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the direct final notice of deletion, and Docket: All documents in the docket DEPARTMENT OF THE INTERIOR it will not take effect. We will, as are listed in the http:// appropriate, address all public www.regulations.gov index. Although Fish and Wildlife Service comments in a subsequent final deletion listed in the index, some information is notice based on this notice of intent to not publicly available, e.g., CBI or other 50 CFR Part 17 delete. We will not institute a second information disclosure of which is comment period on this notice of intent restricted by statute. Certain other [FWS–R6–ES–2008–0013; 1111 FY07 MO– B2] to delete. Any parties interested in material, such as copyrighted material, commenting must do so at this time. For will be publicly available only in hard Endangered and Threatened Wildlife additional information see the direct copy. Publicly available docket and Plants; 12-Month Finding on a final notice of deletion located in the materials are available either Petition To List the Gunnison’s Prairie Rules section of this Federal Register. electronically at http:// Dog as Threatened or Endangered DATES: Comments concerning this Site www.regulations.gov or in hard copy at must be received by March 6, 2008. the information repositories. AGENCY: Fish and Wildlife Service, Interior. ADDRESSES: Submit your comments, FOR FURTHER INFORMATION CONTACT: ACTION: identified by Docket ID No. EPA–HQ– Shawn Ghose M.S., P.E., Remedial Notice of a 12-month petition SFUND–1983–0002 Notice 4, by one of Project Manager (RPM), U.S. EPA finding. the following methods: Region 6 (6SF–RA), 1445 Ross Avenue, SUMMARY: We, the U.S. Fish and http://www.regulations.gov (Follow Dallas, TX 75202–2733, Wildlife Service (Service), announce our the on-line instructions for submitting [email protected] (214) 665–6782 12-month finding on a petition to list comments) or 800–533–3508. the Gunnison’s prairie dog (Cynomys E-mail: [email protected]. gunnisoni) as an endangered or Fax: 214–665–6660. SUPPLEMENTARY INFORMATION: For Mail: Donn Walters, Community additional information see the Direct threatened species under the Involvement, U.S. EPA Region 6 (6SF– Final Notice of Deletion located in the Endangered Species Act of 1973, as TS), 1445 Ross Avenue, Dallas, TX ‘‘Rules’’ section of this Federal Register. amended (Act). After a thorough review of all available scientific and 75202–2733, (214) 665–6483 or 1–800– Information Repositories: Repositories 533–3508. commercial information, we find that have been established to provide the species is not threatened or Instructions: Direct your comments to detailed information concerning this Docket ID No. EPA–HQ–SFUND–1983– endangered throughout all of its range, decision at the following locations: U.S. but that the portion of the current range 0002 Notice 4. EPA policy is that all EPA Region 6, 1445 Ross Avenue, Suite comments received will be included in of the species located in central and 700, Dallas, Texas 75202–2733, (214) south-central Colorado and north- the public docket without change and 665–6617, by appointment only Monday may be made available online at http:// central New Mexico (the northeastern through Friday 9 a.m. to 12 p.m. and 1 portion of the range) represents a www.regulations.gov, including any p.m. to 4 p.m.; Fort Smith Public personal information provided, unless significant portion of the range where Library, 3201 Rogers Avenue, Ft. Smith, the Gunnison’s prairie dog is warranted the comment includes information AR 72903, (479) 783–0229, Monday claimed to be Confidential Business for listing under the Act. Currently, through Thursday, 9 a.m. to 9 p.m., 9 listing is precluded by higher priority Information (CBI) or other information, a.m. to 6 p.m. Friday, 10 a.m. to 5 p.m. disclosure of which is restricted by actions to amend the Lists of Saturday and 1 p.m. to 5 p.m. Sunday; Endangered and Threatened Wildlife statute. Do not submit information that Arkansas Department of Environmental you consider to be CBI or otherwise and Plants. We have assigned a listing Quality (ADEQ), 5301 Northshore Drive, priority number (LPN) of 2 to this protected. The http:// North Little Rock, Arkansas 72118, (501) www.regulations.gov Web site is an species, because threats have a high 682–0744, Monday through Friday 8 magnitude, and are imminent. We will ‘‘anonymous access’’ system, which a.m. to 4:30 p.m. means EPA will not know your identity develop a proposed rule to list the or contact information unless you List of Subjects in 40 CFR Part 300 Gunnison’s prairie dog in the provide it in the body of your comment. northeastern (montane) portion of its Environmental protection, Air range as our priorities allow. If you send an e-mail comment directly pollution control, Chemicals, Hazardous to EPA without going through http:// DATES: This finding was made on waste, Hazardous substances, February 5, 2008. www.regulations.gov, your e-mail Intergovernmental relations, Penalties, ADDRESSES: address will automatically be captured Reporting and recordkeeping This finding is available on and included as part of the comment requirements, Superfund, Water the Internet at http:// that is placed in the public docket and pollution control, Water supply. www.regulations.gov and http:// made available on the Internet. If you www.fws.gov/mountain-prairie/species/ submit an electronic comment, EPA Authority: 33 U.S.C. 1321(c)(2); 42 U.S.C. mammals/gunnisonprairiedog. recommends that you include your 9601–9657; E.O. 12777, 56 FR 54757, 3 CFR, Supporting documentation we used to name and other contact information in 1991 Comp., p. 351; E.O. 12580, 52 FR 2923; prepare this finding is available for the body of your comment and with any 3 CFR, 1987 Comp., p. 193. public inspection, by appointment, disk or CD–ROM you submit. If EPA Dated: September 28, 2007. during normal business hours at the cannot read your comment due to Richard E. Greene, U.S. Fish and Wildlife Service, Western technical difficulties and cannot contact Regional Administrator, EPA Region 6. Colorado Field Office, 764 Horizon you for clarification, EPA may not be Drive, Building B, Grand Junction, CO able to consider your comment. Editorial Note: This document was 81506–3946; telephone (970) 243–2778; Electronic files should avoid the use of received at the Office of the Federal Register facsimile (970) 245–6933. Please submit special characters, any form of on January 30, 2008. any new information, materials, encryption and be free of any defects or [FR Doc. E8–1963 Filed 2–4–08; 8:45 am] comments, or questions concerning this viruses. BILLING CODE 6560–50–P finding to the above address.

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FOR FURTHER INFORMATION CONTACT: Al 12-month finding by February 1, 2008. disease (Antolin et al. 2002, p. 19; Pfister, Field Supervisor, U.S. Fish and The court adopted the terms and Biggins and Kosoy 2001, p. 911). Wildlife Service, Western Colorado conditions of the agreement on July 2, Complexes of Gunnison’s prairie dog Field Office (see ADDRESSES). If you use 2007. colonies (metapopulations) expand or a telecommunications device for the On August 28, 2007, we published a contract over time depending upon deaf (TDD), call the Federal Information notice initiating the 12-month finding various natural factors (such as Relay Service (FIRS) at 800–877–8339. and opening a 60-day public comment reproduction, food availability, and SUPPLEMENTARY INFORMATION: period on the Gunnison’s prairie dog (72 disease) and human-caused factors FR 49245). (such as chemical control and shooting). Background Species Information To substantially augment depleted Section 4(b)(3)(B) of the Act (16 populations or replace populations U.S.C. 1531 et seq.), requires that, for A description of the Gunnison’s without human intervention, a any petition containing substantial prairie dog is included in the 90-day metapopulation structure is required scientific and commercial information petition finding (71 FR 6241; February across the landscape so that migration that listing may be warranted, we make 7, 2006) and in a concise review of the between colonies is possible (Gilpin and a finding within 12 months of the date published information by Underwood Soule 1986, p. 24; Clark et al. 1982, pp. of receipt of the petition on whether the (2007, pp. 6–13). In addition, we used 574–575; Lomolino and Smith 2001, p. petitioned action is—(a) not warranted, data in the Western Association of Fish 938). (b) warranted, or (c) warranted, but that and Wildlife Agencies’ (WAFWA) Habitat immediate proposal of a regulation Gunnison’s Prairie Dog Conservation implementing the petitioned action is Assessment (Seglund et al. 2005) to Gunnison’s prairie dog habitat precluded by other pending proposals to complete much of our analysis in this includes level to gently sloping determine whether species are finding. grasslands and semi-desert and montane threatened or endangered, and whether The Gunnison’s prairie dog has shrublands, at elevations from 6,000 to expeditious progress is being made to sometimes been divided into two 12,000 feet (1,830 to 3,660 meters) add or remove qualified species from subspecies: Cynomys gunnisoni (Bailey 1932, p. 125; Findley et al. 1975, the Lists of Endangered and Threatened gunnisoni and C. g. zuniensis (Hollister p. 133; Fitzgerald et al. 1994, p. 183; Wildlife and Plants. Section 4(b)(3)(C) of 1916, p. 29). We currently regard the Pizzimenti and Hoffman 1973, p. 1; the Act requires that we treat a petition Gunnison’s prairie dog as a single Wagner and Drickamer 2002, p. 4). for which the requested action is found species because the most recent Grasses are the most important food to be warranted but precluded as though published analyses (Goodwin 1995, pp. item, with forbs, sedges, and shrubs also resubmitted on the date of such finding; 100, 101, 110; Pizzimenti 1975, pp. 11, occasionally used (Pizzimenti and that is, requiring a subsequent finding to 15, 63) do not support subspecies Hoffman 1973, p. 3; Shalaway and be made within 12 months. We must designation. Unpublished research Slobodchikoff 1988, p. 840). publish these 12-month findings in the (Hafner 2004, p. 6; Hafner et al. 2005, Gunnison’s prairie dog range can be Federal Register. p. 2) indicates that the distribution of considered to occur in two separate mitochondrial DNA (deoxyribonucleic range portions—higher elevations in the Previous Federal Actions acid) haplotype lineages supports past northeast part of the range and lower On February 23, 2004, we received a geographic isolation, followed by elevations elsewhere (Bailey 1932, pp. petition from Forest Guardians and 73 limited mixing in regions coincident 125–127; Pizzimenti and Hoffman 1973, other organizations and individuals with the recognized borders of the two pp. 1–2; Hall 1981, p. 7; Knowles 2002, requesting that the Gunnison’s prairie purported subspecies. Although this p. 4). We refer to these areas as montane dog (found in Arizona, Colorado, New analysis will likely be substantiated and prairie, respectively, throughout the Mexico, and Utah) be listed as through additional research, it is still document to differentiate them; threatened or endangered. preliminary and needs to be verified however, we recognize that these terms On July 29, 2004, we received a 60- before we can use it as evidence for are an oversimplification of the actual day notice of intent to sue for failure to subspecies designation. For the same habitats present, and describe them in complete a finding. On December 7, reasons, although Gunnison’s prairie more detail below. 2004, an amended complaint for failure dogs in montane habitat may be In Figure 1, we provide a map to complete a finding for this and other ‘‘markedly separate’’ from those in illustrating the division of the general species was filed. We reached a prairie habitat, we are not proposing range of the species into the settlement agreement with the plaintiffs, listing the montane prairie dogs as a northeastern (montane) and and on February 7, 2006, we published distinct population segment (DPS) southwestern (prairie) portions. The a 90-day finding in the Federal Register under our Policy Regarding the outer boundary in Figure 1 is referenced (71 FR 6241) determining that the Recognition of Distinct Vertebrate from maps depicting the species’ gross petition did not present substantial Population Segments Under the range (Hollister 1916, p. 24; Pizzimenti scientific information indicating that Endangered Species Act (61 FR 4722; and Hoffman 1973, p. 2; Pizzimenti listing the Gunnison’s prairie dog February 7, 1996). We anticipate that 1975, p. 4; Hall 1981, p. 415; Knowles species may be warranted. future funding may become available for 2002, p. 6), and from maps of the On August 17, 2006, Forest Guardians genetic, taxonomic, and range research species’ range in Arizona (Hoffmeister and eight other organizations and to determine whether subspecies or DPS 1986, p. 194), Colorado (Armstrong individuals provided written notice of status is valid. 1972, p. 139; Fitzgerald et al. 1994, p. their intent to sue regarding the Gunnison’s prairie dogs are a colonial 185), New Mexico (Findley et al. 1975, determination in the 90-day finding. On species, historically occurring in large p. 133), and Utah (Durrant 1952, p. 106). December 13, 2006, the plaintiffs filed a colonies over large areas. Colonial An approximate boundary dividing the complaint challenging the finding. On behavior offers an effective defense montane and prairie range portions was June 29, 2007, we reached a settlement mechanism by aiding in the detection of established from several maps that agreement with the plaintiffs for predators, but it also can play an recognize discrete range portions for submittal to the Federal Register of a important role in the transmission of each of the two purported subspecies,

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Cynomys gunnisoni gunnisoni and C. g. differences between Gunnison’s prairie portions vary in their age, projection, zuniensis (Hollister 1916, p. 24; dogs in the two range portions. Lastly, scale, and accuracy, and depict Armstrong 1972, p. 139; Pizzimenti and we used topographic maps to adjust the boundaries based on geography, Hoffman 1973, p. 2; Pizzimenti 1975, p. boundary on a finer scale along the morphological traits of Gunnison’s 4; Hall 1981). Maps that depict the mountain ranges and ridges of southern prairie dog populations, and genetic geographic variation in Gunnison’s Colorado and northern New Mexico, characteristics from Hafner’s work prairie dog mitochondrial DNA in because geography partly separates the (Hafner 2004, p. 6; Hafner et al. 2005, southern Colorado and northern New Gunnison’s prairie dog populations and p. 2). They contribute to the best Mexico (Hafner 2004, p. 6; Hafner et al. allows limited overlap between the two available information used to establish 2005, p. 2) were used to improve the range portions (Knowles 2002, p. 3; the montane and prairie portions of the resolution of the montane and prairie Hafner et al. 2005, p. 1). species’ range for further analysis. boundary in this region, as these maps In summary, the maps we used to provide a boundary based on genetic delineate the montane and prairie range BILLING CODE 4310–55–P

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BILLING CODE 4310–55–C

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Montane Habitat potential habitat occurs on private them comparable for determining long- The northeastern range (central and lands, 12 percent on State lands, 17 term population trends, while south-central Colorado, and north- percent on Federal lands, and 49 acknowledging potential error margins central New Mexico) consists primarily percent on Tribal lands/Bureau of on the scale of an order of magnitude. Since our 90-day finding in 2006, all of higher elevation, cooler and more Indian Affairs (BIA). The Tribal lands habitat occurs mostly in Arizona and States within the range of the species mesic plateaus, benches, and New Mexico; a large amount of potential have applied occupancy modeling intermountain valleys. We call this habitat is on Navajo lands (Cole, p. 1). methodology to investigate the habitat portion ‘‘montane’’ for ease of reference, Most estimates of prairie dog occupied by Gunnison’s prairie dogs. and it comprises approximately 40 populations in the available literature This is a newer technique that yields percent of the total potential habitat are expressed in terms of area (acres (ac) estimates of the percentage of random within the current range. Gunnison’s or hectares (ha)) of occupied habitat plots occupied across the habitat range prairie dogs occupy grass-shrub areas in rather than in numbers of individuals, under consideration (MacKenzie et al. low valleys and mountain meadows most likely because counting 2002, pp. 2248–2249; MacKenzie et al. within this habitat (Seglund et al. 2005, individuals is feasible only for small 2003, pp. 2200–2201). These estimates p. 12). The Gunnison’s prairie dogs in areas (Biggins et al. 2006, p. 94). Also, are statistically based and, therefore, are this portion of the range are limited by the number of animals present in a considered more objective (Andelt et al. pronounced physiographic barriers locality has been observed to vary with 2006, pp. 1–2; Colorado Division of (Pizzimenti and Hoffman 1973, p. 1), habitat, season, colony age, Wildlife (CDOW) 2007, p. 19; WAFWA including the Uncompahgre Plateau and precipitation, forage, predation, disease, 2007, p. 4). San Juan mountains in Colorado and chemical control, shooting, and other A drawback is that estimates of Utah, and the Sangre de Cristo, San factors (Knowles 2002, pp. 7–8); density percent occupancy by Gunnison’s Juan, and Jemez mountain ranges in of individuals typically ranges from 2 to prairie dogs are not directly comparable New Mexico. 23 per ac (5 to 57 per ha) (Fitzgerald et to estimates of occupied acres Prairie Habitat al. 1994, p. 184). Most prairie dog (including most historic estimates), surveys do not result in a density because when a random plot is visited, The southwestern range (southeastern estimate because of the associated effort only detection or non-detection (not Utah, southwestern Colorado, and cost. Estimates of Gunnison’s acres occupied) is recorded by the northwestern New Mexico, and prairie dog occupied habitat provide observers. If mapping is not performed northeastern Arizona) consists primarily one of the best available and most during a site visit, no information about of lower elevation, warmer and more reasonable means of evaluating the colony or complex size or location is xeric plains and plateaus (Bailey 1932, status of the species across its range. obtained. pp. 125–127; Pizzimenti and Hoffman Obtaining estimates of occupied area The positive aspects of this method 1973, pp. 1–2; Hall 1981, p. 7; Knowles is itself time-consuming and costly. are statistical rigor, precision estimates, 2002, p. 4). We call this portion Ground or aerial mapping of colonies large-scale application in a single ‘‘prairie’’ for ease of reference, and it over a predicted habitat range of 23 season, and trend analysis if performed comprises approximately 60 percent of million ac (9.5 million ha) in 4 States over subsequent years. In addition, the total potential habitat within the current would be required to determine a results of individual surveys can be range. Gunnison’s prairie dogs occupy rangewide estimate of the area occupied interpreted separately to assess prairie shortgrass and mid-grass prairies within by the Gunnison’s prairie dog (Seglund dog occupancy and document trends this habitat (Seglund et al. 2005, p. 12). et al. 2005, pp. 17–19). Recent attempts within in specific areas of concern. Distribution, Abundance, and Trends at less expensive aerial surveys (for Although only a single year (2007) of example, air photo interpretation) have occupancy modeling results are The current distribution of the species been limited in their effectiveness when available (with the exception of includes northeastern Arizona; central, applied to Gunnison’s prairie dogs Colorado data from 2005 and 2007), we south-central, and southwestern (Johnson et al. 2006, p. 3; Seglund et al. used these estimates, along with Colorado; north-central and 2005, pp. 23–24). Whether surveying is estimates of occupied areas, to assess northwestern New Mexico; and extreme performed from the air or on the ground, the status and trends of the Gunnison’s southeastern Utah (Bailey 1932, pp. it is often difficult to accurately and prairie dog in each of the four States. 125–127; Pizzimenti and Hoffman 1973, consistently discern colony boundaries Historical Estimates of Abundance pp. 1–2; Hall 1981, p. 7; Knowles 2002, (thus introducing error in the area p. 4) (see Figure 1 above). Limited measurements). Older studies did not Historical estimates of Gunnison’s overlap occurs in the ranges of benefit from technologies such as global prairie dog occupied habitat in Arizona Gunnison’s prairie dogs and black-tailed positioning systems and geographic and New Mexico are available from prairie dogs (Cynomys ludovicianus) in information systems (GIS) in mapping Federal records of early poisoning New Mexico (Goodwin 1995, p. 101; colonies. Accuracy suffers when studies efforts, such as by the Bureau of Land Sager 1996, p. 1), and Gunnison’s are performed over the longer time Management (BLM) and the U.S. Forest prairie dogs and white-tailed prairie intervals necessary to visit large range Service (USFS). In 1916, approximately dogs (Cynomys leucurus) in Colorado portions, because colony area, location, 6.6 million ac (2.7 million ha) of (Knowles 2002, p. 5), but we have no and persistence on the landscape often Gunnison’s prairie dog occupied habitat evidence that interbreeding is occurring. change relatively quickly (Wagner et al. occurred in Arizona, and 11 million ac Currently, 27 percent of potential 2006, p. 335). (4.4 million ha) occurred in New Gunnison’s prairie dog habitat occurs in In summary, we recognize that Mexico (Oakes 2000, pp. 169–171). In Arizona, 25 percent in Colorado, 45 different methodologies were used at our 90-day finding in 2006 (71 FR 6241, percent in New Mexico, and 3 percent different times and in different locales February 7, 2006), we calculated in Utah (Seglund et al. 2005, p. 83). We to derive the various historical occupied historical estimates (circa 1916) for used the data in Seglund et al. (2005, area estimates we obtained for review. Colorado (6 million ac (2.4 million ha)) pp. 82, 85–87) to calculate that These estimates contribute to the best and Utah (700,000 ac (284,000 ha)) from approximately 22 percent of the available information, and we consider prairie dog information in various

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publications and reports, because data metapopulation structure (prairie) and (3,617 ha) of inactive colonies; and were not available for these States. By that do not (montane). For example, the 171,970 ac (68,788 ha) of colonies in summation, based on the best available following paragraphs illustrate that unknown status within Colorado information, our rangewide estimate for Gunnison’s prairie dog occupancy in (CDOW 2007, p. 3). These data suggest historic (circa 1916) Gunnison’s prairie plots sampled in montane habitat is an increase over the historical 1961 dog occupied habitat was approximately estimated to be approximately 3.6 estimate of 115,650 ac (46,802 ha) of 24 million ac (9.7 million ha). percent as compared to approximately occupied habitat in Colorado. We have In 1961, an estimated 445,000 ac 18.3 percent in plots sampled in prairie no way of estimating what percent of (180,000 ha) of habitat was occupied by habitat in Colorado. Of the total this difference may be due to different Gunnison’s prairie dog in Arizona; montane habitat, approximately 85 mapping techniques. We believe that 116,000 ac (47,000 ha) in Colorado; percent occurs in Colorado. the difference is mostly due to an actual 355,000 ac (144,000 ha) in New Mexico; Arizona increase in prairie dogs, likely within and 100,000 ac (41,000 ha) in Utah the prairie portion of the range, because (Bureau of Sport Fisheries and Wildlife In 2007, occupied habitat on non- data from the montane portion of the 1961, pp. 1, 5). By summation, the Tribal lands in Arizona comprised range indicate significantly reduced rangewide estimate for Gunnison’s approximately 108,570 ac (40,500 ha) occupancy rates (see additional analysis prairie dog occupied habitat in 1961 (Underwood 2007, p. 30). No below). We used area estimates from was approximately 1 million ac comprehensive data are available from 2002 to 2005 to compute a Statewide (405,000 ha). These data suggest that, Tribal lands in Arizona, which include occupancy estimate of 2.1 percent from 1916 to 1961, Gunnison’s prairie 50 percent of the Statewide potential (known active colony area divided by dog populations decreased by habitat. Therefore, the 2007 estimate for area of potential habitat) (CDOW 2007). approximately 93 percent in Arizona, 98 Arizona (Underwood 2007, p. 30) is However, the occupancy modeling percent in Colorado, 97 percent in New likely substantially less than what studies performed in 2005 and 2007 in Mexico, and 86 percent in Utah, or by actually exists. Due to a lack of any Colorado, including both prairie and approximately 95 percent rangewide. Tribal estimates since 1961, recent montane portions of the range, yielded However, historic declines may not population trends on Tribal lands Statewide occupancy estimates of 7.5 support a conclusive inference that statewide are unknown, but may have and 8.6 percent, respectively (Andelt et current populations continue to decline. increased over the 1961 estimate of al. 2006, p. 15; CDOW 2007, p. 19), and In summary, empirical data on acres 435,419 ac (176,207 ha). We are these estimates are considered more unaware of any disproportionate occupied indicate that, between 1916 reliable. and 1961, habitat occupied by the adverse effects to the species on Tribal Gunnison’s prairie dog throughout its lands during this interval, and we Montane and Prairie Habitat in range declined from approximately assume that habitat trends may have Colorado 24,000,000 ac (9,700,000 ha) to followed a similar pattern as on non- Within Colorado, CDOW has approximately 1,016,000 ac (406,400 Tribal lands. All habitat within Arizona designated individual population areas ha). is considered prairie. to identify where Gunnison’s prairie Statewide Estimates of Abundance Colorado dogs exist and where management As indicated above, estimates of The Colorado Department of activities should be focused. The percent occupancy arrived at through Agriculture (CDA 1990, p. A–3) montane portion of the species’ range in recent occupancy modeling (presence or solicited questionnaire responses from Colorado is composed of the Gunnison, absence at a random plot) do not equate farmers and ranchers from which they San Luis Valley, South Park, and to acres occupied. The method currently extrapolated a 1990 estimate of Southeast population areas. By using used by States to assess the Gunnison’s 1,553,000 ac (621,200 ha) of occupied CDOW (2007, p. 28) estimates of prairie dog’s status, in conjunction with habitat for all 3 species of prairie dogs potential habitat, we determined that both historic and recent mapping found in Colorado (Gunnison’s, white- the montane range portion in Colorado efforts, provides empirical data on tailed, and black-tailed). Based on comprises about 80 percent (6.9 million percent occupancy of potential habitat. species occurrence by county, Seglund of 8.5 million ac (2.8 million of 3.4 This data is useful as a gross-scale et al. (2005, p. 26) estimated that million ha)) of the available Gunnison’s comparison to historical estimates of 438,876 ac (177,607 ha) were occupied prairie dog habitat in the State. acres occupied. Both types of data are by Gunnison’s prairie dogs. However, the montane range portion valid and represent the best available From 2002 to 2005, the Colorado only contains about 40 percent (73,861 science. Division of Wildlife (CDOW) of 182,237 ac (29,544 of 72,894 ha)) of Full occupancy of surveyed habitat interviewed field personnel from the available Gunnison’s prairie dog would not directly equate to 100 percent CDOW, the Service, the USFS, and the habitat occupied in the State, based on of available habitat, but it would BLM regarding the habitat occupied by our calculations using CDOW mapped provide a gross approximation of Gunnison’s prairie dogs in the State. area data (CDOW 2007, p. 3). occupancy at a larger geographic scale. Colonies were mapped on 1:50,000 scale The La Plata—Archuleta and For the purposes of interpreting the U.S. Geological Survey county sheets Southwest population areas, in the percent occupancy numbers in this and were designated as ‘‘active’’ (known prairie portion of Colorado’s Gunnison’s document, current State survey efforts to have prairie dogs inhabiting the prairie dog habitat, comprise about 20 utilize a scale from 1 to 100, indicating colony within the last 3 years); percent of the Gunnison’s prairie dog the percentage of occupied cells ‘‘inactive’’ (prairie dogs occurred in the habitat and contain about 60 percent of surveyed. Because we do not have area but have not been present in more habitat occupied in the State (CDOW historical data on percent of habitat than 3 years); or ‘‘unknown’’ (prairie 2007, pp. 3, 19). The higher proportion occupied or on occupancy rates, we use dogs were known to occur historically, of occupied habitat in the smaller the current percentage of occupied but current status was unknown). From prairie portion of the State indicates that habitat to compare between habitats that this effort, CDOW estimated 182,237 ac Gunnison’s prairie dogs are more currently appear to have a functional (72,895 ha) of active colonies; 9,042 ac abundant in the prairie habitat area.

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The 2005 occupancy modeling studies total acres in New Mexico, and therefore following five factors: (A) Present or also indicate a higher proportion of do not provide an acre estimate for the threatened destruction, modification, or occupancy (16 percent) in the prairie prairie portion. We have no data on the curtailment of habitat or range; (B) portion of the range in Colorado, and a percent occupancy in this habitat. overutilization for commercial, lower proportion of occupancy (3.2 recreational, scientific, or educational Utah percent) in the montane portion of the purposes; (C) disease or predation; (D) species’ range in Colorado (Andelt et al. The Utah Division of Wildlife inadequacy of existing regulatory 2006, p. 17; CDOW 2007, p. 19). When Resources estimated that 22,000 ac mechanisms; or (E) other natural or the study was repeated over the same (8,906 ha) of occupied Gunnison’s manmade factors affecting its continued plots in 2007, occupancy was again prairie dog habitat existed in Utah in existence. We evaluated whether threats found to be higher (18.3 percent) in the 1968 (Seglund et al. 2005, p. 35). to the Gunnison’s prairie dog may affect prairie portion and lower (3.6 percent) Knowles (2002, p. 21) estimated a its survival. Our evaluation of threats, in the montane range portion in minimum of 3,678 ac (1,490 ha) of based on information provided in the Colorado (CDOW 2007, p. 19). occupied habitat Statewide. The petition, available in our files, and Statewide trend in occupied habitat available in published and unpublished New Mexico appears to have decreased from 100,000 studies and reports, is presented below. We have no current information on ac (40,500 ha) in 1961 (Bureau of Sport A. The Present or Threatened occupied habitat in New Mexico. The Fisheries and Wildlife 1961, p. 5), to Destruction, Modification, or best available science is from 40,000 ac (16,000 ha) in 2007 (Lupis et Curtailment of its Habitat or Range Bodenchuck (1981 p. 1), who solicited al. 2007, p. 3). The Gunnison’s prairie questionnaire responses from dog occupancy in Utah was estimated to Agricultural land conversions agricultural producers in 1981. be 15.7 percent in 2007 (Lupis et al. historically had a significant impact on Respondents reported 107,574 ac 2007, p. 3). We consider all Gunnison’s Gunnison’s prairie dog habitat (Knowles (43,567 ha) of Gunnison’s prairie dog prairie dog habitat in Utah as prairie. 2002, p. 12). Gunnison’s prairie dogs occupied habitat. Bodenchuck (1981, p. have been displaced from some of the 8) extrapolated a Statewide total of Summary of Statewide Estimates of more productive valley bottomlands in 348,000 ac (141,000 ha) of occupied Abundance Colorado and New Mexico (Longhurst habitat for the species. Oakes (2000, p. We have empirical data on 1944, p. 36). Agriculture currently 216) questioned this extrapolation Gunnison’s prairie dog occupancy that impacts 2,063,930 ac (834,243 ha), or because of possibly faulty assumptions indicate a large decline in rangewide less than three percent, of the used to derive it. Knowles (2002, p. 22) occupied acres. We also have recent Gunnison’s prairie dog range (Seglund estimated that 75,000 ac (30,000 ha) of empirical data that indicates percent et al. 2005, p. 43). Seglund et al. (2005, occupied habitat existed in 1982. New occupancy within two separate portions p. 41) indicate agriculture is not a major Mexico Department of Game and Fish of the range is significantly different. rangewide threat because of the small used Digital Orthophoto Quarter Data on acres occupied indicate that percentage of the range affected, but also Quadrangles to estimate a minimum of between 1916 and the present, habitat because agriculture provides highly 9,108 ac (3,689 ha) of occupied habitat occupied by Gunnison’s prairie dogs productive forage in place of the native Statewide in 2004 (Seglund et al. 2005, throughout its range declined from arid landscape. Current adverse impacts p. 23). However, this method appears to approximately 24,000,000 ac (9,700,000 relate to secondary actions at a local be hampered by inaccurate detection of ha) to between 340,000 and 500,000 ac scale, such as prairie dog control (for disturbances, time elapsed since (136,000—200,000 ha). This represents a example, poisoning, shooting) in areas photography, time elapsed since ground rangewide decline of greater than 95 where prairie dogs occupy lands used mapping, temporal changes in prairie percent. for agriculture, particularly private dog towns, and other factors (Seglund et lands. We assess shooting under Factor al. 2005, p. 33). While these estimates Summary of Factors Affecting the C, poisoning under Factor E, and both have limited accuracy, general use in Species Rangewide in Factor D. assessing Statewide occupied habitat Section 4 of the Act (16 U.S.C. 1533) Urbanization also has caused habitat indicates that Gunnison’s prairie dogs and implementing regulations at 50 CFR loss for Gunnison’s prairie dog. Seglund appeared to be decreasing between 1961 424, set forth procedures for adding et al. (2005, p. 41) determined that and 2004. species to the Federal Lists of urbanization affects 577,438 ac (233,681 Endangered and Threatened Wildlife ha) within the range of the species (less Montane and Prairie Habitat in New and Plants. In making this finding, we than two percent of the range). Mexico summarize below information regarding However, it appears this analysis New Mexico also includes both the status and threats to the Gunnison’s considered only the direct effects of montane and prairie habitat. The prairie dog in relation to the five factors habitat loss. Urbanization also exerts montane habitat is geographically provided in section 4(a)(1) of the Act. indirect effects (for example, poisoning connected to the montane portion of the In making this 12-month finding, we and shooting of prairie dogs), extending Gunnison’s prairie dog habitat in have considered all scientific and a human ‘‘disturbance zone’’ outward Colorado. It comprises about 17 percent commercial information received or from the actual development footprint. of the Gunnison’s prairie dog habitat in acquired between the time of the initial Lower-density suburban development New Mexico; we do not have accurate petition (February 23, 2004) and the end occurring in the southern Rocky data on total acres in New Mexico, and of the most recent public comment Mountains is scattered and results in a therefore do not provide an acre period (October 29, 2007), and fragmenting of habitats. In Colorado, estimate for the montane portion. We additional scientific information from urban development on the west slope of have no data on the percent occupancy ongoing species surveys and studies as the Rocky Mountains (montane habitat) in this habitat. they became available. is occurring rapidly; 38 percent of The prairie habitat in New Mexico Under section (4) of the Act, we may Gunnison’s prairie dog range is comprises about 83 percent of the determine a species to be endangered or predicted to be impacted by low urban habitat; we do not have accurate data on threatened on the basis of any of the development (less than 40 units per ac;

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99 per ha), 6 percent by moderate information is available that quantifies B. Overutilization for Commercial, development (40 to 80 units per ac; 99 the amount of occupied habitat affected. Recreational, Scientific, or Educational to 198 per ha), and 5 percent by high In a study of white-tailed prairie dogs, Purposes development (fewer than 80 units per Menkens and Anderson (1985, p. 13) Gunnison’s prairie dogs have been ac) between 2000 and 2020 (CDOW concluded that any impact from seismic historically subjected to recreational 2007, p. 28). We do not have testing is negligible. However, we shooting and shooting as a form of pest information on the extent of acknowledge that oil and gas management on ranch and agricultural development projected to occur in the development is rapidly occurring land; these practices continue under other States within the species’ range (Seglund et al. 2005, p. 44), and that this current State regulations (see Factor D. (Utah, Arizona, and New Mexico). potential threat should be considered Inadequacy of Existing Regulatory Potential threats to Gunnison’s prairie more closely when more accurate data Mechanisms). Prairie dogs are especially dog populations due to urban and are available. vulnerable to shooting due to their Road-related Gunnison’s prairie dog suburban development exist, but have colonial behavior, which facilitates easy not been quantified, in the four cities of mortality exists in proximity to specific access to many individuals at once Santa Fe and Albuquerque, New population areas. Roads may be (Seglund et al. 2005, p. 48). Most field Mexico; Flagstaff, Arizona; and increasing due to oil and gas studies on the effects of shooting prairie Gunnison, Colorado (CDOW 2007, p. 4). development. However, no studies dogs have been carried out on black- In some areas, Gunnison’s prairie dogs quantify road mortality of Gunnison’s tailed prairie dogs, but we consider the threatened by urban development have prairie dogs. We have no data indicating results relevant to Gunnison’s prairie been captured and relocated to that roads are currently threatening the dogs (CDOW 2007, p. 41). Shooting preserves or other nearby habitats, species rangewide, and we conclude effects include population reduction mitigating effects to overall population that prairie dog populations are able to and alteration of behavior, such as numbers, but not to area of habitat. recover from individual losses due to Although urban and suburban road mortality. decreased foraging rates and increased development exert adverse impacts on Conservation principles indicate that vigilance, which reduce individual Gunnison’s prairie dog populations at a smaller, more isolated populations are prairie dog vigor and result in lower local scale, they likely affect less than more vulnerable to extirpation (Barnes reproductive output (Knowles 1988, p. three percent of the species’ range; low 1993, p. 34; Cully 1993, p. 43; Fitzgerald 54; Reeve and Vosburgh in press, p. 5; density development appears to be 1970, p. 78; Gilpin and Soule 1986, pp. Vosburgh 1996, pp. 32–33; Vosburgh compatible with continued use by 30–31; Miller et al. 1994, p. 151; and Irby 1998, p. 368; Pauli and Buskirk prairie dogs, due to the offsets provided Mulhern and Knowles 1995, p. 21; 2007, pp. 1223–1224). by lawns and pastures that provide high Wilcox and Murphy 1985, p. 883; Recreational shooting can reduce quality forage (Seglund et al. 2005, p. Wuerthner 1997, p. 464). Lomolino et prairie dog population density at 41). al. (2003, p. 116) found that persistence specific sites (Knowles 2002, p. 14; Noxious weeds can increase in the of Gunnison’s prairie dog colonies Miller et al. 1993, p. 91; Vosburgh 1996, presence of livestock overgrazing, and a increased significantly with larger pp. 13–14; Vosburgh and Irby 1998, pp. relationship likely exists between colony size and decreased isolation. 366–367). Local extirpation of colonies overgrazing, Bromus tectorum (cheat However, we found no studies or data may have occurred in isolated grass) proliferation, and increased fire that specifically assess the magnitude of circumstances in the past (Knowles frequency and intensity (Seglund et al. the threats discussed under Factor A 1988, p. 54). However, increased 2005, p. 43). However, we have no data (agriculture land conversions, population growth rates or recovery that quantifies these factors or their urbanization, grazing, roads, and oil and from very low numbers following correlation with effects to Gunnison’s gas leasing) and resulting fragmentation shooting also have been reported prairie dog populations. The impact of throughout the range of Gunnison’s (Knowles 1988, p. 54; Reeve and overgrazing on prairie dog populations prairie dog habitat. Vosburgh in press, p. 7). Recent studies is contradictory. Some reports have of the effects of shooting on black-tailed Summary of Factor A noted that species density is positively prairie dogs appear to contradict the correlated with the number of native After assessing the best available idea that populations quickly rebound plants (Slobodichikoff et al. 1988, p. science on the magnitude and extent of from shooting. Reproductive output on 406), and that grazing has decreased the effects of agricultural land colonies subjected to shooting decreased forage availability (Seglund et al. 2005, conversion, urbanization, grazing, roads, by 82 percent, while control colonies p. 42). Other reports have concluded oil and gas development, and maintained a stable reproductive rate that prairie dog density is positively fragmentation of habitat, we find that over the same period (Pauli and Buskirk correlated with an increase in grazing, the destruction, modification, and 2007, p. 1228). Therefore, black-tailed which simulates the shortgrass-type of curtailment of Gunnison’s prairie dog’s prairie dogs do not appear to rebound prairie environment preferred by prairie habitat or range are not significant quickly from shooting. dogs (Fagerstone and Ramey 1996, p. 88; threats. Agriculture, urbanization, roads, The International Union for the Marsh 1984, p. 203, Slobodchikoff et al. and oil and gas development each Conservation of Nature/Species Survival 1988, p. 406). Considering the currently affect a small percentage of Commission (IUCN/SSC) Conservation conflicting conclusions of published Gunnison’s prairie dog habitat. Effects Breeding Specialist Group evaluated the literature, and the lack of large-scale of livestock grazing, while widespread, effects of shooting mortality on population decreases due to habitat have not resulted in measurable population viability of Gunnison’s alterations from livestock grazing, we population declines. However, we need prairie dogs (CDOW 2007, p. 124). find this is not a significant threat to the more information on the impacts of Simulations were run with a shooting Gunnison’s prairie dog. fragmentation and isolation with regard closure in place from March 1 through Numerous land parcels within the to persistence of prairie dog populations June 14 each year (approximating State Gunnison’s prairie dog range are leased and on the magnitude of the potential closures) and without any closures. for oil and gas development (Seglund et threat posed by increasing oil and gas Having the closure in place resulted in al. 2005, pp. 36, 42). However, no development. positive population growth and

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negligible risk of extinction, except in and rarely by inhalation of infectious or complete recovery following scenarios with the highest levels (20 respiratory droplets from another population reductions due to plague percent) of shooting-based mortality. animal (Gage et al. 1995, pp. 695–696). have been reported for both white-tailed Simulations run without the seasonal Plague was first observed in wild and black-tailed prairie dogs (Cully shooting closure in place suggest that rodents (termed sylvatic plague) in 1993, pp. 40–41), but little to no when initial population sizes are North America near San Francisco, recovery has been noted in montane smaller (less than 250 individuals) and California, in 1908 and was detected in Gunnison’s prairie dog colony die-offs, shooting mortality is high (20 percent), Gunnison’s prairie dogs in the 1930s even after long periods of time a decrease in growth rate and an (Eskey and Hass 1940, p. 6). Plague has (Capodice and Harrell 2003, pp. 5–7; increase in population extinction risk subsequently spread so that it now Cully et al. 1997, p. 717; Lechleitner et exist (CDOW 2007, pp. 135–137). encompasses the entire range of the al. 1968, p. 734). Possible long-term Colorado, Utah, and Arizona (outside species (Centers for Disease Control consequences of continued plague Tribal lands) have implemented 1998, p. 1; Cully 1989, p. 49; Girard et infection in Gunnison’s prairie dog seasonal closures on prairie dog al. 2004, p. 8408). Therefore, it has only populations may be: shooting. In Arizona and New Mexico, been present within the species’ range (1) local extirpation of colonies; the Navajo Nation monitors this threat for approximately 70 years, allowing (2) reduced colony size; but currently implements no closures on very little time for any resistance to (3) increased variance in local shooting because it finds the level of evolve (Biggins and Kosoy 2001, p. 913). population sizes, and shooting to be low on its lands (Cole Once established in an area, plague (4) increased inter-colony distances 2007, p. 4). becomes persistent and periodically (CDOW 2007, p. 43). erupts, with the potential to eventually Summary of Factor B The factors that influence extirpate or nearly extirpate entire interspecific (between species) We have determined that shooting colonies (Barnes 1982, p. 255; Barnes transmission of plague from mammalian continues to be a threat to the 1993, p. 28; Cully 1989, p. 51; Cully et Gunnison’s prairie dog throughout all of or avian reservoirs (for example, al. 1997, p. 711; Fitzgerald 1993, pp. coyotes, raptors, corvids) into prairie its range and contributes to the decline 52–53). The term ‘‘enzootic’’ describes of the species when combined with the dog populations are unclear, but seem to plague existing at a less severe level, be primarily through fleas that could effects of disease (see Factor C below). sometimes referred to as a However, this threat is being monitored increase in moister climates (Parmenter ‘‘maintenance’’ condition, that is et al. 1999, p. 818; Rayor 1985, p. 195). and managed in all States and the present continuously throughout a Navajo Nation, and modeling results However, interspecific transmission species’ habitat; the term ‘‘epizootic’’ does not seem to be a significant factor suggest seasonal shooting closures describes a severe plague outbreak or creating plague epizootics. Plague is implemented in Colorado and Arizona amplification transmission cycle (Gage now considered enzootic throughout the will likely reduce population-level et al. 1995, p. 696). losses. Therefore, we have determined Prairie dogs are highly susceptible to range of the Gunnison’s prairie dog. that overutilization for commercial, plague, and this susceptibility is The primary factor influencing plague recreational, scientific, or educational thought to be a function of high enzootics in Gunnison’s prairie dogs is purposes is not a significant threat to population densities, abundant flea thought to be abundance of fleas within the Gunnison’s prairie dog. vectors, and uniformly low resistance their own colonies. This appears to be correlated with seasonal moisture in C. Disease or Predation (Biggins and Kosoy 2001, p. 913). Gunnison’s prairie dogs can experience specific habitat areas. Plague outbreaks While prairie dogs are prey to mortality rates of greater than 99 percent may be triggered by climatic conditions, numerous species, including coyotes, during epizootics, and eradication of such as mild winters and moist springs badgers, black-footed ferrets, and populations can occur within one active (Parmenter et al. 1999, p. 818; Rayor various raptor species, there is no season (Lechleitner et al. 1962, pp. 190– 1985, p. 195). Enscore et al. (2002, p. information available to indicate that 192; Lechleitner et al. 1968, p. 736; 191) found a close relationship between predation has an overall adverse effect Rayor 1985, p. 194; Cully 1989, p. 49). human plague cases in the southwestern on the species. Black-footed ferrets have Oral vaccination through United States and high amounts of late been reintroduced into two locations in consumption of vaccine-laden baits spring (February to March) precipitation Arizona, including the Aubrey Valley, could reduce mortality from plague. (time-lagged 1 and 2 years) and where Gunnison’s prairie dog Mencher et al. (2004, pp. 5504–5505) maximum daily summer temperature populations appear to be stable. report protection against plague in values in the moderately high range (85 The Gunnison’s prairie dog is, black-tailed prairie dogs, elicited to 90 °F; 29 to 32 °C). however, affected by sylvatic plague, through voluntary consumption of a Girard et al. (2004, p. 8408) which occurs in regular outbreaks and vaccine-laden bait in the laboratory. The postulated that when resistant hosts of causes population declines and vaccine has been shown to be safe in plague encounter a susceptible species extirpations. Plague is an exotic disease numerous animals including black- that is plague naı¨ve and has a high foreign to the evolutionary history of footed ferrets, raccoons, skunks, population density, an epizootic occurs. North American species (Barnes 1982, bobcats, cats, dogs, and sheep. However, During epizootic phases, declines in p. 238; Barnes 1993, p. 29; Biggins and future field trials are required to test the abundance of susceptible species like Kosoy 2001, p. 907). This flea-borne efficacy on the Gunnison’s prairie dog. prairie dogs are observed (Hanson et al. disease, caused by infection with the Recovery rates of Gunnison’s and 2007, p. 790). The rapid dispersal of the bacterium Yersinia pestis, is shared by Utah prairie dog colonies studied 2 pathogen through an area can be humans and other vertebrate animals. years post-epizootic found that followed by an enzootic phase, a slower Rodents are the primary vertebrate hosts Gunnison’s prairie dog colonies transmission cycle that disperses of Y. pestis, but other mammals can be experienced 100 percent mortality and through the lower-density, more infected. Y. pestis is transmitted to remained depopulated throughout the resistant hosts remaining from the first mammals by bites of infected fleas, study due to the lack of available cycle. This establishes the disease in direct contact with infected animals, immigrants (Turner 2001, p. 14). Partial stable reservoirs for future emergence

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(Girard et al. 2004, p. 8413; Gage and from one individual to another (Antolin a Gunnison’s prairie dog colony in Kosoy 2005, pp. 506–509). et al. 2002, p. 19; Cully 1989, p. 49; Colorado that killed all members of the Enzootic infection is generally Cully and Williams 2001, p. 901; Turner colony. Prior to the outbreak, this considered characteristic of a stable 2001, p. 31). Biggins (2003, p. 6) colony had been continuously occupied rodent–flea infectious cycle where host speculated that if transmission rates for for 20 years, despite several poisoning rodents are relatively resistant to the plague are at least partly dependent on attempts. Two years after the plague disease. However, Hanson et al. (2007, host density, prairie dog populations on outbreak, the colony still had not been p. 792) found that an unexpectedly high good quality sites may undergo both recolonized, likely because it was percentage of black-tailed prairie dog larger declines and more rapid isolated from other colonies by 8 mi (13 colonies in Montana tested positive for recoveries than those on poor sites. km) (Lechleitner et al. 1962, p. 187). plague. They speculate that, under some Available literature is inconclusive Research is underway on the efficacy conditions, black-tailed prairie dogs, regarding whether isolation or density of insecticides in protecting various rather than acting as resistant hosts, may of a colony affects the number and prairie dog species from plague. Biggins serve as enzootic hosts or carriers of the frequency of plague outbreaks. and Godby (2005, p. 2) hypothesized pathogen. Plague antibody titers Lomolino et al. (2003, p. 118) and others that if enzootic plague is affecting (concentrations in blood) have been (Cully and Williams 2001, p. 901; Miller populations of prairie dogs, an found in small numbers of Gunnison’s et al. 1993, pp. 89–90) suggested that ambitious effort to remove the disease prairie dogs in New Mexico, indicating isolation and fragmentation may should result in increased survival rates individual exposure to plague and provide some protection to prairie dogs of prairie dogs. Fleas in Utah prairie dog subsequent recovery (Cully et al. 1997, from plague by lessening the likelihood burrows were effectively controlled by p. 717; Cully and Williams 2001, p. of disease transmission. However, this annual treatments of the insecticide 898). Plague appears to have had little theory no longer applies when plague is deltamethrin; fleas were reduced 96 to effect on a Gunnison’s prairie dog enzootic throughout the range of 98 percent within one month of population in Aubrey Valley, Arizona Gunnison’s prairie dog (as it appears to treatment (Biggins and Godby 2005, p. (Wagner and Van Andelt 2007, p. 2). be), in which case isolation of colonies 5). Studies of the effects of flea control However, little evidence of resistance to reduces the chance of recolonization on black-tailed and white-tailed prairie plague has been found in any species of after extirpation (Wagner and Drickamer dogs have shown similar results prairie dog at this time. 2002, p. 16; Lomolino and Smith 2001, (Biggins 2007). At this time, chemical In conducting a Population Viability pp. 942–943). In areas where dusting of individual prairie dog Analysis on Gunnison’s prairie dogs, the Gunnison’s prairie dog colonies are burrows is labor intensive and IUCN/SSC Conservation Breeding located close to each other (less than 6 expensive. Specialist Group (CDOW 2007, p. 123) miles (mi) (10 kilometers (km) apart), All recent, major Gunnison’s prairie hypothesized that in an enzootic inter-colony dispersal of plague is likely dog colony declines documented in scenario, plague operates at a relatively through infected prairie dogs (Girard et published literature have been low level each year, thereby increasing al. 2004, p. 8412). For colonies attributed to plague epizootics. average annual rates of mortality above separated by long distances or However, the magnitude of the plague what would occur in a more benign unsuitable habitats, infection may occur threat appears to be different in the non-enzootic scenario. due to long-distance dispersal of plague- montane and prairie portions of the Gunnison’s prairie dog populations infected fleas by domestic dogs, coyotes, Gunnison’s prairie dog range. are more susceptible to decline from raptors, or other predators and Population declines in prairie habitat plague than white-tailed prairie dog scavengers (Barnes 1993, p. 34), or are less dramatic than those in montane populations and are at least as, if not plague may already persist as enzootic habitat; partial recovery or more, susceptible than black-tailed throughout Gunnison’s prairie dog establishment of new colonies have prairie dog populations (Antolin et al. range. been documented following plague in 2002, p. 14; Cully 1989, p. 51; Cully and The impacts of plague outbreaks, the prairie range portion, but are rare or Williams 2001, p. 899; Hubbard and which lead to the loss of prairie dog absent following plague outbreaks in the Schmitt 1983, p. 51; Knowles 2002, p. colonies of all sizes (Roach et al. 2001, montane range. 13; Ruffner 1980, p. 20; Torres 1973, p. p. 956), are magnified by isolation of We reviewed literature on the status 31; Turner 2001, p. iii). Gunnison’s colonies. Colony growth after an of Gunnison’s prairie dog populations prairie dogs commonly forage outside of epizootic is mainly the result of within the two portions of the range their home territory, a characteristic that recolonization by inter-colony and, specifically, all published and may play a significant role in the dispersers (Antolin et al. 2002, p. 17). unpublished literature on the effects of susceptibility of the species to plague. Wagner et al. (2006, pp. 334–335) plague on prairie dogs. While some The Gunnison’s prairie dog may be studied cycles of extirpation and studies were not recent, summarizing more susceptible to plague than the recolonization in Gunnison’s prairie them below provides background on the black-tailed prairie dog because of the dogs in Arizona, including a large responses of Gunnison’s prairie dog Gunnison’s less exclusive territorial number of colonies over a large populations to plague in each portion of behavior (many mix relatively freely geographic area, and found a significant the range. throughout adjacent territories) and relationship between the persistence of thereby contribute to the colonies and the persistence of their Effects of Plague in Montane Habitat communicability of plague (Hoogland nearest neighboring colony. Increased Several well-studied colonies within 1999, p. 8). isolation decreases the likelihood of the montane portion of the Gunnison’s The Gunnison’s prairie dog is also recolonization following a plague prairie dog range have been documented likely more susceptible to plague than outbreak if the distance between the as being extirpated, or nearly so, due to the white-tailed prairie dog because the infected colony and the next nearest plague. The South Park, Colorado, Gunnison’s typically occurs at higher colony is beyond the dispersal population area included estimated densities and is less widely dispersed capabilities of the species. For example, occupied habitat of 915,000 ac (371,000 on the landscape, allowing for more Lechleitner et al. (1962, pp. 195, 197) ha) in 1945; 74,000 ac (30,000 ha) in frequent transmission of the disease documented a 1959 plague outbreak in 1948; and 42 ac (17 ha) in 2002 (CDOW

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2007). This decline was largely due to 2006 and 2007. Four other large decline in persistence takes place plague and affected a substantial portion colonies in the same vicinity were (Lomolino and Smith 2001, p. 942). of the species’ extant occupied habitat active in 2006, but by 2007, no prairie The landscape status in the montane in Colorado (at least 15 percent). A dog activity was observed. Plague is the portion of Gunnison’s prairie dog range plague event in Saguache County, suspected cause of these extirpations, is characterized by fewer, smaller Colorado, that progressed across seven because of the complete elimination of colonies that are isolated, and few to no colonies in 2 years left only scattered the prairie dogs with no sign of complexes or metapopulation structure. individuals surviving in two colonies poisoning (CDOW 2007, p. 4). Isolation of populations is related to the (Lechleitner et al. 1968, p. 734). In Fitzgerald (1993, p. 52) expressed montane geography in this portion of Gunnison, Saguache, and Montrose concern about the status of the the range. Gunnison’s prairie dogs Counties, Colorado, plague also was Gunnison’s prairie dog in Colorado, occupy low valleys and mountain responsible for a decline from 15,569 ac indicating that plague had eliminated meadows within this habitat (Seglund et (6,228 ha) of occupied habitat in 1980, many populations, including almost all al. 2005, p. 12), likely because the short to 770 ac (308 ha) in 2002 (note that of the populations in South Park. He growing season at elevations higher than Montrose County is in the Southwest also suggested that populations 10,000 ft (3,048 m) limits forage (Andelt population area in prairie habitat) appeared to be in poor condition in the et al. 2006, p. 17). In addition, mountain (Capodice and Harrell 2003, pp. 5–7). A San Luis Valley, and were extirpated topography minimizes the zone of complete die-off of a colony due to from the extreme upper Arkansas River contact between populations (Knowles plague in Chubbs Park, Chaffee County, Valley, as well as Jefferson, Douglas, 2002, p. 3). At least four mountain Colorado, occurred in 1959 (Lechleitner and Lake Counties. These areas ranges within the montane portion of et al. 1962, p. 185). In August 1958, the comprise most of the Gunnison’s prairie the range act as barriers to Gunnison’s population was stable and healthy, but dog montane habitat in Colorado. prairie dog dispersal (Pizzimenti and During 1984 through 1987, a plague in 1959 an epizootic spread 2 mi (3 km) Hoffman 1973, p. 1). These factors make event reduced the population of within 3 months; prairie dogs continued the prairie dogs in this habitat highly Gunnison’s prairie dogs in the Moreno to be absent from the area in 1960 and susceptible to plague-related declines, Valley of New Mexico from more than 1961, and we have no recent and we have no evidence of long-term 100,000 individuals to between 250 and information on the existence of prairie recovery from plague in the montane 500, a decline of greater than 99 percent dogs in that location. Plague resulted in habitat area. the complete loss, over a 2-year period, (Cully et al. 1997, pp. 708–711). of a colony in South Park, Colorado Although the growth rate of the Effects of Plague in Prairie Habitat remaining population increased (Fitzgerald 1970, pp. 68–69). The Southwest and the La Plata- Approximately 1,000 to 1,500 following the epizootic, another plague Archuleta populations in Colorado are Gunnison’s prairie dogs were killed by event swept through the area in 1988, within the prairie portion of Gunnison an outbreak of plague in a 148-ac (60- and the population in July 1996 was prairie dog range. The Southwest ha) colony in Curecanti National still ‘‘a fraction’’ of what it had been in population comprises the largest Recreation Area near Gunnison, 1984 (Cully et al. 1997, p. 718). population of Gunnison’s prairie dogs in Colorado, in 1981 (Rayor 1985, p. 194). Occupancy modeling performed in Colorado, with an estimated 88,267 ac A few animals survived the disease and Colorado in 2005 indicated a lower (35,307 ha) of active colonies. Currently, Gunnison’s prairie dogs were again proportion of occupancy in the montane abundant in the area in 1986 (Cully portion of the species’ range within prairie dogs can be found in nearly any 1989, p. 49). In 2002, 252 ac (102 ha) of Colorado (3.2 percent) than in the habitat suitable for occupation, although habitat in the Recreation Area were prairie portion within Colorado (16.0 densities are low to very low in native occupied by Gunnison’s prairie dog percent) (Andelt et al. 2006, p. 17; rangeland areas. Plague may be a colonies (Capodice and Harrell 2003, p. CDOW 2007, p. 19). When the study problem in this area, because periodic 23), but the current estimate is 12 ac (4.8 was repeated over the same plots in die-offs not associated with poisoning or ha) (Childers 2007, p. 2). Colonies 2007, occupancy was again found to be other control measures have been noted within the Recreation Area experienced lower (3.6 percent) in the montane range by local farmers and ranchers in the six plague epidemics between 1971 and portion in Colorado than in the prairie past. However, unlike populations in 2007. Of the 9 historic Gunnison’s portion (18.3 percent) (CDOW 2007, p. montane habitat within Colorado, these prairie dog colonies, 3 are currently 19). The only recent threat responsible populations appear to rebound from active, and 2 act as source populations for whole population declines and periodic epizootics (CDOW 2007, p. 16). for the main prairie dog concentration extirpations, as documented in the Populations in the La Plata-Archuleta area (Childers 2007, p. 1). If the source studies cited in this section, is plague. population area appear to undergo colonies die off due to plague, The frequency of plague epizootics plague outbreaks every 4 to 7 years, repopulation may not be possible appears to be high in montane habitat which may be limiting some because any other Gunnison’s prairie due to moister environmental populations (CDOW 2007, p. 7). dog populations remaining will be conditions that are conducive to greater Occupancy modeling in 2005 and 2007 separated by distance (more than 6 mi flea densities. The impact of plague documented Gunnison’s prairie dog (10 km)) and impassable geographical epizootics in montane habitat is great occupancy of 17.6 percent and 27.0 features such as rivers and mountains because the small, isolated populations percent, respectively, in the Southern (Lomolino et al. 2003, p. 116; cannot recolonize. Within the South Ute Reservation (part of the La Plata- Pizzimenti and Hoffman 1973, p. 1). Park, Gunnison, and Southeast montane Archuleta population area), and 15.6 Recently, plague has been implicated population areas in Colorado, no prairie percent and 16.3 percent in the in the loss of several large colonies on dog complexes that approach a size Southwest area (CDOW 2007, p. 19). BLM land within the Gunnison considered sustainable exist, and only a The persistence of these populations, population area (CDOW 2007, p. 4). A few small complexes exist within the while undergoing repeated plague large colony southeast of Gunnison, San Luis Valley population area (CDOW outbreaks, is likely due to their Colorado, that was very active in 2005, 2007, pp. 1–17). Without a proximity to other populations within was totally devoid of prairie dogs in metapopulation structure, an overall the prairie portion of the species’ range

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and immigration from those approximately 425 square mi (1,100 main factors: (1) The availability of populations. square km) around 1996. The Arizona other source populations to recolonize In Arizona, from 1987 to 2001, an Game and Fish Department conducted an area; and (2) the frequency of estimated 68 percent reduction in the surveys in this area between 1990 and epizootic outbreaks, which can reduce number of active Gunnison’s prairie dog 1994, and identified 47 active colonies population numbers more quickly than colonies occurred, primarily due to that covered approximately 8,649 ac individual prairie dogs from outbreaks of plague (Underwood 2007, (3,500 ha). In 1996, die-offs were neighboring colonies can recolonize. p. 18; Wagner and Drickamer 2002, p. observed in this area, and the U.S. Populations in the more mesic 15). However, in the area known as the Centers for Disease Control and montane areas of Gunnison’s prairie dog Coconino Plateau, the area occupied by Prevention confirmed plague as the range appear to have been widely and Gunnison’s prairie dogs increased from cause. Although prairie dog numbers severely affected by plague. This may be 2,126 ac (860 ha) in 1992 to 40,942 ac were increasing again in 1998, surveys partly due to climatic conditions such (16,569 ha) in 2007 (Van Pelt 2007, p. in 2001 indicated that only 11 of the 47 as higher levels of spring moisture, 3), suggesting the species can withstand colonies were active. Possibly another, which has been shown to increase flea large plague epizootics through colony undocumented, plague outbreak numbers, and in turn, plague outbreaks. expansion or recolonization from nearby occurred in 1999 or 2000, again Isolation of prairie dog populations does colonies. In addition, the Aubrey Valley reducing the number of individuals not seem to protect them from the Complex (in northwestern Arizona, the (Underwood 2007, p. 19). Despite this spread of plague, because it appears that westernmost part of the species’ range) persistent plague activity, Gunnison’s plague exists with all parts of the range has remained stable since at least 1974, prairie dogs are becoming reestablished at some level, and can be spread by despite the presence of plague, and the in some areas within the boundaries of wider-ranging animals. The case studies size of this complex increased from the Seligman outbreak (Wagner and cited in this section indicate that large approximately 30,000 ac (12,000 ha) in Drickamer 2002, pp. 14–15). This populations have been repeatedly 1997 (Underwood 2007, p. 23), to apparent resiliency is most likely due to affected by plague and have shown no 40,000 ac (16,800 ha) in 2005 (Van Pelt immigration from other colonies in the substantial recovery over long periods of 2005, p. 2), to 47,785 ac (19,338 ha) in prairie portion of the species’ range. time—decades in some cases. This has 2007 (Van Pelt 2007, p. 2). Gunnison’s Plague cycles have been observed in left smaller, more scattered populations prairie dogs at this site had significantly Gunnison’s prairie dogs in Utah, and throughout the montane range portion higher levels of antigens associated with populations have been known to die off and a complete lack of metapopulation disease-causing pathogens such as and then recover (Lupis et al. 2007, p. structure, with the result that areas plague, the same immune response 32). Because plague testing has not been affected by plague are less likely to be expected if the prairie dogs had been conducted on Gunnison’s prairie dogs recolonized by nearby populations. vaccinated against plague (Wagner and in Utah, declines cannot definitively be While little information is currently Van Andel 2007, p. 2). attributed to the disease (Seglund et al. available on prairie dog movement Of 293 colonies surveyed within 2005, p. 52). Plague is anticipated to be within this montane habitat, its Gunnison’s prairie dog range in Arizona an ongoing threat to Gunnison’s prairie geography (populations are located in outside of Tribal lands, 57 (19 percent) dog populations in Utah at both a valleys between mountainous areas) experienced die-offs during the localized, and a widespread, scale probably impedes the ability of prairie summers of 2000 and 2001 (Wagner and (Lupis et al. 2007, p. 32). The Utah dogs to recolonize populations. Within Drickamer 2002, p. 13). Plague was Division of Wildlife Resources recently this geographic area, CDOW found confirmed as the causative agent for 15 conducted point surveys and found that slightly more than 3 percent occupancy of these 57 colonies but is thought to be occupancy was 15.7 percent. Based on of surveyed plots. the likely cause for them all, because it observed occupancy, they estimate that Although documented population is the only disease that causes outbreaks roughly 40,000 ac (16,000 ha) of declines due to plague outbreaks also with high mortality in prairie dogs southeastern Utah were inhabited by occur in the more xeric prairie portions (Barnes 1993, p. 34; Wagner and Gunnison’s prairie dogs in 2007. of Gunnison’s prairie dog range, Drickamer 2002, p. 13). During surveys, Of 65 Gunnison’s prairie dog colonies evidence shows that many of these they also identified the approximate occupied prior to 1984 in west-central populations recover more rapidly from boundaries of two previous plague New Mexico, 32 (49 percent) were still plague epizootics, probably due to the outbreaks (Wagner and Drickamer 2002, occupied in 2005 (Luce 2005, p. 4). The availability of nearby colonizers. This p. 14). active colonies were estimated to cover portion of the range has maintained a An outbreak occurred over 5,997 ac (2,399 ha) (Luce 2005, p. 5). metapopulation structure that provides approximately 1,120 square mi (2,900 The New Mexico Department of Game source populations for plague-affected square km) west of the town of Dilkon, and Fish recently initiated occupancy populations. The largest population in Arizona, on the Navajo Indian modeling surveys similar to those used Arizona, Aubrey Valley in the driest Reservation. This outbreak probably by CDOW and the Utah Division of portion of the range, has been increasing occurred in 1995 or 1996 (Wagner and Wildlife Resources; however, we in recent years and shows indications of Drickamer 2004, p. 14). Previous currently have no data from that effort. exposure to plague without the surveys in the area documented 45 devastating effects observed elsewhere. colonies on 8,649 ac (3,500 ha). Summary of Factor C The CDOW data documents Reexamination of these colonies in 2000 The studies cited above document the approximately 18 percent occupancy and 2001 showed that all but two serious impact that plague has on within prairie habitat in Colorado. colonies were inactive. At most of the Gunnison’s prairie dogs. Although Studies in Utah and west-central New inactive colonies, burrow entrances plague antibody titers have been found Mexico indicate a historic decline in were completely closed, and only in a few individuals, periodic epizootic habitat occupancy of approximately 50 mounds indicated where they formerly plague events generally kill more than percent (Wright 2007, p. 3; Luce 2005, occurred. 99 percent of an affected population. p. 4), and a greater decline in Arizona An outbreak occurred east of the town Whether individual populations recover (Wagner and Drickamer 2002, p. 11). of Seligman, Arizona, across from these epizootics depends on two While this is significant, it is far less

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than the declines seen in the montane such as agricultural lands, Utah, and have no special conservation habitat area; in addition, transportation, and zoning for various status in Colorado or New Mexico. All metapopulation structure continues to types of land use have the potential to four States discuss the Gunnison’s exist, and at least one Gunnison’s influence the Gunnison’s prairie dog or prairie dog in Comprehensive Wildlife prairie dog complex (Aubrey Valley, its habitat; for example, zoning that Conservation Strategies (Seglund et al. Arizona) is exhibiting some resistance to protects open space might retain 2005, p. 55) that confer no regulatory plague epizootics. suitable habitat, and zoning that allows mechanisms, but assert that the species The impacts of plague appear to be a housing development might destroy or is at risk, declining, and deserving of ongoing with moderate population-level fragment habitat. special management consideration. effects when assessed across the entire Colorado State Statute C.R.S. 30–28– In Arizona, all prairie dog species are range of the Gunnison’s prairie dog. 101 exempts parcels of land of 35 ac (14 classified as nongame mammals, and a Within the prairie portion of the range, ha) or more per home from regulation, hunting license is required to shoot plague has reduced the number of so county zoning laws in Colorado only them (Underwood 2007, p. 27). In 2001, populations, and is reducing the size of restrict developments with housing the hunting season for Gunnison’s populations, but has not decimated the densities greater than one house per 35 prairie dogs was changed from year- existing metapopulation structure. ac (14 ha). This State statute allows round to an April 1 to June 15 closure Gunnison’s prairie dog colonies in some parcels to be exempt from county that applies to Federal, State, and prairie habitat exhibit rebound and regulation and may negatively impact private lands (Underwood 2007, p. 28). recovery from plague epizootics in some prairie dogs. In Colorado, the Gunnison’s prairie dog is classified as a small game species, many population areas due to Tribal Laws and Regulations availability of animals from adjacent and take is allowed by rifle, handgun, colonies. So far, plague has resulted in Approximately 49 percent of potential shotgun, handheld bow, crossbow, moderate effects to the species in the Gunnison’s prairie dog habitat occurs on pellet gun, slingshot, falconry, and prairie portion of the range. Tribal lands (Seglund et al. 2005, p. 21). toxicants (CDOW 2007, pp. 41–42). A Within the montane portion of the On the Navajo Nation, Gunnison’s small game license is required, with the range, plague has significantly reduced prairie dog is classified as small game, exception of private landowners and the number and size of populations, and a hunting license is required to their immediate family members or shoot them (Cole 2007, p. 4). In general, resulting in high effects to the species. designees, who may take Gunnison’s access and permission to hunt on Tribal Populations within montane habitat prairie dogs causing damage on their lands are limited for non-Tribal have three distinct disadvantages in lands. Shooting on public lands is not members as a result of various trespass resisting the effects of plague: allowed between March 1 and June 14 (1) A higher frequency of epizootics laws, but access by Tribal members is (no take is permitted in any season on due to the moister montane climate that not limited. We are aware of no seasonal national wildlife refuges) (CDOW 2007, is conducive to higher abundance of shooting closures in effect on Tribal pp. 41–42). During the open season, no fleas that spread plague; land. Work on the Navajo Nation bag or possession limits exist; however, (2) smaller populations that cannot Gunnison’s Prairie Dog Management contestants in shooting events may take recover in numbers from plague Plan, which will incorporate elements no more than five prairie dogs per event epizootics; and of the Arizona, New Mexico, and Utah (CDOW 2007, pp. 41–42). No seasonal (3) isolated populations and no State plans, is expected to begin shooting closures are in effect on private metapopulation structure, due to immediately after finalization of the or Tribal lands. reduced population sizes from past Gunnison’s prairie dog rangewide In New Mexico, Gunnison’s prairie plague epizootics and montane inventory (Cole 2007, p. 5). The Navajo dogs may be taken year-round without geography, and therefore a significantly Nation allows lethal and non-lethal a permit by residents; non-residents are limited ability to recolonize. removal of Gunnison’s prairie dogs for required to obtain a New Mexico After assessing the best available agricultural, human health, and safety hunting license to shoot prairie dogs science on the magnitude and extent of purposes (Cole 2007, pp. 4, 5) within the State (Seglund et al. 2005, the effects of plague, we find that the We are not aware of any other Tribal pp. 31, 32). In Utah, shooting of Gunnison’s impact of plague in the montane portion ordinances that provide for protection prairie dogs is prohibited on public of the Gunnison’s prairie dog range is or conservation of the Gunnison prairie lands from April 1 to June 15, but they significant. However, plague does not dog or its habitat. We recognize that may be taken on private lands year- rise to a level of being a significant Tribal ordinances that address issues round; no license is required for threat to the Gunnison’s prairie dog such as agricultural lands, shooting Gunnison’s prairie dogs, and throughout its range. transportation, and zoning for various types of land uses have the potential to no bag limit exists (Lupis et al. 2007, pp. D. Inadequacy of Existing Regulatory influence the Gunnison’s prairie dog or 18–19). Mechanisms its habitat; for example, zoning that Access and permission to hunt on private and Tribal lands are limited as Local Laws and Regulations protects open space might retain suitable habitat, and zoning that allows a result of various trespass laws. All Approximately 22 percent of potential a housing development might destroy or States that provide habitat for Gunnison’s prairie dog habitat occurs on fragment habitat. Gunnison’s prairie dogs allow their private lands, and another 30 percent removal for agricultural, human health, occurs on Tribal lands or lands managed State Laws and Regulations and safety purposes (Seglund et al. by the Bureau of Indian Affairs (Seglund Approximately 12 percent of 2005, p. 46). et al. 2005, p. 21). We are not aware of Gunnison’s prairie dog potential habitat The States within the range of the any city, or county ordinances that occurs on State and Federal lands Gunnison’s prairie dog developed a provide for protection or conservation of (Seglund et al. 2005, pp. 82). Rangewide Conservation Strategy that the Gunnison prairie dog or its habitat. Gunnison’s prairie dogs are considered provides guidance regarding specific We recognize that city, county, and a Species of Greatest Conservation Need activities to include in individual State Tribal ordinances that address issues in Arizona, a State Sensitive Species in plans for prairie dog conservation and

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management (Seglund et al. 2005, p. dogs, when conducting activities in on NatureServe rankings (USFS 2004, 55). All of the States with Gunnison’s their habitat. pp. 60, 64). Management of Federal prairie dog habitat are in the process of The Gunnison’s prairie dog is activities on National Forest System developing State Conservation Plans. designated by BLM as a sensitive lands is guided principally by the The four plans are in different phases of species in Utah only; therefore, they are National Forest Management Act development but are scheduled for not required to provide special (NFMA) (16 U.S.C. 1600–1614, August completion by March 2008. The four protections and mitigation during 17, 1974, as amended). The NFMA States have agreed on a monitoring project and activity planning in specifies that all national forests and strategy to determine population trends Arizona, Colorado, or New Mexico. grasslands must have a Land and of Gunnison’s prairie dog across their BLM’s Resource Management Plans Resource Management Plan (LRMP) (16 range (Van Pelt 2007, p. 2). (RMPs) are the basis for all of its actions U.S.C. 1600) to guide and set standards Within Colorado, in the montane and authorizations involving BLM- for natural resource management portion of the species’ range, CDOW has administered lands and resources. They activities. The NFMA requires the USFS designated individual population areas establish allowable resource uses; to incorporate standards and guidelines to identify where Gunnison’s prairie resource condition, goals and objectives into LRMPs (16 U.S.C. 1600). This has dogs exist and where management to be attained; program constraints and historically been done through a NEPA activities should be focused. This general management practices needed to process. Provisions to manage plant and portion of the species’ range is attain the goals and objectives; general animal communities for diversity, based comprised of the Gunnison, San Luis implementation sequences; and on the suitability and capability of a Valley, South Park, and Southeast intervals and standards for monitoring specific land area, are developed in population areas. and evaluating the plan to determine its order to meet overall multiple-use The Gunnison population area is effectiveness and the need for objectives. approximately 68 percent Federal, and 2 amendment or revision (43 CFR 1601.0– The 1982 NFMA implementing percent State, 30 percent private 5(k)). regulation for land and resource ownership (CDOW 2007, p. 2). The San RMPs provide a framework and management planning (1982 rule, 36 Luis Valley population area is programmatic guidance for site-specific CFR 219), under which all existing approximately 40 percent Federal, 6 activity plans. Site-specific plans forest plans were prepared, requires the percent State, and 54 percent private address livestock grazing, oil and gas USFS to manage habitat to maintain ownership (CDOW 2007, p. 2). The field development, travel management, viable populations of existing native South Park and Southeast population wildlife habitat management, and other vertebrate species on National Forest areas are 34 percent Federal, 7 percent activities. Activity plan decisions System lands (1982 rule, 36 CFR State, and 59 percent private ownership. normally require National 219.19). A new USFS planning The large percentage of private lands, Environmental Policy Act (NEPA) (42 regulation was promulgated on January where minimal regulatory mechanisms U.S.C. 4321 et seq.) analysis. 5, 2005 (70 FR 1023), and supersedes exist, appears to compound the effects The BLM has regulatory authority for the 1982 rule. Plans developed under of shooting and poisoning in this oil and gas leasing and operating, as the new regulation are to be more montane portion of the species’ range provided at 43 CFR 3100 et seq. BLM strategic and less prescriptive in nature that is already at lower occupancy than usually incorporates stipulations as a than those developed under the 1982 the prairie portion of the species, condition of issuing a lease. The BLM’s planning rule. For example, previous especially in conjunction with plague planning handbook has program- plans might have included a buffer for for which there are no regulatory or specific guidance for fluid minerals activities near the nest sites of birds protective mechanisms. (which include oil and gas) that sensitive to disturbance. Under the new specifies that RMP decision-makers will regulation, a desired condition United States Federal Laws and consider restrictions on areas subject to description and guidelines will be Regulations leasing, including closures, and lease provided, rather than a set of Federal agencies are responsible for stipulations (BLM 2000, Appendix C, p. prescriptive standards that apply to managing approximately 17 percent of 6). The handbook also specifies that all projects. Planning, and decisions for Gunnison’s prairie dog habitat. The stipulations must have waiver, projects and activities, will address site- primary Federal agency managing exception, or modification criteria specific conditions and identify Gunnison’s prairie dog habitat is BLM documented in the plan, and indicates appropriate conservation measures to (12 percent); the USFS (4.3 percent), that the least restrictive constraint to take for each project or activity. National Park Service (0.5 percent), meet the resource protection objective However, this planning regulation was Department of Defense (0.4 percent), should be used (BLM 2000, Appendix C, struck down by the U.S. District Court and the Service (0.1 percent) also p. 6). The BLM has regulatory authority for the Northern District of California on contribute to management of the to condition drilling permits to include March 30, 2007, and is not currently in species. prairie dog conservation stipulations use by the USFS. We are uncertain (BLM 2004, pp. 3–60). Some oil and gas which direction the USFS is Bureau of Land Management leases have a 0.12-mi (0.19-km) implementing for the Gunnison’s prairie The Federal Land Policy and stipulation, which allows movement of dog, or whether Gunnison’s prairie dog Management Act of 1976 (FLPMA) (43 the drilling area by that distance (BLM habitat objectives and conservation U.S.C. 1701 et seq.) is the primary 2004). We do not have data to evaluate measures have been incorporated into Federal law governing most land uses the effectiveness of BLM’s program on grazing allotment plans or LRMPs. on BLM lands. Section 102(a)(8) of prairie dog conservation. FLPMA specifically recognizes wildlife Summary of Factor D and fish resources as being among the U.S. Forest Service On a basis on a review of the available uses for which these lands are to be The Gunnison prairie dog is a USFS existing information, it does not appear managed. BLM must consider the needs Sensitive Species in New Mexico and that the inadequacy of existing of wildlife, including general Colorado, where it is considered to be regulatory mechanisms is a significant considerations of Gunnison’s prairie imperiled (USFS 2007, line 135) based threat to the Gunnison’s prairie dog.

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However, the percentage of private shift in range for many species (IPCC characteristics are relevant to the lands within the montane portion of the 2007, pp. 2–5); the higher elevation species’ ability to sustain stable species’ range results in a paucity of montane habitat could be essential to populations in the presence of ongoing, regulatory mechanisms that potentially future conservation of the Gunnison’s low intensity threats such as predation, result in increased shooting and prairie dog. We have no knowledge of poisoning, and shooting. However, we poisoning, which exacerbate the effects more detailed climate change find that the ability of populations to of plague in that portion of its range. At information specifically for this recover from plague epizootics is more this time, no regulatory mechanisms montane portion of the Gunnison’s relevant to the foreseeable future of the exist to mitigate the effects of plague. prairie dog range. species. As described under Factor C above, E. Other Natural or Manmade Factors Summary of Factor E prairie dog populations can experience Poisoning of Gunnison’s prairie dogs Although poisoning contributed mortality rates of greater than 99 percent has historically been documented historically to large declines in during plague epizootics and can be throughout the species’ range, but no occupied area of Gunnison’s prairie eradicated within one season due to evidence indicates that poisoning dogs, there is no information available plague. Recovery rates, which are key to currently occurs on a broad scale. The to indicate that poisoning occurs at population survival, depend on several WAFWA Gunnison’s Prairie Dog more than a localized scale today. factors, including susceptibility to Conservation Assessment summarizes Poisoning could have a negative effect plague, frequency of plague outbreaks, poisoning campaigns in the four States on small, isolated populations, habitat quality, and distance to other (Seglund et al. 2005, pp. 56–57). From particularly in conjunction with disease colonies available for recolonization. 1914 to 1964, 2,310,203 ac (934,906 ha) and shooting; therefore, poisoning in the Current data frame our analysis and of Gunnison’s prairie dog habitat were montane area may be more likely to help us understand what factors can poisoned in Arizona; 23,178,959 ac contribute to the decline of the species reasonably be anticipated to (9,380,192 ha) of habitat were poisoned by further fragmenting the small meaningfully affect the species’ future in Colorado; 20,501,301 ac (8,296,582 populations and curtailing conservation status. We have ha) of habitat were poisoned in New recolonization. No information documented that Gunnison’s prairie dog Mexico; and 2,715,930 ac (1,099,098 ha) currently indicates that drought occupancy varies significantly across its of habitat were poisoned in Utah. On negatively affects or is likely to affect range, that susceptibility to extirpation public lands, poisoning efforts have led the Gunnison’s prairie dog throughout by plague is greater in the montane to a reduction in occupied habitat, its range, or that climate change will portion of the species’ range, and that extirpation from local areas, affect the species within the foreseeable metapopulation structure does not exist fragmentation, and isolation of colonies. future. While poisoning of Gunnison’s and recolonization is nearly nonexistent Poisoning in all States became less prairie dogs and the effects of climate in the montane portion of the range. common after Federal regulation of change in the montane portion of the While we have data indicating that pesticides was enacted. State and range are issues important to monitor, Gunnison’s prairie dog numbers and Federal agencies are rarely involved in we conclude that no other natural or populations have decreased, we control efforts unless human health and manmade factors are a significant threat currently have no data on which to base safety are at risk (Seglund et al. 2005, p. to this species, at this time, throughout rates of decline in any portion of that 57). Individual landowners may still all or a significant portion of its range. range, which hinders our ability to control prairie dogs on their private Foreseeable Future determine the foreseeable future for the property. species. We must estimate the No studies indicate that drought has When determining whether a species foreseeable future of the Gunnison’s a negative rangewide effect on is in danger of extinction throughout all prairie dog based on current occupancy Gunnison’s prairie dogs. Impacts to the or a significant portion of its range, or and our knowledge of the magnitude of Gunnison’s prairie dog under predicted is likely to become in danger of the threat of plague. Plague has been future climate change are unclear. A extinction in the foreseeable future, we shown to nearly extirpate entire trend of warming in the mountains of must define that foreseeable future for population areas over a span of 3 to 10 western North America is expected to the species. We do this on a case-by- years (such as South Park and San Luis decrease snowpack, hasten spring case basis, taking into account a variety Valley in Colorado and Moreno Valley runoff, and reduce summer flows (IPCC of species-specific factors such as in New Mexico) (Fitzgerald 1993; 2007, p. 10). Increased summer heat lifespan, genetics, breeding behavior, CDOW 2007; Cully et al. 1997) and can may increase the frequency and demography, threat-projection extirpate small populations in 1 to 2 intensity of wildfires (IPCC 2007, p. 14). timeframes, and environmental years (Fitzgerald 1970; Lechleitner et al. Given the different climate variables variability. For the purposes of this 1962; Turner 2001). between the montane and prairie finding, we define foreseeable future Plague has been present within the geographic areas, populations in prairie based on a threat-projection timeframe, range of the Gunnison’s prairie dog for habitat may show evidence of effects because plague is likely to be the single 70 years (Eskey and Haas 1940, p. 6) and from climate change earlier than those greatest factor contributing to the will likely continue to exist within the in montane habitat. While it appears species’ future conservation status, as range in perpetuity, because it remains reasonable to assume that Gunnison’s explained below. widespread and strongly entrenched prairie dogs may be affected, we lack Life history characteristics are of among wild rodent populations in the sufficient certainty on knowing how secondary relevance to Gunnison’s western United States (Barnes 1993, p. climate change will affect the species, or prairie dog foreseeable future. 31). Current information suggests that the potential changes to the level of Gunnison’s prairie dogs breed once per Gunnison’s prairie dog has not threat posed by plague. The most recent year and produce an average litter size developed sufficient immunity to literature on climate change includes of 3.77. They can become sexually reduce the effects of plague; we predictions of hydrologic changes, mature at 1 year of age, but survivorship anticipate it will not develop such higher temperatures, and expansion of is less than 60 percent during their first immunity within the foreseeable future. drought areas, resulting in an upward year (Seglund et al. 2005, p. 15). These Few records document Gunnison’s

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prairie dog individuals with plague populations at a rate we can’t anticipate. its loss would result in a decrease in the antibody titers (Cully et al. 1997, p. 717; However, we find that an estimate of 35 ability of the species to persist. Cully and Williams 2001, p. 898). years as the foreseeable future of the The first step in determining whether Individual prairie dogs in the Aubrey Gunnison’s prairie dog is reasonable, a species is threatened or endangered in Valley of Arizona had antigens that because it focuses this status review on a significant portion of its range is to provided an immune response similar to the known effects from plague, and our identify any portions of the range of the that expected if they had been best assessment that prairie dogs will species that warrant further vaccinated; however, the mechanism is not soon develop immunity to the consideration. The range of a species unknown—that is, we do not know disease. We know of no other species can theoretically be divided into whether the response is a result of that have developed an immunity to portions in an infinite number of ways. exposure to plague or is innate (Wagner plague. To identify portions that warrant further and Van Andel 2007, p. 2), and we do Based on currently available data on consideration, we determine whether not know if the number of individual the continued presence of plague and its there is substantial information prairie dogs that have antigens are effects, we have determined that the indicating that (1) the portions may be enough to protect whole colonies. We species, rangewide, is not likely to significant, and (2) the species may be have no documented records of become endangered within the in danger of extinction there or likely to resistance being passed to offspring. foreseeable future, which we have become so within the foreseeable future. More studies and testing need to be determined to be the year 2043. In practice, a key part of this analysis is conducted on a plague vaccine that has However, while some populations in the whether the threats are geographically had limited success in laboratory montane portion of the range have so far concentrated in some way. If the threats experiments on black-tailed prairie persisted, their long-term viability is to the species are essentially uniform dogs; individual black-tailed prairie compromised by the lack of throughout its range, no portion is likely dogs have developed antigens to plague metapopulation structure. In the prairie to warrant further consideration. in response to the vaccine. The vaccine portion of the range, the many more Moreover, if any concentration of has not yet been tested on Gunnison’s populations and the metapopulation threats applies only to portions of the prairie dogs, and even if we had an structure that enable recolonization after range that are unimportant to the effective vaccine, we currently have no plague epizootics, continue to persist, conservation of the species, such method of applying it to prairie dog and in our judgment, will continue to portions will not warrant further populations. persist into the foreseeable future. consideration. If we identify any portions that We do not have sufficient Significant Portion of the Range warrant further consideration, we then information, such as trend data, on the Analysis trajectory of plague to develop a precise determine whether the species is definition of foreseeable future. In the As required by the Act, we considered threatened or endangered in any 70 years plague has been present in the five potential threat factors to assess significant portion. If we determine that Gunnison’s prairie dog habitat: (1) whether the Gunnison’s prairie dog is a portion of the range is not significant, Populations in the montane portion of threatened or endangered throughout all we do not determine whether the the range have become isolated and no or a significant portion of its range. species is threatened or endangered longer comprise a metapopulation When considering the listing status of there. structure; and (2) populations in the the species, the first step in the analysis The terms ‘‘resiliency,’’ prairie portion of the range have is to determine whether the species is in ‘‘redundancy,’’ and ‘‘representation’’ are maintained a metapopulation structure, danger of extinction throughout all of its intended to be indicators of the but occupancy has been reduced by 50 range. If this is the case, then we list the conservation value of portions of the percent or more. The trajectory of species in its entirety. For instance, if range. Resiliency of a species allows it plague effects is difficult to assess, the threats to a species are directly to recover from periodic disturbances. A because, as populations are reduced in acting on only a portion of its range, but species will likely be more resilient if size or extirpated, the effects of plague they are at such a large scale that they large populations exist in high-quality multiply at a faster rate. Using the best place the entire species in danger of habitat that is distributed throughout its available information, we find that, if extinction, we would list the entire range in a way that captures the occupied habitat within the prairie species. environmental variability available. A portion of the range was reduced by at We next consider whether any portion of the range of a species may least 50 percent in 70 years, the species significant portion of the Gunnison’s make a meaningful contribution to the could be facing significant effects within prairie dog range meets the definition of resiliency of the species if the area is a much shorter timeframe than another endangered or is likely to become relatively large and contains particularly 70 years. Our best estimate at this time endangered in the foreseeable future high-quality habitat, or if its location or is that within half that time, another 35 (threatened). On March 16, 2007, a characteristics make it less susceptible years or fewer, plague may eliminate the formal opinion was issued by the to certain threats than other portions of metapopulation structure remaining Solicitor of the Department of the the range. When evaluating whether or within the prairie portion of the range. Interior, ‘‘The Meaning of ‘In Danger of how a portion of the range contributes Therefore, we find that the foreseeable Extinction Throughout All or a to resiliency of the species, we evaluate future of the Gunnison’s prairie dog is Significant Portion of Its Range’’’ (DOI the historical value of the portion and 35 years. It is possible that Gunnison’s 2007). A portion of a species’ range is how frequently the portion is used by prairie dogs may develop immunity to significant if it is part of the current the species, if possible. The range plague, or to rebound in numbers that range of the species and is important to portion may contribute to resiliency for enable it to withstand cyclic outbreaks the conservation of the species because other reasons; for instance, it may of the disease, making the trajectory of it contributes meaningfully to the contain an important concentration of plague longer than 35 years. It is also representation, resiliency, or certain types of habitat that are possible that plague will continue on a redundancy of the species. The necessary for the species to carry out its more rapid trajectory that extirpates contribution must be at a level such that life-history functions, such as breeding,

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feeding, migration, dispersal, or We assessed whether we should redundancy of the species by increasing wintering. consider smaller geographic units, such risk of extirpation by a natural or Redundancy of populations may be as population areas. Given the best anthropogenic event, reducing adaptive needed to provide a margin of safety for scientific and commercial information characteristics to geographical or the species to withstand catastrophic available, we found that individual climatic conditions, and reducing events. This concept does not mean that population areas did not meaningfully remaining genetic variation. any portion that provides redundancy is contribute to the representation, The most recent literature on climate per se a significant portion of the range resiliency, or redundancy of the species. change includes predictions of of a species. The idea is to conserve The scale at which we define the hydrologic changes, higher enough areas of the range so that range of a particular species, that is, at temperatures, and expansion of drought random perturbations in the system a relatively coarse or fine scale, depends areas, resulting in an upward shift in only act on a few populations. on the life history of the species, the range for many species (IPCC 2007, pp. Therefore, we examine each area based data available, and the purpose for 2–5); the higher elevation montane on whether that area provides an defining the range. habitat could be essential to future increment of redundancy that is As with other determinations under conservation of the Gunnison’s prairie important to the conservation of the the Act, we define the current range on dog. These factors lead us to the species. the basis of the best available data. The conclusion that loss of the Gunnison’s Adequate representation ensures that purpose of defining range (and hence prairie dog within the montane portion the species’ adaptive capabilities are the significant portion of the range) is to of its range would reduce the ability of conserved. Specifically, we evaluate a set the boundaries of the protections of the species to persist. the Act. Therefore, defining the range portion to see how it contributes Status of Montane Range to the genetic diversity of the species. boundaries too narrowly may lead to the If we identify any range portions as The loss of genetically based diversity failure to protect some Gunnison’s significant, we then determine whether may substantially reduce the ability of prairie dogs. We have determined that it the species is threatened or endangered the species to respond and adapt to is appropriate to use a relatively coarse in this significant portion of its range. future environmental changes. A scale to capture all of the areas where peripheral population may contribute the best available data suggests the Summary of Factors Affecting the meaningfully to representation if there Gunnison’s prairie dog is likely to Species Within the Montane Portion of is evidence that it provides genetic occur. the Range diversity due to its location on the The map boundaries in Figure 1 above show the Gunnison’s prairie dog range. We evaluated whether threats to the margin of the species’ habitat Gunnison’s prairie dog may affect its requirements. Discovery of currently existing Gunnison’s prairie dog populations survival within the montane portion of Based on the discussion above, we outside these boundaries is unlikely. its range, separately from the entire identified the montane portion of the The map boundaries show the range. Our evaluation of threats within current range of the Gunnison’s prairie significant montane portion, which is the montane portion of the range (based dog as warranting further consideration inclusive of all areas likely to support on information provided in the petition, to determine if it is a significant portion Gunnison’s prairie dog populations in available in our files, and available in of the range that is threatened or the montane habitat. published and unpublished studies and endangered. This portion of the range in reports) is presented below. central and south-central Colorado, and Significance of the Montane Range A. The Present or Threatened north-central New Mexico, constitutes When Gunnison’s prairie dog colonies approximately 40 percent of the current Destruction, Modification, or are well distributed across their current Curtailment of Its Habitat or Range overall range. range, which currently includes an Conservation principles indicate that Defining Portions of the Range estimated 5 percent of the historical range, they are less susceptible to smaller, more isolated populations are In defining the portion of the current extinction than when colonies are more vulnerable to extirpation (Barnes range that we considered further, we confined to only a portion of their range. 1993, p. 34; Cully 1993, p. 43; Fitzgerald relied on range maps produced by The montane habitat within Gunnison’s 1970, p. 78; Gilpin and Soule 1986, pp. mammalogists and geneticists that prairie dog range contains populations 30–31; Miller et al. 1994, p. 151; delineate the boundaries of the montane significant to the overall viability of the Mulhern and Knowles 1995, p. 21; and prairie portions of the Gunnison’s species, because they represent: Wilcox and Murphy 1985, p. 883; prairie dog’s range. We believe the • Approximately 40 percent of the Wuerthner 1997, p. 464). Lomolino et threats to the species are significantly species’ current habitat; al. (2003, p. 116) found that persistence different in the two range portions. The • Populations in unique, higher of Gunnison’s prairie dog colonies geography of each area differs elevation habitat, and adaptations increased significantly with larger significantly, affecting the ability of the relevant to this habitat; colony size and decreased isolation. The prairie dog to respond to threats. • Genetic material substantially populations within the montane portion Unpublished genetic analysis shows unique within the range of the of the range are smaller and more differences in Gunnison’s prairie dogs Gunnison’s prairie dog (Hafner 2004, p. isolated. However, we found no studies between the two areas (Hafner et al. 6; Hafner et al. 2005, p. 2). or data that specifically assess the 2005, p. 2). This analysis is not yet The relatively large proportion of the magnitude of the threats related to complete enough to definitively indicate entire range represented by the montane agriculture land conversions, that two separate subspecies exist; habitat adds a significant number of urbanization, grazing, roads, and oil and however, along with subspecies Gunnison’s prairie dog populations gas leasing, and resulting fragmentation delineation, the data also point to widely distributed throughout distinct within the montane portion of possible differences in Gunnison’s geographic areas. Losses of populations Gunnison’s prairie dog habitat. prairie dog adaptations due to physical in montane habitat would affect the After assessing the best available geography. representation, resiliency, and science on the magnitude and extent of

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the effects of agricultural land Harrell 2003, pp. 5–7). A complete die- comprise most of the Gunnison’s prairie conversion, urbanization, grazing, roads, off of a colony due to plague in Chubbs dog montane habitat in Colorado. oil and gas development, and Park, Chaffee County, Colorado, From 1984 through 1987, a plague fragmentation of habitat, we find that occurred in 1959 (Lechleitner et al. event reduced the population of the destruction, modification, and 1962, p. 185). In August 1958, the Gunnison’s prairie dogs in the Moreno curtailment of Gunnison’s prairie dog’s population was stable and healthy, but Valley of New Mexico from more than habitat or range are not significant in 1959 an epizootic spread 2 mi (3 km) 100,000 individuals to between 250 and threats within the montane portion of within 3 months; prairie dogs continued 500, a decline of greater than 99 percent the range. Agriculture, urbanization, to be absent from the area in 1960 and (Cully et al. 1997, pp. 708–711). roads, and oil and gas development each 1961, and we have no recent Although the remaining population currently affect a small percentage of information on the existence of prairie rebounded (increased in size to a certain Gunnison’s prairie dog habitat. Effects dogs in that location. extent) following the epizootic, another of livestock grazing, while widespread, Approximately 1,000 to 1,500 plague event swept through the area in have not resulted in measurable Gunnison’s prairie dogs were killed by 1988, and the population in July 1996 population declines. an outbreak of plague in a 148–ac (60– was still only a small fraction of what ha) colony in Curecanti National it had been in 1984 (Cully et al. 1997, B. Overutilization for Commercial, Recreation Area near Gunnison, p. 717). Recreational, Scientific, or Educational Colorado, in 1981 (Rayor 1985, p. 194). Occupancy modeling performed for Purposes A few animals survived the disease and Colorado in 2005 indicated a lower We have determined that shooting Gunnison’s prairie dogs were again proportion of occupancy in the montane continues to be a threat to the abundant in the area in 1986 (Cully portion of the species’ range within Gunnison’s prairie dog within the 1989, p. 49). In 2002, 252 ac (102 ha) of Colorado (3.2 percent) than in the montane portion of its range and habitat in the Recreation Area were prairie portion within Colorado (16.0 contributes to the decline of the species occupied by Gunnison’s prairie dog percent) (Andelt et al. 2006, p. 17; when combined with the effects of colonies (Capodice and Harrell 2003, p. CDOW 2007, p. 19). When the study disease (see Factor C below). However, 23), but the current estimate is 12 ac (4.8 was repeated over the same plots in this threat is being monitored and ha) (Childers 2007, p. 2). Colonies 2007, occupancy was again found to be managed by the States of Colorado and within the Recreation Area experienced lower (3.6 percent) in the montane range New Mexico, and modeling results six plague epidemics between 1971 and portion in Colorado than in the suggest seasonal shooting closures 2007. Of the 9 historic Gunnison’s southwestern portion (18.3 percent) implemented in Colorado will likely prairie dog colonies, 3 are currently (CDOW 2007, p. 19). The only recent reduce population-level losses. active, and 2 act as source populations threat responsible for whole population Therefore, we have determined that for the main prairie dog concentration declines and extirpations, as overutilization for commercial, area (Childers 2007, p. 1). If the source documented in the studies cited in this recreational, scientific, or educational colonies die off due to plague, section, is plague. purposes is not a significant threat to repopulation may not be possible The frequency of plague epizootics the Gunnison’s prairie dog within the because any other Gunnison’s prairie appears to be high in montane habitat montane portion of its range. dog populations remaining will be due to moister environmental conditions that are conducive to greater C. Disease or Predation separated by distance (more than 6 mi (10 km)) and impassable geographical flea densities. The impact of plague Several well-studied colonies within features such as rivers and mountains epizootics in montane habitat is great the montane portion of the Gunnison’s (Lomolino et al. 2003, p. 116). because the small, isolated populations prairie dog range have been documented Recently, plague has been implicated cannot recolonize. Within the South as being extirpated, or nearly so, due to in the loss of several large colonies on Park, Gunnison, and Southeast montane plague. The South Park, Colorado, BLM land within the Gunnison, population areas in Colorado, no prairie population area included estimated Colorado, population area (CDOW 2007, dog complexes of appreciable size exist, occupied habitat of 915,000 ac (371,000 p. 4). A large colony southeast of and only a few small complexes exist ha) in 1945; 74,000 ac (30,000 ha) in Gunnison that was very active in 2005 within the San Luis Valley population 1948; and 42 ac (17 ha) in 2002 (CDOW was totally devoid of prairie dogs in area (CDOW 2007, pp. 1–17). Without a 2007). This decline was largely due to 2006 and 2007. Four other large metapopulation structure, an overall plague and affected a substantial portion colonies in the same vicinity were decline in persistence takes place of the species’ extant occupied habitat active in 2006, but by 2007, no prairie (Lomolino and Smith 2001, p. 942). in Colorado (at least 15 percent). Plague dog activity was observed. Plague is the The landscape status in the montane resulted in the complete loss, over a 2- suspected cause of these extirpations portion of Gunnison’s prairie dog range year period, of a colony within the because of the complete elimination of is characterized by fewer, smaller South Park population area (Fitzgerald the prairie dogs with no sign of colonies that are isolated, and few to no 1970, pp. 68–69). A plague event in poisoning (CDOW 2007, p. 4). complexes or metapopulation structure. Saguache County, Colorado, that Fitzgerald (1993, p. 52) expressed These factors make the prairie dogs in progressed across seven colonies in 2 concern about the status of the this habitat highly susceptible to plague- years left only scattered individuals Gunnison’s prairie dog in Colorado, related declines, and we have no surviving in two colonies (Lechleitner et indicating that plague had eliminated evidence of recovery from plague in the al. 1968, p. 734). In Gunnison, many populations, including almost all montane habitat area. Saguache, and Montrose Counties, of the populations in South Park. He The studies cited above document the Colorado, plague also was responsible also suggested that populations serious impact that plague has on for a decline from 15,569 ac (6,228 ha) appeared to be in poor condition in the Gunnison’s prairie dogs within the of occupied habitat in 1980, to 770 ac San Luis Valley and were extirpated montane portion of the range. Although (308 ha) in 2002 (note that Montrose from the extreme upper Arkansas River plague antibody titers have been found County is in the Southwest population Valley, as well as Jefferson, Douglas, in a few individuals, periodic epizootic area in prairie habitat) (Capodice and and Lake Counties. These areas plague events generally kill more than

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99 percent of an affected population. D. Inadequacy of Existing Regulatory species in danger of extinction Whether individual populations recover Mechanisms (endangered), or makes it likely to from these epizootics depends on two On the basis on a review of the become endangered within the main factors: (1) The availability of available existing information, it does foreseeable future (threatened). other source populations to recolonize not appear that the inadequacy of However, we determined that the Gunnison’s prairie dog is warranted for an area; and (2) the frequency of existing regulatory mechanisms is a listing within the montane portion of its epizootic outbreaks, which can reduce significant threat to the Gunnison’s range (approximately 40 percent of the population numbers more quickly than prairie dog. However, the percentage of species total range). individual prairie dogs from private lands within the montane neighboring colonies can recolonize. The determination of a finding of portion of the species’ range results in threatened or endangered involves Populations in the more mesic a paucity of regulatory mechanisms that weighing the magnitude and immediacy montane areas of Gunnison’s prairie dog potentially result in increased shooting of the threats. The cumulative range appear to have been widely and and poisoning, which exacerbate the magnitude of threats within the severely affected by plague. This may be effects of plague in that portion of its montane portion of the range is high. partly due to climatic conditions, such range. At this time, no regulatory Immediacy of threats varies as higher levels of spring moisture, mechanisms exist to mitigate the effects geographically across the montane which has been shown to increase flea of plague. range, but is high in areas of the numbers, and in turn, plague outbreaks. E. Other Natural or Manmade Factors montane habitat where populations Isolation of prairie dog populations does have already been extirpated, primarily Poisoning could have a negative effect not seem to protect them from the the South Park and Southeast on small, isolated populations, spread of plague, because it appears that population areas. particularly in conjunction with disease plague exists with all parts of the range Within the prairie portion of the and shooting; therefore, poisoning in the Gunnison’s prairie dog’s range, colonies at some level and can be spread by montane area may be more likely to wider-ranging animals. The case studies are subject to the same threats, but at a contribute to the decline of the species different magnitude. Plague has the cited in this section indicate that large by further fragmenting the small populations have been repeatedly same potential to reduce population size populations and curtailing significantly there as in montane affected by plague and have shown no recolonization. However, while substantial recovery over long periods of habitat, but due to more open poisoning bears monitoring, at this time, geography, an existing metapopulation time—decades in some cases. This has we conclude that it is not significantly left smaller, more scattered populations structure, larger population sizes, and affecting the populations within this proximity of other colonies, throughout the montane range portion, portion of the range. No information recolonization has been observed. The with the result that areas affected by currently indicates that drought ability of populations to recolonize plague are less likely to be recolonized negatively affects, or is likely to affect, relatively quickly enables them to by nearby populations. While little the Gunnison’s prairie dog within the recover more fully between plague information is currently available on montane portion of its range, or that enzootics. Ability to recolonize in prairie dog movement within this climate change will affect the species prairie habitat also enables Gunnison’s montane habitat, its geography within the foreseeable future; however, prairie dog populations to recover from (populations are located in valleys various scenarios are plausible. We poisoning and shooting, which act to between mountainous areas) probably conclude that no other natural or exacerbate the more significant threat impedes the ability of prairie dogs to manmade factors are a significant threat from plague. The species’ status in this recolonize populations. Within this to this species, at this time, throughout portion of the range is characterized by geographic area, CDOW found slightly the montane portion of its range. a metapopulation structure, and larger more than 3 percent occupancy of Finding colonies and complexes that are better surveyed plots (CDOW 2007, p.19). able to recover from plague epidemics, Populations within montane habitat The information summarized in this to be recolonized after plague have three distinct disadvantages in status review includes substantial epizootics, and even to colonize new resisting the effects of plague: information that was not available at the areas. time of the 90-day petition finding (71 We determined that the Gunnison’s (1) A higher frequency of epizootics FR 6241, February 7, 2006) and other prairie dog is warranted for listing due to the moister montane climate that information we received during the within the montane portion of its range is conducive to higher abundance of public comment period following the (approximately 40 percent of the species fleas that spread plague; publication of the 90-day finding. This total range). We find that threats, (2) smaller populations that cannot 12-month finding reflects and primarily plague, exist in the montane recover in numbers from plague incorporates information we received portion of their range at a magnitude epizootics; and during the public comment period or that make the species likely to become obtained through consultation, literature threatened or endangered within the (3) isolated populations and no research, and field visits, and responds foreseeable future, which we have metapopulation structure, due to to significant issues identified. We determined to be the year 2043. We reduced population sizes from past determined that the Gunnison’s prairie determined that Gunnison’s prairie dog plague epizootics and montane dog does not meet the definition of populations within the prairie portion geography, and therefore a significantly threatened or endangered throughout its of the range continue to be viable due limited ability to recolonize. entire range, because, within to the functioning metapopulation After assessing the best available approximately 60 percent of its range structure and the apparent resistance to science on the magnitude and extent of (the prairie habitat in the southwestern plague epizootics within the Aubrey the effects of plague, we find that plague portion of its range), the threats Valley, Arizona, complex. Therefore, we is significantly impacting the species in (primarily plague) are not of a find that the Gunnison’s prairie dog the montane portion of its range. magnitude that currently puts the does not warrant listing throughout its

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entire range, but that populations within geography, and therefore a significantly (B) Loss of Gunnison’s prairie dogs in the montane portion of its range are limited ability to recolonize. the montane portion would affect: significant to the continued existence of Some lands within the montane range (i) resiliency of the species, because the species and warrants listing in that supporting the Gunnison’s prairie dog the montane portion represents portion only (see discussion under are controlled by Federal or State approximately 40 percent of the species Significant Portion of the Range agencies, or have been set aside as open range, and the small, isolated Analysis). However, listing the montane space by local governments. However, a populations are not likely to rebound Gunnison’s prairie dog is warranted but greater portion of the montane range is after decimation from plague; precluded at this time by pending private land with fewer regulatory (ii) redundancy of the species, proposals for other species with higher mechanisms in place for conserving because random perturbations are not listing priorities based on taxonomic prairie dogs. likely to act equally on both the uniqueness (the only species described We found that poisoning and shooting montane and prairie portions; and for the genus), or other species that are are not significant threats rangewide. (iii) representation of the species, not currently listed (see discussion While they can have greater impacts on because the montane population is under Preclusion and Expeditious small populations by compounding the genetically distinct from the prairie Progress). effects from the primary threat of plague population and the species’ remaining If future genetic analyses or and further decreasing colony size and genetic diversity would be reduced. taxonomic studies indicate conclusively fragmenting and isolating colonies, at (C) The species is warranted for that two subspecies of Gunnison’s this time poisoning and shooting do not listing in this portion of the range prairie dogs exist, this would affect our appear to be occurring at a level that because: proposed listing. Instead of defining the raises concern above that related to (i) Occupancy data (3 percent) is montane habitat as a significant portion plague. Cumulative threats do, however, significantly lower in the montane range of the range, we would propose listing impede recovery of some populations portion. the subspecies that exists in that habitat. and imperil others. Where recovery does (ii) The montane portion of the range Sylvatic plague is the only significant not occur, Gunnison’s prairie dog no longer has a metapopulation factor affecting the future conservation populations are likely to remain small, structure, and populations reduced by status of the species. Within the fragmented, and susceptible to plague have not rebounded; montane portion of the species’ range, extirpation. repopulation from nearby populations the threat of plague has greater The following summarizes the key has been curtailed by distance and magnitude, and colony recovery from points leading to our finding: geographical barriers. plague is slow or nonexistent. (1) Historic data indicate a decline (iii) The two portions of the range are Distributional data indicate that the from 24,000,000 ac (9,700,000 ha) of separated by mountain ranges that species’ status in this portion of its occupied habitat to between 340,000 almost completely limit prairie dog range is characterized by lower and 500,000 ac (136,000 to 200,000 ha). movement between them. occupancy, smaller colony sizes, and (2) Recent data indicate that (iv) Populations within the montane fragmented and isolated colonies that approximately 3.6 percent of potential portion of the range are separated from impede recovery and persistence of Gunnison’s prairie dog habitat is each other by four mountain ranges and populations. Reliable data regarding the occupied in the montane portion of the several large rivers, which preclude status of the Gunnison’s prairie dog are range, as compared to 18.3 percent repopulation after plague epizootics. predominantly in the form of percent occupancy in the prairie portion of the (v) Some entire population areas occupancy studies, which indicate range. within montane range are now nearly significantly lower occupancy in (3) The Gunnison’s prairie dog devoid of Gunnison’s prairie dogs. montane habitat (for Colorado, occupies two genetically important (vi) Plague appears to be more approximately 3.6 percent versus 18.3 areas of its range (prairie and montane prevalent in the montane portion of the percent in prairie habitat). For example, portions). The two portions have range, possibly due to greater flea the South Park population area, which different geographical features and populations that thrive in moister comprises nearly 15 percent of the different responses to plague. climates. species’ habitat in Colorado, is nearly (4) Plague has resulted in large We determined that the magnitude of devoid of the species. Within the four reductions in prairie dogs and occupied threats affecting the Gunnison’s prairie montane population areas in Colorado, habitat within both portions of the dog in the montane portion of its range prairie dog complexes exist within only range. The prairie portion of the range is ‘‘high,’’ because plague is one, and those complexes are few and is responding to plague by recolonizing significantly affecting the remaining small. With little or no metapopulation affected populations. Within the small, isolated populations, and plague structure, an overall decline in montane portion of the range, the plague epizootics can extirpate populations persistence is apparent in the montane response is more significant (large there within a short timeframe (3 to 10 habitat. population losses, loss of all years); metapopulation structure in the Populations within montane habitat metapopulation structure, nearly no prairie portion of the range exists, have three distinct disadvantages in recolonization occurring, and entire facilitating recolonization when resisting the effects of plague: (1) A population areas nearly devoid of populations are extirpated. We find that higher frequency of epizootics due to prairie dogs). the threat posed by plague is the moister montane climate that is (5) We determined that the ‘‘imminent’’ because plague epizootics conducive to higher abundance of fleas Gunnison’s prairie dog is warranted for are known to be occurring and the that spread plague; (2) smaller listing in the montane portion because: effects are measurable. Therefore, populations that cannot recover in (A) The montane portion of the range pursuant to our September 21, 1983 (48 numbers from plague epizootics; and (3) is significant to the species’ viability (it FR 43098) Listing and Recovery Priority isolated populations and little or no represents approximately 40 percent of Guidelines, we assign a LPN of 2 to this metapopulation structure, due to the species’ habitat; populations are portion of the species’ range. reduced population sizes from past adapted to unique, montane habitat; and We reviewed the available plague epizootics and montane these animals are genetically unique). information to determine if existing and

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foreseeable threats to the Gunnison’s month finding, without a proposed rule, would prepare and issue a listing prairie dog within montane habitat are has ranged from approximately $11,000 proposal or make a ‘‘warranted but of sufficient extent and magnitude to for one species with a restricted range precluded’’ finding for a given species. require emergency listing as threatened and involving a relatively The Conference Report accompanying or endangered. We have determined that uncomplicated analysis to $305,000 for Public Law 97–304, which established an emergency listing is not warranted another species that is wide-ranging and the current statutory deadlines and the for this species at this time, because involving a complex analysis. warranted-but-precluded finding, states populations are currently not threatened We cannot spend more than is (in a discussion on 90-day petition in the prairie portion of the range, and appropriated for the Listing Program findings that by its own terms also because emergency listing would not without violating the Anti-Deficiency covers 12-month findings) that the lessen the effects from plague, which is Act (see 31 U.S.C. 1341(a)(1)(A)). In deadlines were ‘‘not intended to allow the significant threat in the montane addition, in FY 1998 and for each fiscal the Secretary to delay commencing the portion of the range. year since then, Congress has placed a rulemaking process for any reason other statutory cap on funds which may be than that the existence of pending or Preclusion and Expeditious Progress expended for the Listing Program, equal imminent proposals to list species Preclusion is a function of the listing to the amount expressly appropriated subject to a greater degree of threat priority of a species in relation to the for that purpose in that fiscal year. This would make allocation of resources to resources that are available and cap was designed to prevent funds such a petition [that is, for a lower- competing demands for those resources. appropriated for other functions under ranking species] unwise.’’ Thus, in any given fiscal year (FY), the Act (for example, recovery funds for In FY 2008, expeditious progress is multiple factors dictate whether it will removing species from the Lists), or for that amount of work that can be be possible to undertake work on a other Service programs, from being used achieved with $8,206,940, which is the proposed listing regulation or whether for Listing Program actions (see House amount of money that Congress promulgation of such a proposal is Report 105–163, 105th Congress, 1st appropriated for the Listing Program at warranted but precluded by higher- Session, July 1, 1997). this time (that is, the portion of the priority listing actions. Recognizing that designation of Listing Program funding not related to The resources available for listing critical habitat for species already listed critical habitat designations for species actions are determined through the would consume most of the overall that are already listed). Our process is annual Congressional appropriations Listing Program appropriation, Congress to make our determinations of process. The appropriation for the also put a critical habitat subcap in preclusion on a nationwide basis to Listing Program is available to support place in FY 2002 and has retained it ensure that the species most in need of work involving the following listing each subsequent year to ensure that listing will be addressed first and also actions: proposed and final listing rules; some funds are available for other work because we allocate our listing budget 90-day and 12-month findings on in the Listing Program: ‘‘The critical on a nationwide basis. The $8,206,940 petitions to add species to the Lists of habitat designation subcap will ensure for listing activities (that is, the portion Endangered and Threatened Wildlife that some funding is available to of the Listing Program funding not and Plants or to change the status of a address other listing activities’’ (House related to critical habitat designations species from threatened to endangered; Report No. 107–103, 107th Congress, 1st for species that already are listed) will annual determinations on prior Session, June 19, 2001). In FY 2002 and be used to fund work in the following ‘‘warranted but precluded’’ petition each year until FY 2006, the Service has categories: compliance with court orders findings as required under section had to use virtually the entire critical and court-approved settlement 4(b)(3)(C)(i) of the Act; proposed and habitat subcap to address court- agreements requiring that petition final rules designating critical habitat; mandated designations of critical findings or listing determinations be and litigation-related, administrative, habitat, and consequently none of the completed by a specific date; section 4 and program management functions critical habitat subcap funds have been (of the Act) listing actions with absolute (including preparing and allocating available for other listing activities. In statutory deadlines; essential litigation- budgets, responding to Congressional FY 2007, we were able to use some of related, administrative, and program and public inquiries, and conducting the critical habitat subcap funds to fund management functions; and high- public outreach regarding listing and proposed listing determinations for priority listing actions. The allocations critical habitat). The work involved in high-priority candidate species; we for each specific listing action are preparing various listing documents can expect to also be able to do this in FY identified in the Service’s FY 2008 Draft be extensive and may include, but is not 2008. Allocation Table (part of our limited to: gathering and assessing the Thus, through the listing cap, the administrative record). We are working best scientific and commercial data critical habitat subcap, and the amount on completing our allocation at this available and conducting analyses used of funds needed to address court- time. More funds are available in FY as the basis for our decisions; writing mandated critical habitat designations, 2008 than in previous years to work on and publishing documents; and Congress and the courts have in effect listing actions that are not the subject of obtaining, reviewing, and evaluating determined the amount of money court orders or court-approved public comments and peer review available for other listing activities. settlement agreements. comments on proposed rules and Therefore, the funds in the listing cap, Our decision that a proposed rule to incorporating relevant information into other than those needed to address list the montane portion of the final rules. The number of listing court-mandated critical habitat for Gunnison’s prairie dog is warranted but actions that we can undertake in a given already listed species, set the limits on precluded includes consideration of its year also is influenced by the our determinations of preclusion and listing priority. In accordance with complexity of those listing actions; that expeditious progress. guidance we published on September is, more complex actions generally are Congress also recognized that the 21, 1983, we assign an LPN to each more costly. For example, during the availability of resources was the key candidate species (48 FR 43098). Such past several years, the cost (excluding element in deciding whether, when a priority ranking guidance system is publication costs) for preparing a 12- making a 12-month petition finding, we required under section 4(h)(3) of the Act

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(16 U.S.C. 1533(h)(3)). Using this threat rank (substantial, imminent As explained above, a determination guidance, we assign each candidate an threats), and currently with fewer than that listing is warranted but precluded LPN of 1 to 12, depending on the 50 individuals, or fewer than 4 must also demonstrate that expeditious magnitude of threats (high vs. moderate populations, comprise a list of progress is being made to add or remove to low), immediacy of threats (imminent approximately 40 candidate species qualified species to and from the Lists or non-imminent), and taxonomic status (‘‘Top 40’’). These 40 candidate species of Endangered and Threatened Wildlife of the species, in order of priority have the highest priority to receive and Plants. (We note that we do not (monotypic genus (a species that is the funding to work on a proposed listing discuss specific actions taken on sole member of a genus), species, determination. To be more efficient in progress towards removing species from subspecies, distinct population segment, our listing process, as we work on the Lists because that work is conducted or significant portion of the range). The proposed rules for these species in the using appropriations for our Recovery lower the listing priority number, the next several years, we are preparing program, a separately budgeted higher the listing priority (that is, a multi-species proposals when component of the Endangered Species species with an LPN of 1 would have appropriate, and these may include Program. As explained above in our the highest listing priority). We currently have more than 120 species with lower priority if they description of the statutory cap on species with an LPN of 2. Therefore, we overlap geographically or have the same Listing Program funds, the Recovery further rank the candidate species with threats as a species with an LPN of 2. Program funds and actions supported by an LPN of 2 by using the following In addition, available staff resources are them cannot be considered in extinction-risk type criteria: also a factor in determining high- determining expeditious progress made International Union for the priority species provided with funding. in the Listing Program.) As with our Conservation of Nature and Natural Finally, proposed rules for ‘‘precluded’’ finding, expeditious Resources (IUCN) Red list status/rank, reclassification of threatened species to progress in adding qualified species to Heritage rank (provided by endangered are lower priority, since the the Lists is a function of the resources NatureServe), Heritage threat rank listing of the species already affords the available and the competing demands (provided by NatureServe), and species protection of the Act and implementing for those funds. Our expeditious currently with fewer than 50 regulations. We assigned the montane progress in FY 2007 in the Listing individuals, or 4 or fewer populations. portion of the Gunnison’s prairie dog an Program, up to the date of making this Those species with the highest IUCN LPN of 5, based on our finding that the finding for the Gunnison’s prairie dog, rank (critically endangered), the highest species faces threats of high magnitude included preparing and publishing the Heritage rank (G1), the highest Heritage that are not imminent. following determinations:

FY 2007 COMPLETED LISTING ACTIONS

Publication date Title Actions FR pages

10/11/2006 ...... Withdrawal of the Proposed Rule To List the Cow Head Tui Final withdrawal, Threats elimi- 71 FR 59700–59711 Chub (Gila biocolor vaccaceps) as Endangered. nated. 10/11/2006 ...... Revised 12-Month Finding for the Beaver Cave Beetle Notice of 12-month petition 71 FR 59711–59714 (Pseudanophthalmus major). finding, Not warranted. 11/14/2006 ...... 12-Month Finding on a Petition To List the Island Marble But- Notice of 12-month petition 71 FR 66292–66298 terfly (Euchloe ausonides insulanus) as Threatened or En- finding, Not warranted. dangered. 11/14/2006 ...... 90-Day Finding for a Petition To List the Kennebec River Popu- Notice of 90-day petition find- 71 FR 66298–66301 lation of Anadromous Atlantic Salmon as Part of the Endan- ing, Substantial. gered Gulf of Maine Distinct Population Segment. 11/21/2006 ...... 90-Day Finding on a Petition To List the Columbian Sharp- Notice of 90-day petition find- 71 FR 67318–67325 Tailed Grouse as Threatened or Endangered. ing, Not substantial. 12/5/2006 ...... 90-Day Finding on a Petition To List the Tricolored Blackbird as Notice of 90-day petition find- 71 FR 70483–70492 Threatened or Endangered. ing, Not substantial. 12/6/2006 ...... 12-Month Finding on a Petition To List the Cerulean Warbler Notice of 12-month petition 71 FR 70717–70733 (Dendroica cerulea) as Threatened with Critical Habitat. finding, Not warranted. 12/6/2006 ...... 90-Day Finding on a Petition To List the Upper Tidal Potomac Notice of 90-day petition find- 71 FR 70715–70717 River Population of the Northern Water Snake (Nerodia ing, Not substantial. sipedon) as an Endangered Distinct Population Segment. 12/14/2006 ...... 90-Day Finding on a Petition To Remove the Uinta Basin Notice of 5-year review, Initi- 71 FR 75215–75220 Hookless Cactus From the List of Endangered and Threat- ation. ened Plants; 90-Day Finding on a Petition To List the Notice of 90-day petition find- Pariette Cactus as Threatened or Endangered. ing, Not substantial. Notice of 90-day petition find- ing, Substantial. 12/19/2006 ...... Withdrawal of Proposed Rule To List Penstemon grahamii Notice of withdrawal, More 71 FR 76023–76035 (Graham’s beardtongue) as Threatened With Critical Habitat. abundant than believed, or diminished threats. 12/19/2006 ...... 90-Day Finding on Petitions To List the Mono Basin Area Pop- Notice of 90-day petition find- 71 FR 76057–76079 ulation of the Greater Sage-Grouse as Threatened or Endan- ing, Not substantial. gered. 1/9/2007 ...... 12-Month petition finding and Proposed Rule To List the Polar Notice of 12-month petition 72 FR 1063–1099 Bear (Ursus maritimus) as Threatened Throughout Its finding, Warranted. Range; Proposed Rule. Proposed Listing, Threatened ..

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FY 2007 COMPLETED LISTING ACTIONS—Continued

Publication date Title Actions FR pages

1/10/2007 ...... Endangered and Threatened Wildlife and Plants; Clarification of Clarification of findings ...... 72 FR 1186–1189 Significant Portion of the Range for the Contiguous United States Distinct Population Segment of the Canada Lynx. 1/12/2007 ...... Withdrawal of Proposed Rule To List Lepidium papilliferum Notice of withdrawal, More 72 FR 1621–1644 (Slickspot Peppergrass). abundant than believed, or diminished threats. 2/2/2007 ...... 12-Month Finding on a Petition To List the American Eel as Notice of 12-month petition 72 FR 4967–4997 Threatened or Endangered. finding, Not warranted. 2/13/2007 ...... 90-Day Finding on a Petition To List the Jollyville Plateau Sala- Notice of 90-day petition find- 72 FR 6699–6703 mander as Endangered. ing, Substantial. 2/13/2007 ...... 90-Day Finding on a Petition To List the San Felipe Gambusia Notice of 90-day petition find- 72 FR 6703–6707 as Threatened or Endangered. ing, Not substantial. 2/14/2007 ...... 90-Day Finding on a Petition To List Astragalus debequaeus Notice of 90-day petition find- 72 FR 6998–7005 (DeBeque milkvetch) as Threatened or Endangered. ing, Not substantial. 2/21/2007 ...... 90-Day Finding on a Petition To Reclassify the Utah Prairie Notice of 5-year review, Initi- 72 FR 7843–7852 Dog From Threatened to Endangered and Initiation of a 5- ation. Year Review. Notice of 90-day petition find- ing, Not substantial. 3/8/2007 ...... 90-Day Finding on a Petition To List the Monongahela River Notice of 90-day petition find- 72 FR 10477–10480 Basin Population of the Longnose Sucker as Endangered. ing, Not substantial. 03/29/2007 ...... 90-Day Finding on a Petition To List the Siskiyou Mountains Notice of 90-day petition find- 72 FR 14750–14759 Salamander and Scott Bar Salamander as Threatened or En- ing, Substantial. dangered. 04/24/2007 ...... Revised 12-Month Finding for Upper Missouri River Distinct Notice of 12-month petition 72 FR 20305–20314 Population Segment of Fluvial Arctic Grayling. finding, Not warranted. 05/02/2007 ...... 12-Month Finding on a Petition To List the Sand Mountain Blue Notice of 12-month petition 72 FR 24253–24263 Butterfly (Euphilotes pallescens ssp. arenamontana) as finding, Not warranted. Threatened or Endangered with Critical Habitat. 05/22/2007 ...... Status of the Rio Grande Cutthroat Trout ...... Notice of Review ...... 72 FR 28864–28665 05/30/2007 ...... 90-Day Finding on a Petition To List the Mt. Charleston Blue Notice of 90-day petition find- 72 FR 29933–29941 Butterfly as Threatened or Endangered. ing, Substantial. 06/05/2007 ...... 12-Month Finding on a Petition To List the Wolverine as Notice of Review ...... 72 FR 31048–31049 Threatened or Endangered. 06/06/2007 ...... 90-Day Finding on a Petition To List the Yellow-Billed Loon as Notice of 90-day petition find- 72 FR 31256–31264 Threatened or Endangered. ing, Substantial. 06/13/2007 ...... 12-Month Finding for a Petition To List the Colorado River Cut- Notice of 12-month petition 72 FR 32589–32605 throat Trout as Threatened or Endangered. finding, Not warranted. 06/25/2007 ...... 12-Month Finding on a Petition To List the Sierra Nevada Dis- Notice of amended 12-month 72 FR 34657–34661 tinct Population Segment of the Mountain Yellow-Legged petition finding, Warranted Frog (Rana muscosa). but precluded. 07/05/2007 ...... 12-Month Finding on a Petition To List the Casey’s June Beetle Notice of 12-month petition 72 FR 36635–36646 (Dinacoma caseyi) as Endangered With Critical Habitat. finding, Warranted but pre- cluded. 08/15/2007 ...... 90-Day Finding on a Petition To List the Yellowstone National Notice of 90-day petition find- 72 FR 45717–45722 Park Bison Herd as Endangered. ing, Not substantial. 08/16/2007 ...... 90-Day Finding on a Petition To List Astragalus anserinus Notice of 90-day petition find- 72 FR 46023–46030 (Goose Creek milk-vetch) as Threatened or Endangered. ing, Substantial. 8/28/2007 ...... 12-Month Finding on a Petition To List the Gunnison’s Prairie Notice of Review ...... 72 FR 49245–49246 Dog as Threatened or Endangered. 9/11/2007 ...... 90-Day Finding on a Petition To List Kenk’s Amphipod, Virginia Notice of 90-day petition find- 72 FR 51766–51770 Well Amphipod, and the Copepod Acanthocyclops ing, Not substantial. columbiensis as Endangered. 9/18/2007 ...... 12-month Finding on a Petition To List Sclerocactus Notice of 12-month petition 72 FR 53211–53222 brevispinus (Pariette cactus) as an Endangered or Threat- finding for uplisting, War- ened Species; Taxonomic Change From Sclerocactus ranted but precluded. glaucus to Sclerocactus brevispinus, S. glaucus, and S. wetlandicus.

In FY 2007, we provided funds to Chamaesyce eleanoriae, Chamaesyce pumila, Lysimachia daphnoides, work on proposed listing remyi var. kauaiensis, Chamaesyce Melicope degeneri, Melicope paniculata, determinations for the following high- remyi var. remyi, Charpentiera Melicope puberula, Myrsine mezii, priority species: 3 southeastern aquatic densiflora, Cyanea eleeleensis, Cyanea Pittosporum napaliense, Platydesma species (Georgia pigtoe, interrupted kuhihewa, Cyrtandra oenobarba, rostrata, Pritchardia hardyi, Psychotria rocksnail, and rough hornsnail), 2 Oahu Dubautia imbricata ssp. imbricata, grandiflora, Psychotria hobdyi, plants (Doryopteris takeuchii, Melicope Dubautia plantaginea ssp. magnifolia, Schiedea attenuata, Stenogyne kealiae), hiiakae), 31 Kauai species (Kauai Dubautia waialealae, Geranium 4 Hawaiian damselflies (Megalagrion creeper, Drosophila attigua, Astelia kauaiense, Keysseria erici, Keysseria nesiotes, Megalagrion leptodemas, waialealae, Canavalia napaliensis, helenae, Labordia helleri, Labordia Megalagrion oceanicum, Megalagrion

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pacificum), and one Hawaiian plant are now including an additional 17 several other determinations listed (Phyllostegia hispida (no common species in the Kauai species proposed below, which we funded in FY 2007 name)). In FY 2008, we are continuing listing determination package). In and are scheduled to complete in FY to work on these listing proposals (we addition, we are continuing to work on 2008.

ACTIONS FUNDED IN FY 2007 THAT HAVE YET TO BE COMPLETED

Species Action

Actions Subject to Court Order/Settlement Agreement

Wolverine ...... 12-month petition finding (remand). Western sage grouse ...... 90-day petition finding (remand). Rio Grande cutthroat trout ...... Candidate assessment (remand).

Actions with Statutory Deadlines

Polar bear ...... Final listing determination. Ozark chinquapin ...... 90-day petition finding. Tucson shovel-nosed snake ...... 90-day petition finding. Gopher tortoise—Florida population ...... 90-day petition finding. Sacramento valley tiger beetle ...... 90-day petition finding. Eagle lake trout ...... 90-day petition finding. Smooth billed ani ...... 90-day petition finding. Mojave ground squirrel ...... 90-day petition finding. Gopher Tortoise—eastern population ...... 90-day petition finding. Bay Springs salamander ...... 90-day petition finding. Tehachapi slender salamander ...... 90-day petition finding. Coaster brook trout ...... 90-day petition finding. Mojave fringe-toed lizard ...... 90-day petition finding. Evening primrose ...... 90-day petition finding. Palm Springs pocket mouse ...... 90-day petition finding. Northern leopard frog ...... 90-day petition finding. Shrike, Island loggerhead ...... 90-day petition finding. Cactus ferruginous pygmy owl ...... 90-day petition finding.

Our expeditious progress so far in FY 2008 in the Listing Program, includes preparing and publishing the following:

FY 2008 COMPLETED LISTING ACTIONS

Publication date Title Actions FR Pages

10/09/2007 ...... 90-Day Finding on a Petition to List the Black-Footed Albatross Notice of 90-day Petition Find- 72 FR 57278–57283 (Phoebastria nigripes) as Threatened or Endangered. ing, Substantial. 10/09/2007 ...... 90-Day Finding on a Petition To List the Giant Palouse Earth- Notice of 90-day Petition Find- 72 FR 57273–57276 worm as Threatened or Endangered. ing, Not substantial. 10/23/2007 ...... 90-Day Finding on a Petition To List the Mountain Whitefish Notice of 90-day Petition Find- 72 FR 59983–59989 (Prosopium williamsoni) in the Big Lost River, ID, as Threat- ing, Not substantial. ened or Endangered. 10/23/2007 ...... 90-Day Finding on a Petition To List the Summer-Run Kokanee Notice of 90-day Petition Find- 72 FR 59979–59983 Population in Issaquah Creek, WA, as Threatened or Endan- ing, Not substantial. gered. 11/08/2007 ...... Response to Court on Significant Portion of the Range, and Response to Court ...... 72 FR 63123–63140 Evaluation of Distinct Population Segments, for the Queen Charlotte Goshawk. 12/13/07 ...... 12-Month Finding on a Petition To List the Jollyville Plateau Notice of 12-month Petition 72 FR 71039–71054 salamander (Eurycea tonkawae) as Endangered With Critical Finding, Warranted but Pre- Habitat. cluded. 1/08/08 ...... 90-Day Finding on a Petition To List the Pygmy Rabbit Notice of 90-day Petition Find- 73 FR 1312–1313 (Brachylagus idahoensis) as Threatened or Endangered. ing, Substantial. 1/24/2008 ...... 12-Month Finding on a Petition To List the Siskiyou Mountains Notice of 12-month Petition 73 FR 4379–4418 Salamander (Plethodon stormi) and Scott Bar Salamander Finding, Not Warranted. (Plethodon asupak) as Threatened or Endangered.

Our expeditious progress also top section of the table under a deadline Actions in the bottom section of the includes work on listing actions, which set by a court. Actions in the middle table are high priority listing actions, we are funding in FY 2008. These section of the table are being conducted which include at least one or more actions are listed below. We are to meet statutory timelines, that is, species with an LPN of 2, available staff conducting work on those actions in the timelines required under the Act. resources, and when appropriate,

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species with a lower priority if they threats as the species with the high overlap geographically or have the same priority.

ACTIONS ANTICIPATED TO BE FUNDED IN FY 2008 THAT HAVE YET TO BE COMPLETED

Species Action

Actions Subject to Court Order/Settlement Agreement

Bonneville cutthroat trout ...... 12-month petition finding (remand).

Actions With Statutory Deadlines

Polar bear ...... Final listing determination. 3 Southeastern aquatic species ...... Final listing. Phyllostegia hispida ...... Final listing. Yellow-billed loon ...... 12-month petition finding. Black-footed albatross ...... 12-month petition finding. Mount Charleston blue butterfly ...... 12-month petition finding. Goose Creek milk-vetch ...... 12-month petition finding. White-tailed prairie dog ...... 12-month petition finding. Mono Basin sage grouse (vol. remand) ...... 90-day petition finding. Ashy storm petrel ...... 90-day petition finding. Longfin smelt—San Fran. Bay population ...... 90-day petition finding. Black-tailed prairie dog ...... 90-day petition finding. Lynx (include New Mexico in listing) ...... 90-day petition finding. Wyoming pocket gopher ...... 90-day petition finding. Llanero coqui ...... 90-day petition finding. Least chub ...... 90-day petition finding. American pika ...... 90-day petition finding. Dusky tree vole ...... 90-day petition finding. Sacramento Mts. checkerspot butterfly ...... 90-day petition finding. Kokanee—Lake Sammamish population ...... 90-day petition finding. 206 species ...... 90-day petition finding. 475 Southwestern species ...... 90-day petition finding.

High Priority Listing Actions

31 Kauai species 1 ...... Proposed listing. 8 packages of high-priority candidate species ...... Proposed listing. 1 Funds used for this listing action were also provided in FY 2007.

We have endeavored to make our listing of this species, we will act DEPARTMENT OF THE INTERIOR listing actions as efficient and timely as immediately to provide additional possible, given the requirements of the protection. Fish and Wildlife Service relevant law and regulations, and constraints relating to workload and References 50 CFR Part 17 personnel. We are continually A complete list of all references cited [FWS–R8–ES–2008–0014; 92210–1117– considering ways to streamline herein is available upon request from 0000–B4] processes or achieve economies of scale, the Western Colorado Field Office (see such as by batching related actions RIN 1018–AV05 ADDRESSES). together. Given our limited budget for Endangered and Threatened Wildlife implementing section 4 of the Act, these Author and Plants; Designation of Critical actions described above collectively Habitat for the Sierra Nevada Bighorn constitute expeditious progress. The primary authors of this document are staff located at the Colorado Field Sheep (Ovis canadensis californiana) and Proposed Taxonomic Revision Conclusion Office (see ADDRESSES). We will add the montane portion of Authority AGENCY: Fish and Wildlife Service, the Gunnison’s prairie dog to the list of Interior. The authority for this action is the candidate species. We intend any listing ACTION: Proposed rule; reopening of action for the species to be as accurate Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.). comment period, notice of availability as possible by reflecting the best of draft economic analysis, and available information. Therefore, we Dated: January 29, 2008. amended required determinations. will continue to accept additional H. Dale Hall, information and comments on the status Director, U.S. Fish and Wildlife Service. SUMMARY: We, the U.S. Fish and of and threats to this species from all [FR Doc. 08–493 Filed 2–4–08; 8:45 am] Wildlife Service (Service), announce the concerned governmental agencies, the reopening of the public comment period scientific community, industry, or any BILLING CODE 4310–55–P on the proposed designation of critical other interested party concerning this habitat for the Sierra Nevada bighorn finding. If an emergency situation sheep (Ovis canadensis californiana) develops that warrants an emergency and proposed taxonomic revision under

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