twigs and leaves, which can create a number of layers, but only the top layer of eggs eventually hatches (Quinn and Startek-Foote 2000, section 1, p. 1; Blanchard 2000, pp. 1-101). Blanchard (2000, p. 30) found evidence for monogamy, polygamy (extra-pair fertilizations), and brood parasitism (egg-laying in the nests of other birds) in Start Printed Page 23267both single-pair and group nests in a study of the species' communal breeding system in Puerto Rico. Observed nesting groups of smooth-billed anis ranged from a single pair to 12 adults and nests containing more than 30 eggs (Blanchard 2000, p. 11). Female-female competition at the nest may result in the destruction of other females' eggs through egg burial under nesting material (Blanchard 2000, p. 11).

The smooth-billed ani has a large global population, estimated in 2004 to be 20,000,000 individuals, with less than or equal to 1 percent occurring in the United States (Rich et al. 2004, p. 70). Global long-term trend data did not exist at that time (Rich et al. 2004, p. 70). In general, little information on global population size or trends was available in Service files at the time the petition was received. Available information suggested that the smooth-billed ani's conservation status was “not threatened” (Quinn and Startek-Foote 2000, section 12, p. 1). The species was not recognized as a National Audubon Society Watch List Species or Stewardship Species (Rich et al. 2004, p. 70). The Audubon Watch List categorizes species on the list if they are declining rapidly and/or have very small populations or limited ranges and face major conservation threats (e.g., typically species of global conservation concern) or if the species are either declining or rare (e.g., typically species of national conservation concern).

The smooth-billed ani is an uncommon-to-rare resident of southern Florida (Mlodinow and Karlson 1999, p. 241). Prior to the 1930s, few records existed in Florida, suggesting that the species was rare or poorly known (Quinn and Startek-Foote 2000, section 3, p. 2). Sprunt (1939, pp. 335-336) documented the first record of breeding in Florida in 1938. By the late 1930s, the species was considered established in the Lake Okeechobee area, and subsequently breeding was recorded elsewhere in south Florida (Quinn and Startek-Foote 2000, section 3, p. 2). The species' status in Florida remained relatively unchanged until the 1960s, when increasing numbers were recorded in central and north Florida (Quinn and Startek-Foote 2000, section 3, p. 2). Based upon National Audubon Society Christmas Bird Counts, the number observed per party hour (p-hr) (average number of counts per party per hour spent censusing) tripled by 1962-63, reaching 0.17 per p-hr in West Palm Beach and 2.41 per p-hr in Fort Lauderdale (Mlodinow and Karlson 1999, p. 241). In the 1960s the species was fairly common to common from the Everglades north to Brevard County on the east coast and Lee County on the west coast (Mlodinow and Karlson 1999, p. 241). By 1968-69, the number observed reached 1.51 per p-hr in West Palm Beach and 4.20 per p-hr in Fort Lauderdale (Mlodinow and Karlson 1999, p. 241).

Numbers appeared to have peaked in Florida during the period 1968-1976, when the species was recorded north to Jacksonville Beach (Duval County) in the east and St. Petersburg (Hillsborough County) in the west (Mlodinow and Karlson 1999, p. 241; Quinn and Startek-Foote 2000, section 3, p. 2). At that time, numbers observed were typically in the 3.0-4.0 per p-hr range in Fort Lauderdale, while Fort Pierce reached 1.87 per p-hr and Sanibel Island/Captiva Island reached 0.41 per p-hr (Mlodinow and Karlson 1999, p. 241). By winter 1977-1978, numbers had declined sharply, returning to mid-1960s levels (Mlodinow and Karlson 1999, p. 241). This decline continued, and by 1988-1989, total numbers were comparable to those reported in the 1950s (Mlodinow and Karlson 1999, p. 241). The decline continued in Florida into the 1990s, and by 1998, the smooth-billed ani was found locally from the Florida Keys north to West Palm Beach on the east coast, and north to Collier County on the west coast (Mlodinow and Karlson 1999, pp. 241-242). Mlodinow and Karlson (1999, p. 242) suggested that the status of the smooth-billed ani in Florida in 1998 may be the norm rather than an aberration.

Available information in Service files suggests that the species uses Loxahatchee NWR (Service, annual narrative reports from 1996 to 2005) and the Florida Keys NWR Complex (Service, annual narrative reports from 1939 to 2003). According to a notation in the 2000 annual narrative report from Loxahatchee NWR, local long-time birders have indicated that the numbers of smooth-billed anis in south Florida and on the Refuge have declined significantly and that annual Christmas Bird Counts are showing the same trend (Service 2000, p. 110).

The reasons for expansion and contraction of the species' range in Florida are not known. Expansion may have been facilitated by residential development, which resulted in anthropogenic habitat changes that initially favored this species (Mlodinow and Karlson 1999, p. 242). However, continued residential and agricultural development, which reduced suitable habitat, and exceptionally cold winters during the 1970s may have contributed to subsequent declines (Stevenson and Anderson 1994, p. 357; Mlodinow and Karlson 1999, p. 242). Overall, the reasons for the decline in south Florida are not clear (Mlodinow and Karlson 1999, p. 242; National Audubon Society 2001, p. 335).

The smooth-billed ani was one of 668 taxa evaluated in an effort to help prioritize vertebrate conservation efforts in Florida (Millsap et al. 1990, pp. 3-57). The evaluation system ranked taxa (species and subspecies) according to biological vulnerability, extent of current knowledge of population status, and management needs (Millsap et al. 1990, pp. 3-57). During this ranking process, the smooth-billed ani was not considered to be an imperiled taxon in Florida as indicated from its biological score, which was based upon facets of its distribution, abundance, and life history (Millsap et al. 1990, pp. 28-29).

Information available in Service files at the time the petition was received indicated that, in 2002, the Service's Division of Migratory Bird Management included the smooth-billed ani as a bird of conservation concern in peninsular Florida in its report, entitled “Birds of Conservation Concern 2002” (Service 2002, p. 68). The purpose of the report was to identify migratory and nonmigratory birds of the United States and its territories that are of conservation concern to encourage coordinated and proactive conservation actions among Federal, State, and private partners (Service 2002, p. 3). The overall goal of that report was to accurately identify the migratory and nonmigratory bird species (beyond those already designated as federally threatened or endangered) that represented the Service's highest conservation priorities and draw attention to species in need of conservation action (Service 2002, p. 3). The geographic scope of this endeavor comprised the United States in its entirety, including island “territories” in the Pacific and Caribbean (Service 2002, p. 1). Although the smooth-billed ani was identified as one of 78 birds of conservation concern in the Southeast, only the U.S. mainland portion of the Region was identified as of concern; Puerto Rico and the U.S. Virgin Islands were not identified as of concern (Service 2002, p. 68). In addition, the report does not include foreign countries.

Evaluation of Information for This Finding

Section 4 of the Act (16 U.S.C. 1533) and its implementing regulations at 50 CFR part 424 set forth the procedures for adding a species to, or removing a species from, the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be Start Printed Page 23268determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act:

(A) The present or threatened destruction, modification, or curtailment of its habitat or range;

(B) Overutilization for commercial, recreational, scientific, or educational purposes;

(C) Disease or predation;

(D) The inadequacy of existing regulatory mechanisms; or

(E) Other natural or manmade factors affecting its continued existence.

In considering what factors might constitute threats, we must look beyond the mere exposure of the species to the factor to determine whether the species responds to the factor in a way that causes actual impacts to the species. If there is exposure to a factor, but no response, or only a positive response, that factor is not a threat. If there is exposure and the species responds negatively, the factor may be a threat and we then attempt to determine how significant a threat it is. If the threat is significant, it may drive or contribute to the risk of extinction of the species such that the species may warrant listing as threatened or endangered as those terms are defined by the Act. This does not necessarily require empirical proof of a threat. The combination of exposure and some corroborating evidence of how the species is likely impacted could suffice. The mere identification of factors that could impact a species negatively may not be sufficient to compel a finding that listing may be warranted. The information shall contain evidence sufficient to suggest that these factors may be operative threats that act on the species to the point that the species may meet the definition of threatened or endangered under the Act.

In making this 90-day finding, we evaluated whether information regarding the threats to the smooth-billed ani, as presented in the petition and other information available in our files, is substantial, thereby indicating that the petitioned action may be warranted. Our evaluation of this information is presented below.

A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range

Information Provided in the Petition

The petition acknowledges that the smooth-billed ani's historic range in the United States has largely been restricted to southern Florida (Bent 1940; Terres 1980, p. 146) and that the species is considered common in many parts of its range throughout the Caribbean, including the Bahamas. The petition states that numerous records in the Dry Tortugas during the last 150 years indicate that the species is capable of traveling from Cuba to Florida (Birds of North America Online). The petition indicates that the species was reported in low numbers in Florida during the 1800s and early 1900s (Sprunt 1932; Bent 1940), with the first report of breeding in Florida in 1938 (Sprunt 1932; Terres 1980, p. 146). It also cites records from Louisiana and North Carolina dating back to the early 1800s (Bent 1940). The petition suggests that the species seems to have experienced an increase in population from the late 1950s through the early 1970s, and then a rapid decline from the 1970s to 2005. The petition claims that smooth-billed anis are extremely rare everywhere in the United States, noting data from various National Audubon Society Christmas Bird Counts.

The petition indicates that the species generally prefers “open” habitats, such as weedy and shrubby fields, pastures, farmland, and occasionally residential areas. Based upon a variety of unspecified sources, the petition states that the species is not commonly found in heavily forested or extensive marshes.

The petition states that rapid human population growth and associated development throughout peninsular Florida, much of it occurring within the species' preferred habitat and historic range, may be a potential contributor to the decline of the smooth-billed ani. The petition provides the following statement: “Apparently [the ani is] declining as southern Florida continues to develop, and the brushland shrub/scrub habitat is lost (Alsop 2002).” No additional information or citations relating to habitat loss as a threat are given in the petition.

Evaluation of Information Provided in the Petition and Available in Service Files

The smooth-billed ani appears to have declined from previous high levels in Florida (Stevenson and Anderson 1994, pp. 356-357; Mlodinow and Karlson 1999, p. 242; National Audubon Society 2005, pp. 1-3). However, it has been suggested that this species' current status in Florida may be the norm rather than an aberration (Mlodinow and Karlson 1999, p. 242). It was not until 1938 that the species was established and breeding in Florida (Sprunt 1939, pp. 335-336; Stevenson and Anderson 1994, p. 355). One hypothesis suggests that prior to the World War I era, south Florida had little suitable smooth-billed ani habitat, since it was largely a wetland surrounded by an inner zone of pine forests and outer zones of mangroves and sandy beaches (Mlodinow and Karlson 1999, p. 242). Substantial anthropogenic changes beginning in the 1920s, consisting of agricultural development and low-level residential development, may have created enough suitable habitat for dispersing anis to successfully colonize south Florida in the 1930s (Mlodinow and Karlson 1999, p. 242). Over time, residential development increased and more intensive agricultural practices and other factors may have reduced suitable habitat and dispersal habitat, causing decreased reproductive success and lower recruitment (Mlodinow and Karlson 1999, p. 242). Alsop (2002, p. 212) noted that the smooth-billed ani is apparently declining in south Florida as the area continues to develop and brushland shrub/scrub habitat is lost.

Information in our files supports the statement in the petition that human population growth and associated land-use changes are occurring in peninsular Florida, and that additional growth is expected in the future. In the 50 years prior to 1994, more than 8 million acres [(3.24 million hectares (ha)] of forest and wetland habitats (roughly 24 percent of the State) were cleared to accommodate an expanding human population (Cox et al. 1994, p. i). Statewide, between 1936 and 1987, cropland and rangeland increased by 4.25 million acres (1.72 million ha), or 30 percent; urban areas increased by 3.95 million acres (1.60 million ha), or 538 percent; herbaceous wetlands declined by 3.88 million acres (1.57 million ha), or 56 percent; and forests declined by 4.30 million acres (1.74 million ha), or 21 percent (Service 1999c, p. 4-128).

Although some anthropogenic habitat changes may initially favor this species, areas where the smooth-billed ani can be locally found in Florida, from the Keys north to West Palm Beach on the east coast and Collier County on the west coast (Mlodinow and Karlson 1999, p. 242), are expected to grow and become more urbanized. The human population within south Florida surpassed 1 million (337 persons per square mile (mi2) (130 persons per square kilometer (km2)) in 1950, 3 million (1,013 persons per mi2 (391 persons per km2)) in 1970, and 6 million (2,020 persons per mi2 (780 persons per km2)) in 1990 (Service 1999c, p. 4-127). South Florida's human population was projected to reach 8.2 million (2,771 persons per mi2 (1,070 persons per km2)) by 2010 (Floyd 1996 as cited in Service 1999c, p. 4-127). With continuing habitat loss and human Start Printed Page 23269population growth, it is likely that habitat within the smooth-billed ani's range in south Florida will continue to be impacted.

The petition did not contain information indicating that habitat loss and modification are threats to the smooth-billed ani elsewhere in its range (i.e., outside south Florida). Throughout its range, this species uses disturbed and human-altered rural and suburban areas, open areas with brush or scrub, plantations, gardens, farmlands, forest clearings, cow pastures, and grazing lands with human habitation (Loflin 1983 as cited in Quinn and Startek-Foote 2000, section 6, p. 1; Quinn and Startek-Foote 2000, section 6, p. 1). Although the landscape throughout the smooth-billed ani's considerable range is undoubtedly changing, we do not have evidence to suggest that the species is threatened by habitat loss and modification. In fact, ongoing disturbance of forest habitats by humans may create additional suitable habitat for smooth-billed anis, suggesting the possibility that populations are increasing within the range of the species (Quinn and Startek-Foote 2000, section 11, p. 3).

Information in the petition regarding rapid human population growth and associated development in Florida is supported by information in our files. Although increased habitat loss and human population growth may have affected the smooth-billed ani in south Florida, reasons for the expansion and contraction of its range in Florida are unclear. The species uses a wide array of disturbed and human-altered habitats (Quinn and Startek-Foote 2000, section 6, p. 1). Expansion in Florida may have temporarily been facilitated by anthropogenic habitat changes that initially favored this species; however, the species' current status in Florida may be the norm (Mlodinow and Karlson 1999, p. 242).

We currently have no information, and the petition provided no information, to support a determination that this factor is a substantial risk to the species in south Florida or elsewhere in its considerable range. In summary, we find that the information provided in the petition, as well as other information in our files, does not present substantial scientific or commercial information indicating that the petitioned action may be warranted due to destruction, modification, or curtailment of the smooth-billed ani's habitat or range, especially given that the species uses a wide array of disturbed habitats over a considerable range.

B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes

The petition did not present information, nor do we have information in our files, suggesting that overutilization is threatening the smooth-billed ani.

C. Disease or Predation

The petition did not provide any information concerning disease or predation. Information available in Service files does not report evidence of diseases. For instance, Quinn and Startek-Foote (2000, section 11, p. 2), found no reports of diseases for this species. Two species of mallophaga (bird lice) have been reported in the species (Davis 1940 as cited in Quinn and Startek-Foote 2000, section 11, p. 2). However, we do not have any information that ties these ectoparasites to any specific disease affecting the smooth-billed ani. Based upon limited information in Service files, disease is not considered to be a threat for the smooth-billed ani.

Evaluation of Information Provided in the Petition and Available in Service Files

The smooth-billed ani may be vulnerable to predators, because it is an awkward, slow-flying bird (Stevenson and Anderson 1994, p. 357). However, the species also employs a sentinel system, with usually one individual positioned at an open, elevated site to warn others of predators (Loflin 1983 as cited in Quinn and Startek-Foote 2000, section 9, p. 4). In addition, Merritt (1953 as cited in Stevenson and Anderson 1994, p. 357) has postulated that a very disagreeable odor given off when the bird is alarmed “probably tends to discourage predation.” Smooth-billed anis have been attacked or taken by sharp-shinned hawks (Accipiter striatus), fish crows (Corvus ossifragus), climbing rats (Rattus rattus), and feral cats (Felis catus) (Loflin 1983 as cited in Quinn and Startek-Foote 2000, section 9, p. 4; Startek 1997 as cited in Quinn and Startek-Foote 2000, section 9, p. 4; Quinn and Startek-Foote 2000, section 9, p. 4). In a limited study, Blanchard (2000, p. 45) noted a high incidence of egg and chick predation, documenting predation at 7 of 10 nests in Puerto Rico, most likely from brown rats (Rattus norvegicus) and feral cats. Predation rates are not available, but group vigilance likely limits diurnal predation to low levels (Davis 1940 as cited in Quinn and Startek-Foote 2000, section 11, p. 2).

In summary, disease is not known to be a threat to the species. Although information on predation within our files is limited, we do not have reason to believe that predation is a threat to the species. Accordingly, we find that the information in our files does not present substantial scientific or commercial information indicating that the petitioned action may be warranted due to disease or predation.

D. The Inadequacy of Existing Regulatory Mechanisms

The petition did not present information, nor do we have information in our files, suggesting that inadequacy of existing regulatory mechanisms is a threat to the species.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

Information Provided in the Petition

The petition suggests that one popular explanation for the smooth-billed ani's recent decline in Florida may have been periods of cold temperatures in south Florida; however, the petition also provides information that contradicts this explanation. Smooth-billed anis using the Clewiston area near Lake Okeechobee were reported to have survived subfreezing temperatures in the 1940s (reportedly 28 °F in 1944 and 26 °F in 1947) (Dilley 1948, p. 314). The petition suggests that the apparent increase in the smooth-billed ani's numbers during the late 1950s and early 1960s (National Audubon Society Christmas Bird Count data) coincides with two cold spells, but the beginning of the species' decline in the early 1970s does not correlate with a notable period of cold weather (McGovern 2004). The petition indicates that the severest cold weather to hit south Florida was during the 1980s, when smooth-billed ani populations continued to decline, but the species' decline had begun before this time.

The petition suggests that another explanation for this species' decline in Florida may be hurricanes, but this also does not seem to be reinforced by data. The petition indicates that smooth-billed ani populations increased from 1957 to 1974, when at least five hurricanes impacted south Florida. The petition indicates that as populations began to decrease in the 1970s and 1980s, south Florida was struck by only two hurricanes (Barnes 1998).

The petition, citing Birds of North America Online, suggests that possible ingestion of pesticides resulting from this species' insect diet is another explanation for its decline.Start Printed Page 23270

The petition suggests, without reference, that smooth-billed anis in the United States have undergone inexplicable natural population fluctuations for centuries and that no research has been conducted to investigate this phenomenon.

Evaluation of Information Provided in the Petition and Available in Service Files

The Service has only limited information regarding the possible effects of cold temperatures on the smooth-billed ani. The information regarding cold temperatures as a factor appears to be reliable based upon limited information in Service files. The decrease in numbers of smooth-billed anis in south Florida from the late 1970s through 1986 has been suggested to be due possibly to a series of unusually cold winters, which may have affected birds directly or indirectly through the reduction of the supply of insects (Stevenson and Anderson 1994, p. 357). Mlodinow and Karlson (1999, p. 242) acknowledged that a series of cold winters during the late 1970s likely played a role (citing Robertson and Woolfenden 1992), but suggested that a continued decrease in the population does not seem to be explained by weather alone. The petition does not present information, nor does the Service have information in our files, indicating that cold temperatures are a threat to the species elsewhere in its range.

The Service has little information regarding the possible effects of hurricanes on the smooth-billed ani. The petition acknowledges that data do not seem to reinforce the explanation that hurricanes caused declines in south Florida. Also, the petition does not present information indicating that hurricanes are a threat to the species elsewhere in its range. In Jamaica, the mean number of smooth-billed anis in 10 habitats before and after Hurricane Gilbert in 1988 was not significantly different (Wunderle et al. 1992, pp. 164-165). Similarly, no obvious decline in smooth-billed ani abundance was observed after Hurricane Georges in Puerto Rico in 1998 (Quinn and Startek-Foote 2000, section 11, p. 2). In general, stochastic (random) events are not likely to pose a significant threat to the smooth-billed ani, due to the species' considerable population size and geographic range.

The information provided in the petition regarding pesticides as a factor appears to be reliable, based upon limited information in Service files. Stevenson and Anderson (1994, p. 357) suggested that the smooth-billed ani's diet of insects could result in the ingestion of pesticides in the agricultural areas that the species often inhabits; they list this as an adverse factor that may have contributed to the smooth-billed ani's decrease in abundance in Florida from the late 1970s through 1986. Mlodinow and Karlson (1999, p. 242) suggested that pesticides may have also reduced food sources, and that this reduction was one possible factor contributing to the decline in Florida. Neither the petition nor the Service's files present information indicating that pesticides are a threat to the smooth-billed ani elsewhere in its range.

The Service has little information on natural population fluctuations of the smooth-billed ani in Florida or elsewhere in its range. The petition suggests, without reference, that smooth-billed anis in the United States have undergone inexplicable natural population fluctuations for centuries and that no research has been conducted to investigate this phenomenon. Based upon limited information in our files, it appears that the species has received relatively little research attention. More research is needed on the species' mating system and genetic relationships, reproductive and social behaviors, habitat quality, and foraging patterns (Quinn and Startek-Foote 2000, section 15, p. 1). Blanchard (2000, pp. 1-101) studied the communal breeding system of the species in Puerto Rico. The petition did not present information indicating that such natural population fluctuations are a threat to the smooth-billed ani elsewhere in its range. We have no additional information to suggest that demographic or other factors are a threat to the smooth-billed ani in Florida or elsewhere in its range.

Information provided by the petitioner regarding cold temperatures, hurricanes, pesticides, and natural population fluctuations is generally supported by the limited information in our files. However, we have no information or data that suggest that such factors are threats to the smooth-billed ani in south Florida or elsewhere in its range. In summary, we find that the information provided in the petition, as well as other information in our files, does not present substantial scientific or commercial information indicating that the petitioned action may be warranted due to natural or anthropogenic factors, especially given that the species appears to have a large population over a considerable range.

Finding

In summary, the petition does not present substantial information, because it does not provide specific information on threats to the smooth-billed ani and only alludes to possible threats within Florida, which is a small portion of the species' considerable range. Information in our files indicates that the smooth-billed ani has a large population size, uses a wide array of disturbed habitats, and occupies a considerable range. While we agree with the petitioner's general statements about possible causes for the species' recent decline in Florida, information in our files suggests that the species' current status in Florida may be the norm; the species was not known to breed in Florida prior to the late 1930s. Neither the petition nor our files contain information suggesting that threats affecting the species' continued existence occur elsewhere in its range.

As for the threats identified in this petition, we found no information to suggest that they are acting on the smooth-billed ani such that the species may become extinct now or in the foreseeable future.

On the basis of our determination under section 4(b)(3)(A) of the Act, we conclude that the petition does not present substantial scientific or commercial information to indicate that listing the smooth-billed ani under the Act as threatened or endangered may be warranted at this time. Although we will not review the status of the species at this time, we encourage interested parties to continue to gather data that will assist with the conservation of the smooth-billed ani. If you wish to provide information regarding the smooth-billed ani, you may submit your information or materials to the Field Supervisor/Listing Coordinator, South Florida Ecological Services Office (see ADDRESSES), at any time.

References Cited

A complete list of references cited is available on the Internet at http://www.regulations.gov or upon request from the South Florida Ecological Services Office (see FOR FURTHER INFORMATION CONTACT).

Author

The primary author of this notice is Paula Halupa of the South Florida Ecological Services Office (see ADDRESSES).

Authority

The authority for this action is the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

Start Signature
Start Printed Page 23271

Dated: April 13, 2011.

Rowan W. Gould,

Acting Director, U.S. Fish and Wildlife Service.

End Signature End Supplemental Information

[FR Doc. 2011-9975 Filed 4-25-11; 8:45 am]

BILLING CODE 4310-55-P