Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List Desert Massasauga as Endangered or Threatened and To Designate Critical Habitat, 47583-47587 [2012-19476]

Download as PDF Federal Register / Vol. 77, No. 154 / Thursday, August 9, 2012 / Proposed Rules DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS–R2–ES–2012–0057; 4500030114] Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List Desert Massasauga as Endangered or Threatened and To Designate Critical Habitat Fish and Wildlife Service, Interior. ACTION: Notice of petition finding and initiation of status review. AGENCY: We, the U.S. Fish and Wildlife Service (Service), announce a 90-day finding on a petition to list desert massasauga (Sistrurus catenatus edwardsii), a rattlesnake found in the southwestern United States, as endangered or threatened under the Endangered Species Act of 1973, as amended (Act), and to designate critical habitat. Based on our review, we find that the petition presents substantial scientific or commercial information indicating that listing desert massasauga may be warranted. We will initiate a review of the status of this subspecies to determine if listing is warranted. We are requesting scientific and commercial data and other information regarding this subspecies. Based on the status review, we will issue a 12-month finding on the petition, which will address whether the petitioned action is warranted as provided in section 4(b)(3)(B) of the Act. DATES: We request that we receive information on or before October 9, 2012. The deadline for submitting an electronic comment using the Federal eRulemaking Portal (see ADDRESSES section, below) is 11:59 p.m. Eastern Time on this date. After October 9, 2012, you must submit information directly to the Division of Policy and Directives Management (see ADDRESSES section, below). Please note that we might not be able to address or incorporate information that we receive after the above requested date. ADDRESSES: You may submit information by one of the following methods: (1) Electronically: Go to the Federal eRulemaking Portal: https:// www.regulations.gov. Search for Docket No. FWS–R2–ES–2012–0057. (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS–R2–ES–2012– 0057; Division of Policy and Directives Management; U.S. Fish and Wildlife mstockstill on DSK4VPTVN1PROD with PROPOSALS SUMMARY: VerDate Mar<15>2010 16:15 Aug 08, 2012 Jkt 226001 Service; 4401 N. Fairfax Drive, MS 2042–PDM; Arlington, VA 22203. We will not accept emails or faxes. We will post all information we receive on https://www.regulations.gov. This generally means that we will post any personal information you provide us (see the Request for Information section below for more details). FOR FURTHER INFORMATION CONTACT: Michelle Shaughnessy, Assistant Regional Director, Southwest Regional Office, 500 Gold Ave. SW., Room 6034, Albuquerque, NM 87102; by telephone at 505–248–6920; or by facsimile at 505–248–6788. If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800–877–8339. SUPPLEMENTARY INFORMATION: Request for Information When we make a finding that a petition presents substantial information indicating that listing a species may be warranted, we are required to promptly review the status of the species (status review). For the status review to be complete and based on the best available scientific and commercial information, we request information on desert massasauga from governmental agencies, Native American tribes, the scientific community, industry, and any other interested parties. We seek information on: (1) The subspecies’ biology, range, and population trends, including: (a) Habitat requirements for reproduction, germination, and survival; (b) Genetics and taxonomy; (c) Historical and current range, including distribution patterns; (d) Historical and current population levels, and current and projected trends; and (e) Past and ongoing conservation measures for the species, its habitat, or both. (2) The factors that are the basis for making a listing, delisting, or downlisting determination for a species under section 4(a) of the Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.), which are: (a) The present or threatened destruction, modification, or curtailment of its habitat or range; (b) Overutilization for commercial, recreational, scientific, or educational purposes; (c) Disease or predation; (d) The inadequacy of existing regulatory mechanisms; or (e) Other natural or manmade factors affecting its continued existence. PO 00000 Frm 00026 Fmt 4702 Sfmt 4702 47583 If, after the status review, we determine that listing desert massasauga is warranted, we will propose critical habitat (see definition in section 3(5)(A) of the Act), under section 4 of the Act, to the maximum extent prudent and determinable at the time we propose to list the species. Therefore, we request data and information on: (1) What may constitute ‘‘physical or biological features essential to the conservation of the species’’ within the geographical range currently occupied by the subspecies; (2) Where these features are currently found; (3) Whether any of these features may require special management considerations or protection; (4) Specific areas outside the geographical area occupied by the subspecies that are ‘‘essential for the conservation of the species;’’ and (5) What, if any, critical habitat you think we should propose for designation if the subspecies is proposed for listing, and why such habitat meets the requirements of section 4 of the Act. Please include sufficient information with your submission (such as scientific journal articles or other publications) to allow us to verify any scientific or commercial information you include. Submissions merely stating support for or opposition to the action under consideration without providing supporting information, although noted, will not be considered in making a determination. Section 4(b)(1)(A) of the Act directs that determinations as to whether any species is an endangered or threatened species must be made ‘‘solely on the basis of the best scientific and commercial data available.’’ You may submit your information concerning this status review by one of the methods listed in the ADDRESSES section. If you submit information via https://www.regulations.gov, your entire submission—including any personal identifying information—will be posted on the Web site. If you submit a hardcopy that includes personal identifying information, you may request at the top of your document that we withhold this personal identifying information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy submissions on https:// www.regulations.gov. Information and supporting documentation that we received and used in preparing this finding are available for you to review at https:// www.regulations.gov, or you may make an appointment during normal business hours at the U.S. Fish and Wildlife E:\FR\FM\09AUP1.SGM 09AUP1 47584 Federal Register / Vol. 77, No. 154 / Thursday, August 9, 2012 / Proposed Rules Service, Southwest Regional Office (see FOR FURTHER INFORMATION CONTACT). mstockstill on DSK4VPTVN1PROD with PROPOSALS Background Section 4(b)(3)(A) of the Act requires that we make a finding on whether a petition to list, delist, or reclassify a species presents substantial scientific or commercial information indicating that the petitioned action may be warranted. We are to base this finding on information provided in the petition, supporting information submitted with the petition, and information otherwise available in our files. To the maximum extent practicable, we are to make this finding within 90 days of our receipt of the petition and publish our notice of the finding promptly in the Federal Register. Our standard for substantial scientific or commercial information within the Code of Federal Regulations (CFR) with regard to a 90-day petition finding is ‘‘that amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted’’ (50 CFR 424.14(b)). If we find that substantial scientific or commercial information was presented, we are required to promptly conduct a species status review, which we subsequently summarize in our 12month finding. The ‘‘substantial information’’ standard for a 90-day finding differs from the Act’s ‘‘best scientific and commercial data’’ standard that applies to a status review to determine whether a petitioned action is warranted. A 90day finding does not constitute a status review under the Act. In a 12-month finding, we will announce our determination as to whether a petitioned action is warranted after we have completed a thorough status review of the species, which is conducted following a substantial 90day finding. Because the Act’s standards for 90-day findings and status reviews conducted for a 12-month finding on a petition are different, as described above, a substantial 90-day finding does not mean that our status review and resulting determination will result in a warranted finding. Petition History On November 1, 2010, we received a petition dated October 28, 2010, from the WildEarth Guardians, requesting that desert massasauga be listed as endangered or threatened and critical habitat be designated under the Act. Alternatively, the petitioner requested listing of a distinct population segment of desert massasauga in Colorado, Kansas, and Oklahoma. The petition clearly identified itself as such and VerDate Mar<15>2010 16:15 Aug 08, 2012 Jkt 226001 included the requisite identification information for the petitioner, as required by 50 CFR 424.14(a). In a December 1, 2011, letter to the WildEarth Guardians, we responded that we reviewed the information presented in the petition and determined that issuing an emergency regulation temporarily listing the subspecies under section 4(b)(7) of the Act was not warranted. We also stated that we intended to complete an initial finding in Fiscal Year 2012 as to whether this petition contains substantial information indicating that the action may be warranted. This 90day finding addresses the October 28, 2010, petition. Species Information Taxonomy and Description The desert massasauga (Sistrurus catenatus edwardsii) is a rattlesnake (Family Viperidae) classified as a subspecies of massasauga (Sistrurus catenatus) (Conant and Collins 1991, p. 232; Ernst and Ernst 2003, pp. 552–553; Collins and Taggart 2009, p. 32). As a widely recognized subspecies, it is a listable entity under the Act. Mackessy (2005, p. 10) described the color of desert massasauga as gray to light brown, with 37 to 40 darker brown saddles or semicircular blotches, outlined in black, forming a regular pattern on the dorsal surface. A prominent dark brown to black stripe extends from the eye to the angle of the jaw, and a lyre-shaped or paired irregular set of stripes extends from the dorsal surface of the head to the first body blotch. The base of the rattle on the tail is typically black, but in neonates (young snakes), the tip is yellow. The desert massasauga is relatively small compared to other rattlesnakes, reaching a maximum adult total length of 588 millimeters (mm) (23 inches (in)) (Holycross 2001, p. 59), with an average length of about 380 mm (15 in) (Mackessy 2005, p. 27). The desert massasauga is venomous, and the venom is used to acquire prey and is toxic to humans. However, due to its small adult size, venom yields are low, and bites to humans, although potentially serious, are not likely to be life-threatening (Mackessy 2005, p. 10). The probability of a desert massasauga biting a human is also very low because there is only a small chance of encountering the snake due to its nocturnality; spotty distribution; and generally cryptic, elusive, and nonaggressive behavior (Werler and Dixon 2000, p. 404). PO 00000 Frm 00027 Fmt 4702 Sfmt 4702 Habitat The desert massasauga occurs in a variety of grassland and shrubland habitats, including shortgrass prairie, sandsage grasslands, shinnery oak, Chihuahuan desert, and occasionally sand dune habitat (Degenhardt et al. 1996, p. 356; Hobert et al. 2004, p. 323; Mackessy 2007, p. 2). Studies in Colorado have shown it inhabits primarily shortgrass prairie habitat with Artemisia filifolia (sand sage), Buchloe dactyloides (buffalograss), and Bouteloua gracilis (blue grama) below about 1,500 meters (5,000 feet) in elevation. Although the species is adapted to xeric (dry) conditions, the subspecies is most abundant in areas of prairie with more mesic (moist) conditions (Mackessy 2005, p. 23). The snake uses grasses for capturing prey and avoiding predators, as these areas provide protective cover. The subspecies is not often found in scrub or shrub habitats in most parts of its range. Life History The biology of the desert massasauga has been studied in some detail in some parts of its range. The snakes hibernate from October to mid-April in Colorado (Hobert et al. 2004, p. 324), and from November to March in New Mexico (Degenhardt et al. 1996, p. 357) with presumably similar timeframes of hibernation in other parts of its range. They commonly use rodent burrows for hibernation and as birthing sites (Mackessy 2005, pp. 16–17, 23; Mackessy 2007, p. 8). They are mainly nocturnal and may migrate up to 2 kilometers (km) (1.2 miles (mi)) seasonally between locations used for winter hibernation and those used during active periods (Ernst and Ernst 2003, p. 554; Mackessy 2005, pp. 20– 21). Desert massasauga feed on a wide variety of prey, including lizards, small mammals, and centipedes (Holycross and Mackessy 2002, p. 456). Females have been observed to give birth in the summer to between 4 and 8 young (Hobert et al. 2004, pp. 324–325; Mackessy 2005, p. 29), and may not reproduce every year (Goldberg and Holycross 1999, p. 531). Most adults collected in the field were estimated to be 4 years old or less, though members of the subspecies have lived more than 14 years in captivity. Distribution and Abundance The range of desert massasauga is reported with some variation in published accounts, but the subspecies is known to occur from central-western and southern Texas, southeastern E:\FR\FM\09AUP1.SGM 09AUP1 mstockstill on DSK4VPTVN1PROD with PROPOSALS Federal Register / Vol. 77, No. 154 / Thursday, August 9, 2012 / Proposed Rules Colorado, southern New Mexico, southeastern Arizona, and northern Mexico (Conant and Collins 1991, map 193; Werler and Dixon 2000, pp. 402– 403). Historically, the snakes may have occurred in far western Oklahoma and extreme southwestern Kansas contiguous with the range in Colorado, but their present occurrence in both States is unknown (Mackessy 2005, p. 10). Anderson et al. (2009, pp. 740–741) provide the most recent description of the range as a series of isolated populations, rather than a continuous distribution. The desert massasauga in southeastern Colorado is especially disjunct from the rest of the range of the subspecies. The taxonomic relationship of this population to the rest of the other massasauga subspecies was uncertain (Maslin 1965, p. 34) until more analysis by Hobert in 1997 (as cited in Hobert et al. 2004, p. 322) placed them as the desert massasauga subspecies. The range of the subspecies in Texas occurs in disjunct populations in far south Texas, including portions of the Gulf Coast, and western and central Texas, east of the Brazos River, where it adjoins the range of the western massasauga (Werler and Dixon 2000, pp. 402–403). However, the distribution map by Anderson et al. (2009, p. 741) shows a larger separation between the two subspecies in Texas. In New Mexico, it occurs in the southeastern part of the State contiguous with western Texas and then in isolated populations in the middle and lower Rio Grande Valley across south-central New Mexico (Anderson et al. 2009, pp. 740–741). In Arizona, it occurs in the extreme southeastern part of the State (Anderson et al. 2009, pp. 740–741). Only two small disjunct populations are known from Mexico, but extensive searches there have not been conducted (Ernst and Ernst 2003, p. 553). Mackessy (2005, pp. 12, 15) hypothesized that the historic range was likely continuous from southeastern Colorado to northern Mexico but has been fragmented due to climatic changes effecting the distribution of the shortgrass prairie of the Great Plains and human-caused factors that resulted in habitat loss. The current patchy distribution has been hypothesized as a consequence of both narrow ecological tolerances and Holocene (about 12,000 years before present) climate changes (becoming drier) that have fragmented suitable habitat (Greene 1997 in Anderson et al. 2009, p. 740). Across the range, population sizes and trends for the desert massasauga are largely unknown due to the paucity of data collection and analysis. However, VerDate Mar<15>2010 16:15 Aug 08, 2012 Jkt 226001 numerous herpetologists have made general assessments on the status of the subspecies. For example, Werler and Dixon (2000, p. 406) state that continued alteration of the massasauga’s open habitat for farmland and suburban housing development has caused a significant decline in the snake’s numbers. In 2001, the Arizona Game and Fish Department (2001, p. 3) reported that, while quantified data are lacking, the desert massasauga has almost certainly experienced long-term population declines and a general range contraction in Arizona. The populations in southeastern Colorado are exceptions, and long-term research there has indicated that local populations in some parts of the State are ‘‘reasonably robust and stable’’ due to intact habitat conditions (Mackessy 2005, p. 12). Evaluation of Information for This Finding Section 4 of the Act (16 U.S.C. 1533) and its implementing regulations at 50 CFR 424 set forth the procedures for adding a species to, or removing a species from, the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) Overutilization for commercial, recreational, scientific, or educational purposes; (C) Disease or predation; (D) The inadequacy of existing regulatory mechanisms; or (E) Other natural or manmade factors affecting its continued existence. In considering what factors might constitute threats, we must look beyond the mere exposure of the species to the factor to determine whether the species responds to the factor in a way that causes actual impacts to the species. If there is exposure to a factor, but no response, or only a positive response, that factor is not a threat. If there is exposure and the species responds negatively, the factor may be a threat and we then attempt to determine how significant a threat it is. If the threat is significant, it may drive or contribute to the risk of extinction of the species such that the species may warrant listing as endangered or threatened as those terms are defined by the Act. This does not necessarily require empirical proof of a threat. The combination of exposure and some corroborating evidence of how the species is likely impacted could suffice. The mere identification of factors that PO 00000 Frm 00028 Fmt 4702 Sfmt 4702 47585 could impact a species negatively may not be sufficient to compel a finding that listing may be warranted. The information must contain evidence sufficient to suggest that these factors may be operative threats that act on the species to the point that the species may meet the definition of endangered or threatened under the Act. In making this 90-day finding, we evaluated whether information regarding the status and threats to the desert massasauga, as presented in the petition and other information readily available in our files, is substantial, thereby indicating that the petitioned action may be warranted. Our evaluation of this information is presented below. Evaluation of Petition Information and Finding for Desert Massasauga The petition presented information regarding the following factors as potential threats to the desert massasauga: Conversion of native grasslands to crops, heavy livestock grazing, urbanization, energy development, desertification, water diversion and depletion, loss of rodent prey base, proliferation of noxious weeds, direct killing, collection for the pet trade, predation from natural predators, paramyxovirus (disease), inadequacy of existing regulatory mechanisms, death from vehicle strikes, natural vulnerability (low fecundity, low survivorship, and short lifespan), fragmentation and isolation, human population growth, drought and climate change, and the cumulative impact of these threats. After reviewing the information provided in the petition and information available in our files, we have determined that there is substantial information to indicate the desert massasauga may warrant listing as a result of habitat degradation (from land conversion to cultivated croplands and heavy livestock grazing) and death from vehicular strikes. Habitat Degradation and Loss The petition states that habitat degradation and loss are primary threats to the desert massasauga and cites a number of sources to support this position. The specific causes of habitat degradation and loss cited in the petition include conversion to crops, heavy livestock grazing, urbanization, energy development, desertification, water diversion and depletion, loss of the rodent prey base, and proliferation of noxious weeds. Our review of the petition and information in our files found substantial information that significant habitat degradation and loss may be occurring as a result of E:\FR\FM\09AUP1.SGM 09AUP1 mstockstill on DSK4VPTVN1PROD with PROPOSALS 47586 Federal Register / Vol. 77, No. 154 / Thursday, August 9, 2012 / Proposed Rules agricultural land use (conversion of native grasslands to crops) and heavy livestock grazing. In support of conversion to crops as a source of habitat loss to the species, the petition cites Mackessy (2005, p. 24), who reports that the conversion of grassland to farmland is a concern to the subspecies in southeastern Colorado. When native shortgrass prairie is converted to cultivated agricultural fields, the habitat for the desert massasauga is directly and completely lost. The snake is not able to complete its life-history needs in cultivated fields due to absence of shelter, prey, and hibernation sites, resulting in a loss of individuals of the subspecies and decline in the size of local populations (Mackessy 2005, p. 42). In addition to direct habitat loss, farmland also fragments the remaining native habitats and may impact the subspecies by isolating populations from one another. This population isolation may put populations at greater risk of loss by resulting in lower population sizes (which are more vulnerable to stochastic events), as well asthe prevention of the exchange of genetic material between populations. The petition does not provide any information on the geographic extent of crop conversion across the snake’s range outside of Colorado. However, the effects of crop conversion has occurred to at least some extent in other parts of the range, because Anderson et al. (2009, p. 740) cites encroachment of agriculture as one of the significant causes of decline and extirpation of desert massasauga populations. In support of heavy livestock grazing as a source of habitat loss, the petition cites several sources. Mackessy (2005, p. 24) explains that livestock per se are compatible with the conservation of the desert massasauga; however, if overgrazing results in severe degradation of the native shortgrass prairie in Colorado, then habitats will be altered and the desert massasauga will not be able to inhabit these areas. Mackessy (2005, p. 47) also states that properly managed grazing can be compatible with desert massasauga, but overgrazing can severely degrade habitat. Zwartjes et al. (2005, p. 22) also reports that desert massasauga are grassland specialists that respond negatively to degradation of pure grasslands by invasive shrub encroachment, which can result from landscape changes due to improper grazing management. They concluded that conversion of grasslands to scrublands in the Southwest (Arizona and New Mexico) have severe negative effects on most populations of desert VerDate Mar<15>2010 16:15 Aug 08, 2012 Jkt 226001 massasauga due to a loss of protective cover (Zwartjes et al. 2005, p. 22). Ernst and Ernst (2003, p. 557) state that the loss of grasslands in the Southwest due to overgrazing has eliminated much of the snake’s original habitat. While the petition does not provide specific information on the geographic extent of the concerns for overgrazing, most of the snake’s range is used for livestock grazing, which has been a long-time concern for land management and conservation of wildlife in the Southwest (Zwartjes et al. 2005, p. 22). Mortality From Vehicular Strikes The petition explains that one indirect consequence of any land development, whether for urbanization, agriculture, or energy, is the building and maintenance of roadways across the habitat of the desert massasauga. During active periods for migration and movement in the spring and fall, snakes will cross roadways and at other times will also use roads as basking sites in the evening for the residual warmth provided by the road (Mackessy 2005, p. 41). As a result, vehicle strikes of snakes on roads have been cited by researchers as a significant source of mortality for the desert massasauga (Werler and Dixon 2000, p. 403; Anderson et al. 2009, p. 740). In one intensive study in Arizona, 47.5 percent of all desert massasaugas encountered along one stretch of roadway (out of a total of 99 encounters) were found dead due to vehicle strikes (Holycross and Douglas 1996, p. 10). During one week in May 2005, a Colorado landowner collected 15 dead desert massasaugas along a 1.6km (1-mi) stretch of a remote, rarely traveled gravel road (Mackessy 2005, p. 46). Mackessy (2005, p. 46) observed that the strikes not only occurred accidentally but also intentionally, as drivers sought to run over rattlesnakes observed in the road. In reviewing the natural predators of desert massasaugas, Ernst and Ernst (2003, p. 556) concluded, ‘‘* * * humans (through habitat destruction and roadkills) probably eliminate more massasaugas each year than all natural predators combined.’’ We are not aware of any quantitative studies analyzing the population-level effects caused by the loss of individuals from vehicular strikes across the subspecies’ range. Roadways occur throughout the subspecies’ range, and future development will bring more roads into habitats of the desert massasauga. In areas where roadways are dense or where roads exist in high-quality desert massasauga habitats, vehicular strikes may have significant negative effects on the subspecies due to high levels of PO 00000 Frm 00029 Fmt 4702 Sfmt 4702 mortality reducing the number of adult snakes in local populations resulting in potential population-level effects to the subspecies. Finding The information presented in the petition indicates that the desert massasauga is subject to negative effects resulting from habitat degradation (from land conversion to cultivated croplands and heavy livestock grazing) and vehicular strikes. In addition, information is presented that indicates the subspecies may have undergone some range reduction over time and may be experiencing population declines in some portions of its range. This information is sufficient to suggest that these factors may be operative threats that act on the subspecies to the point that it may meet the definition of endangered or threatened under the Act. Therefore, on the basis of our determination under section 4(b)(3)(A) of the Act, we find that the petition presents substantial scientific or commercial information indicating that listing the desert massasauga throughout its entire range may be warranted. Because we have found that the petition presents substantial information indicating that listing the desert massasauga may be warranted, we will initiate a status review to determine whether listing the desert massasauga under the Act is warranted. If necessary, we will also evaluate during the status review whether a distinct population segment of desert massasauga in Colorado, Kansas, and Oklahoma warrants listing. This finding was made primarily based on the information related to habitat degradation (from land conversion to cultivated croplands and heavy livestock grazing) and vehicular strikes. We will evaluate all information under the five factors during the status review under section 4(b)(3)(B) of the Act. As noted above, the petition also presented information that there may be other potential threats to the desert massasauga. We will fully evaluate these potential threats during our status review, pursuant to the Act’s requirement to review the best available scientific information when making that finding. Accordingly, we encourage the public to consider and submit information related to these and any other threats that may be operating on the desert massasauga (see ‘‘Request for Information’’). References Cited A complete list of references cited is available on the Internet at https:// www.regulations.gov and upon request E:\FR\FM\09AUP1.SGM 09AUP1 Federal Register / Vol. 77, No. 154 / Thursday, August 9, 2012 / Proposed Rules from the Southwest Regional Office (see FOR FURTHER INFORMATION CONTACT). Authors The primary authors of this notice are the staff members of the Southwest Regional Office (see FOR FURTHER INFORMATION CONTACT). Authority: The authority for this action is the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.). Dated: July 26, 2012. Thomas O. Melius, Acting Director, U.S. Fish and Wildlife Service. [FR Doc. 2012–19476 Filed 8–8–12; 8:45 am] BILLING CODE 4310–55–P DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS–R1–ES–2011–0098; 4500030113] RIN 1018–AX14 Endangered and Threatened Wildlife and Plants; Listing 38 Species on Molokai, Lanai, and Maui as Endangered and Designating Critical Habitat on Molokai, Lanai, Maui, and Kahoolawe for 135 Species AGENCY: Background Fish and Wildlife Service, Interior. Proposed rule; extension of comment period. ACTION: We, the U.S. Fish and Wildlife Service (Service), are extending the comment period on our proposed rule to, among other things, list 38 species on the Hawaiian Islands of Molokai, Lanai, and Maui as endangered species under the Endangered Species Act of 1973, as amended, and designate critical habitat on Molokai, Lanai, Maui, and Kahoolawe for 135 species. We made the proposed rule available for public comment on June 11, 2012. DATES: The comment period end date is September 10, 2012. The deadline for submitting an electronic comment using the Federal eRulemaking Portal (see ADDRESSES section, below) is 11:59 p.m. Eastern Time on this date. After September 10, 2012, you must submit information directly to the Division of Policy and Directives Management (see ADDRESSES section below). Please note that we might not be able to address or incorporate information that we receive after the above requested date. ADDRESSES: You may submit information by one of the following methods: mstockstill on DSK4VPTVN1PROD with PROPOSALS SUMMARY: VerDate Mar<15>2010 16:15 Aug 08, 2012 Jkt 226001 (1) Electronically: Go to the Federal eRulemaking Portal: https:// www.regulations.gov. In the Search box, enter FWS–R1–ES–2011–0098, which is the docket number for this action. Then click on the Search button. You may submit a comment by clicking on ‘‘Comment Now!’’ (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS–R1–ES–2011– 0098; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042–PDM; Arlington, VA 22203. We will post all information we receive on https://www.regulations.gov. This generally means that we will post any personal information you provide us (see the Request for Information section below for more details). FOR FURTHER INFORMATION CONTACT: Loyal Mehrhoff, Field Supervisor, Pacific Islands Fish and Wildlife Office, 300 Ala Moana Boulevard, Box 50088, Honolulu, HI 96850; by telephone at 808–792–9400; or by facsimile at 808– 792–9581. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800–877–8339. SUPPLEMENTARY INFORMATION: On June 11, 2012 (77 FR 34464), we published in the Federal Register, for review and comment, a proposed rule to list 38 species (35 plants and 3 tree snails) on the Hawaiian Islands of Molokai, Lanai, and Maui as endangered species, and concurrent designation of 271,062 acres (ac) (109,695 hectares (ha)) as critical habitat. We are also proposing revision of critical habitat for 85 plants and designation of critical habitat for 11 listed plants and animals that do not have designated critical habitat on these islands. Approximately 47 percent of the area being proposed as critical habitat is already designated as critical habitat for the 85 plant species or for other species. We also propose to delist the plant Gahnia lanaiensis, due to new information that this species is synonymous with G. lacera, a widespread species from New Zealand. In addition, we propose name changes or corrections for 11 endangered plants and 2 endangered birds, and we propose to reaffirm the listings for 2 endangered plant species with taxonomic revisions. We are also considering excluding approximately 40,973 ac (16,581 ha) of privately owned lands on Maui and Molokai. We received a request to extend the public comment period beyond the August 10, 2012, due date on our June PO 00000 Frm 00030 Fmt 4702 Sfmt 4702 47587 11, 2012 (77 FR 34464), proposal. We are working with our partners and local landowners to inform them of the proposed listings and critical habitat designations. In order to ensure that the public has an adequate opportunity to review and comment on our proposed rule, we are extending the comment period for an additional 30 days. Request for Information We will accept written comments and information during this extended comment period. We will consider information and recommendations from all interested parties and intend that any final action resulting from this proposal will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we solicit comments or suggestions on this proposed rule from the public, other concerned governmental agencies, the scientific community, industry, or other interested parties. We particularly seek comments concerning: (1) Biological, commercial trade, or other relevant data concerning threats (or the lack thereof) to the 40 species proposed or being reevaluated for listing, and regulations that may be addressing those threats. (2) Additional information concerning the range, distribution, and population sizes of each of the 40 species proposed or being reevaluated for listing, including the locations of any additional populations of these species. (3) Any information on the biological or ecological requirements of the 40 species proposed or being reevaluated for listing. (4) The reasons why we should or should not designate areas for any of the species in this proposal as ‘‘critical habitat’’ under section 4 of the Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.), including whether there are threats to these species from human activity, the degree to which can be expected to increase due to the designation, and whether the benefit of designation would outweigh threats to these species caused by the designation, such that the designation of critical habitat is prudent. (5) Whether a revision of critical habitat is warranted for the 85 plant species that are already listed as endangered or threatened under the Act and that currently have designated critical habitat. (6) Specific information on: • The amount and distribution of critical habitat for the species included in this proposed rule; E:\FR\FM\09AUP1.SGM 09AUP1

Agencies

[Federal Register Volume 77, Number 154 (Thursday, August 9, 2012)]
[Proposed Rules]
[Pages 47583-47587]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-19476]

[[Page 47583]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2012-0057; 4500030114]

Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition To List Desert Massasauga as Endangered or Threatened and To
Designate Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of petition finding and initiation of status review.

-----------------------------------------------------------------------

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding on a petition to list desert massasauga (Sistrurus
catenatus edwardsii), a rattlesnake found in the southwestern United
States, as endangered or threatened under the Endangered Species Act of
1973, as amended (Act), and to designate critical habitat. Based on our
review, we find that the petition presents substantial scientific or
commercial information indicating that listing desert massasauga may be
warranted. We will initiate a review of the status of this subspecies
to determine if listing is warranted. We are requesting scientific and
commercial data and other information regarding this subspecies. Based
on the status review, we will issue a 12-month finding on the petition,
which will address whether the petitioned action is warranted as
provided in section 4(b)(3)(B) of the Act.

DATES: We request that we receive information on or before October 9,
2012. The deadline for submitting an electronic comment using the
Federal eRulemaking Portal (see ADDRESSES section, below) is 11:59 p.m.
Eastern Time on this date. After October 9, 2012, you must submit
information directly to the Division of Policy and Directives
Management (see ADDRESSES section, below). Please note that we might
not be able to address or incorporate information that we receive after
the above requested date.

ADDRESSES: You may submit information by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. Search for Docket No. FWS-R2-ES-2012-0057.
(2) By hard copy: Submit by U.S. mail or hand-delivery to: Public
Comments Processing, Attn: FWS-R2-ES-2012-0057; Division of Policy and
Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax
Drive, MS 2042-PDM; Arlington, VA 22203.
We will not accept emails or faxes. We will post all information we
receive on https://www.regulations.gov. This generally means that we
will post any personal information you provide us (see the Request for
Information section below for more details).

FOR FURTHER INFORMATION CONTACT: Michelle Shaughnessy, Assistant
Regional Director, Southwest Regional Office, 500 Gold Ave. SW., Room
6034, Albuquerque, NM 87102; by telephone at 505-248-6920; or by
facsimile at 505-248-6788. If you use a telecommunications device for
the deaf (TDD), please call the Federal Information Relay Service
(FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Request for Information

When we make a finding that a petition presents substantial
information indicating that listing a species may be warranted, we are
required to promptly review the status of the species (status review).
For the status review to be complete and based on the best available
scientific and commercial information, we request information on desert
massasauga from governmental agencies, Native American tribes, the
scientific community, industry, and any other interested parties. We
seek information on:
(1) The subspecies' biology, range, and population trends,
including:
(a) Habitat requirements for reproduction, germination, and
survival;
(b) Genetics and taxonomy;
(c) Historical and current range, including distribution patterns;
(d) Historical and current population levels, and current and
projected trends; and
(e) Past and ongoing conservation measures for the species, its
habitat, or both.
(2) The factors that are the basis for making a listing, delisting,
or downlisting determination for a species under section 4(a) of the
Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et
seq.), which are:
(a) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(b) Overutilization for commercial, recreational, scientific, or
educational purposes;
(c) Disease or predation;
(d) The inadequacy of existing regulatory mechanisms; or
(e) Other natural or manmade factors affecting its continued
existence.
If, after the status review, we determine that listing desert
massasauga is warranted, we will propose critical habitat (see
definition in section 3(5)(A) of the Act), under section 4 of the Act,
to the maximum extent prudent and determinable at the time we propose
to list the species. Therefore, we request data and information on:
(1) What may constitute ``physical or biological features essential
to the conservation of the species'' within the geographical range
currently occupied by the subspecies;
(2) Where these features are currently found;
(3) Whether any of these features may require special management
considerations or protection;
(4) Specific areas outside the geographical area occupied by the
subspecies that are ``essential for the conservation of the species;''
and
(5) What, if any, critical habitat you think we should propose for
designation if the subspecies is proposed for listing, and why such
habitat meets the requirements of section 4 of the Act.
Please include sufficient information with your submission (such as
scientific journal articles or other publications) to allow us to
verify any scientific or commercial information you include.
Submissions merely stating support for or opposition to the action
under consideration without providing supporting information, although
noted, will not be considered in making a determination. Section
4(b)(1)(A) of the Act directs that determinations as to whether any
species is an endangered or threatened species must be made ``solely on
the basis of the best scientific and commercial data available.''
You may submit your information concerning this status review by
one of the methods listed in the ADDRESSES section. If you submit
information via https://www.regulations.gov, your entire submission--
including any personal identifying information--will be posted on the
Web site. If you submit a hardcopy that includes personal identifying
information, you may request at the top of your document that we
withhold this personal identifying information from public review.
However, we cannot guarantee that we will be able to do so. We will
post all hardcopy submissions on https://www.regulations.gov.
Information and supporting documentation that we received and used
in preparing this finding are available for you to review at https://www.regulations.gov, or you may make an appointment during normal
business hours at the U.S. Fish and Wildlife

[[Page 47584]]

Service, Southwest Regional Office (see FOR FURTHER INFORMATION
CONTACT).

Background

Section 4(b)(3)(A) of the Act requires that we make a finding on
whether a petition to list, delist, or reclassify a species presents
substantial scientific or commercial information indicating that the
petitioned action may be warranted. We are to base this finding on
information provided in the petition, supporting information submitted
with the petition, and information otherwise available in our files. To
the maximum extent practicable, we are to make this finding within 90
days of our receipt of the petition and publish our notice of the
finding promptly in the Federal Register.
Our standard for substantial scientific or commercial information
within the Code of Federal Regulations (CFR) with regard to a 90-day
petition finding is ``that amount of information that would lead a
reasonable person to believe that the measure proposed in the petition
may be warranted'' (50 CFR 424.14(b)). If we find that substantial
scientific or commercial information was presented, we are required to
promptly conduct a species status review, which we subsequently
summarize in our 12-month finding.
The ``substantial information'' standard for a 90-day finding
differs from the Act's ``best scientific and commercial data'' standard
that applies to a status review to determine whether a petitioned
action is warranted. A 90-day finding does not constitute a status
review under the Act. In a 12-month finding, we will announce our
determination as to whether a petitioned action is warranted after we
have completed a thorough status review of the species, which is
conducted following a substantial 90-day finding. Because the Act's
standards for 90-day findings and status reviews conducted for a 12-
month finding on a petition are different, as described above, a
substantial 90-day finding does not mean that our status review and
resulting determination will result in a warranted finding.

Petition History

On November 1, 2010, we received a petition dated October 28, 2010,
from the WildEarth Guardians, requesting that desert massasauga be
listed as endangered or threatened and critical habitat be designated
under the Act. Alternatively, the petitioner requested listing of a
distinct population segment of desert massasauga in Colorado, Kansas,
and Oklahoma. The petition clearly identified itself as such and
included the requisite identification information for the petitioner,
as required by 50 CFR 424.14(a). In a December 1, 2011, letter to the
WildEarth Guardians, we responded that we reviewed the information
presented in the petition and determined that issuing an emergency
regulation temporarily listing the subspecies under section 4(b)(7) of
the Act was not warranted. We also stated that we intended to complete
an initial finding in Fiscal Year 2012 as to whether this petition
contains substantial information indicating that the action may be
warranted. This 90-day finding addresses the October 28, 2010,
petition.

Species Information

Taxonomy and Description
The desert massasauga (Sistrurus catenatus edwardsii) is a
rattlesnake (Family Viperidae) classified as a subspecies of massasauga
(Sistrurus catenatus) (Conant and Collins 1991, p. 232; Ernst and Ernst
2003, pp. 552-553; Collins and Taggart 2009, p. 32). As a widely
recognized subspecies, it is a listable entity under the Act.
Mackessy (2005, p. 10) described the color of desert massasauga as
gray to light brown, with 37 to 40 darker brown saddles or semicircular
blotches, outlined in black, forming a regular pattern on the dorsal
surface. A prominent dark brown to black stripe extends from the eye to
the angle of the jaw, and a lyre-shaped or paired irregular set of
stripes extends from the dorsal surface of the head to the first body
blotch. The base of the rattle on the tail is typically black, but in
neonates (young snakes), the tip is yellow. The desert massasauga is
relatively small compared to other rattlesnakes, reaching a maximum
adult total length of 588 millimeters (mm) (23 inches (in)) (Holycross
2001, p. 59), with an average length of about 380 mm (15 in) (Mackessy
2005, p. 27).
The desert massasauga is venomous, and the venom is used to acquire
prey and is toxic to humans. However, due to its small adult size,
venom yields are low, and bites to humans, although potentially
serious, are not likely to be life-threatening (Mackessy 2005, p. 10).
The probability of a desert massasauga biting a human is also very low
because there is only a small chance of encountering the snake due to
its nocturnality; spotty distribution; and generally cryptic, elusive,
and nonaggressive behavior (Werler and Dixon 2000, p. 404).
Habitat
The desert massasauga occurs in a variety of grassland and
shrubland habitats, including shortgrass prairie, sandsage grasslands,
shinnery oak, Chihuahuan desert, and occasionally sand dune habitat
(Degenhardt et al. 1996, p. 356; Hobert et al. 2004, p. 323; Mackessy
2007, p. 2). Studies in Colorado have shown it inhabits primarily
shortgrass prairie habitat with Artemisia filifolia (sand sage),
Buchloe dactyloides (buffalograss), and Bouteloua gracilis (blue grama)
below about 1,500 meters (5,000 feet) in elevation. Although the
species is adapted to xeric (dry) conditions, the subspecies is most
abundant in areas of prairie with more mesic (moist) conditions
(Mackessy 2005, p. 23). The snake uses grasses for capturing prey and
avoiding predators, as these areas provide protective cover. The
subspecies is not often found in scrub or shrub habitats in most parts
of its range.
Life History
The biology of the desert massasauga has been studied in some
detail in some parts of its range. The snakes hibernate from October to
mid-April in Colorado (Hobert et al. 2004, p. 324), and from November
to March in New Mexico (Degenhardt et al. 1996, p. 357) with presumably
similar timeframes of hibernation in other parts of its range. They
commonly use rodent burrows for hibernation and as birthing sites
(Mackessy 2005, pp. 16-17, 23; Mackessy 2007, p. 8). They are mainly
nocturnal and may migrate up to 2 kilometers (km) (1.2 miles (mi))
seasonally between locations used for winter hibernation and those used
during active periods (Ernst and Ernst 2003, p. 554; Mackessy 2005, pp.
20-21). Desert massasauga feed on a wide variety of prey, including
lizards, small mammals, and centipedes (Holycross and Mackessy 2002, p.
456). Females have been observed to give birth in the summer to between
4 and 8 young (Hobert et al. 2004, pp. 324-325; Mackessy 2005, p. 29),
and may not reproduce every year (Goldberg and Holycross 1999, p. 531).
Most adults collected in the field were estimated to be 4 years old or
less, though members of the subspecies have lived more than 14 years in
captivity.
Distribution and Abundance
The range of desert massasauga is reported with some variation in
published accounts, but the subspecies is known to occur from central-
western and southern Texas, southeastern

[[Page 47585]]

Colorado, southern New Mexico, southeastern Arizona, and northern
Mexico (Conant and Collins 1991, map 193; Werler and Dixon 2000, pp.
402-403). Historically, the snakes may have occurred in far western
Oklahoma and extreme southwestern Kansas contiguous with the range in
Colorado, but their present occurrence in both States is unknown
(Mackessy 2005, p. 10). Anderson et al. (2009, pp. 740-741) provide the
most recent description of the range as a series of isolated
populations, rather than a continuous distribution.
The desert massasauga in southeastern Colorado is especially
disjunct from the rest of the range of the subspecies. The taxonomic
relationship of this population to the rest of the other massasauga
subspecies was uncertain (Maslin 1965, p. 34) until more analysis by
Hobert in 1997 (as cited in Hobert et al. 2004, p. 322) placed them as
the desert massasauga subspecies. The range of the subspecies in Texas
occurs in disjunct populations in far south Texas, including portions
of the Gulf Coast, and western and central Texas, east of the Brazos
River, where it adjoins the range of the western massasauga (Werler and
Dixon 2000, pp. 402-403). However, the distribution map by Anderson et
al. (2009, p. 741) shows a larger separation between the two subspecies
in Texas. In New Mexico, it occurs in the southeastern part of the
State contiguous with western Texas and then in isolated populations in
the middle and lower Rio Grande Valley across south-central New Mexico
(Anderson et al. 2009, pp. 740-741). In Arizona, it occurs in the
extreme southeastern part of the State (Anderson et al. 2009, pp. 740-
741). Only two small disjunct populations are known from Mexico, but
extensive searches there have not been conducted (Ernst and Ernst 2003,
p. 553). Mackessy (2005, pp. 12, 15) hypothesized that the historic
range was likely continuous from southeastern Colorado to northern
Mexico but has been fragmented due to climatic changes effecting the
distribution of the shortgrass prairie of the Great Plains and human-
caused factors that resulted in habitat loss. The current patchy
distribution has been hypothesized as a consequence of both narrow
ecological tolerances and Holocene (about 12,000 years before present)
climate changes (becoming drier) that have fragmented suitable habitat
(Greene 1997 in Anderson et al. 2009, p. 740).
Across the range, population sizes and trends for the desert
massasauga are largely unknown due to the paucity of data collection
and analysis. However, numerous herpetologists have made general
assessments on the status of the subspecies. For example, Werler and
Dixon (2000, p. 406) state that continued alteration of the
massasauga's open habitat for farmland and suburban housing development
has caused a significant decline in the snake's numbers. In 2001, the
Arizona Game and Fish Department (2001, p. 3) reported that, while
quantified data are lacking, the desert massasauga has almost certainly
experienced long-term population declines and a general range
contraction in Arizona. The populations in southeastern Colorado are
exceptions, and long-term research there has indicated that local
populations in some parts of the State are ``reasonably robust and
stable'' due to intact habitat conditions (Mackessy 2005, p. 12).

Evaluation of Information for This Finding

Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations at 50 CFR 424 set forth the procedures for adding a species
to, or removing a species from, the Federal Lists of Endangered and
Threatened Wildlife and Plants. A species may be determined to be an
endangered or threatened species due to one or more of the five factors
described in section 4(a)(1) of the Act:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
In considering what factors might constitute threats, we must look
beyond the mere exposure of the species to the factor to determine
whether the species responds to the factor in a way that causes actual
impacts to the species. If there is exposure to a factor, but no
response, or only a positive response, that factor is not a threat. If
there is exposure and the species responds negatively, the factor may
be a threat and we then attempt to determine how significant a threat
it is. If the threat is significant, it may drive or contribute to the
risk of extinction of the species such that the species may warrant
listing as endangered or threatened as those terms are defined by the
Act. This does not necessarily require empirical proof of a threat. The
combination of exposure and some corroborating evidence of how the
species is likely impacted could suffice. The mere identification of
factors that could impact a species negatively may not be sufficient to
compel a finding that listing may be warranted. The information must
contain evidence sufficient to suggest that these factors may be
operative threats that act on the species to the point that the species
may meet the definition of endangered or threatened under the Act.
In making this 90-day finding, we evaluated whether information
regarding the status and threats to the desert massasauga, as presented
in the petition and other information readily available in our files,
is substantial, thereby indicating that the petitioned action may be
warranted. Our evaluation of this information is presented below.

Evaluation of Petition Information and Finding for Desert Massasauga

The petition presented information regarding the following factors
as potential threats to the desert massasauga: Conversion of native
grasslands to crops, heavy livestock grazing, urbanization, energy
development, desertification, water diversion and depletion, loss of
rodent prey base, proliferation of noxious weeds, direct killing,
collection for the pet trade, predation from natural predators,
paramyxovirus (disease), inadequacy of existing regulatory mechanisms,
death from vehicle strikes, natural vulnerability (low fecundity, low
survivorship, and short lifespan), fragmentation and isolation, human
population growth, drought and climate change, and the cumulative
impact of these threats. After reviewing the information provided in
the petition and information available in our files, we have determined
that there is substantial information to indicate the desert massasauga
may warrant listing as a result of habitat degradation (from land
conversion to cultivated croplands and heavy livestock grazing) and
death from vehicular strikes.
Habitat Degradation and Loss
The petition states that habitat degradation and loss are primary
threats to the desert massasauga and cites a number of sources to
support this position. The specific causes of habitat degradation and
loss cited in the petition include conversion to crops, heavy livestock
grazing, urbanization, energy development, desertification, water
diversion and depletion, loss of the rodent prey base, and
proliferation of noxious weeds. Our review of the petition and
information in our files found substantial information that significant
habitat degradation and loss may be occurring as a result of

[[Page 47586]]

agricultural land use (conversion of native grasslands to crops) and
heavy livestock grazing.
In support of conversion to crops as a source of habitat loss to
the species, the petition cites Mackessy (2005, p. 24), who reports
that the conversion of grassland to farmland is a concern to the
subspecies in southeastern Colorado. When native shortgrass prairie is
converted to cultivated agricultural fields, the habitat for the desert
massasauga is directly and completely lost. The snake is not able to
complete its life-history needs in cultivated fields due to absence of
shelter, prey, and hibernation sites, resulting in a loss of
individuals of the subspecies and decline in the size of local
populations (Mackessy 2005, p. 42). In addition to direct habitat loss,
farmland also fragments the remaining native habitats and may impact
the subspecies by isolating populations from one another. This
population isolation may put populations at greater risk of loss by
resulting in lower population sizes (which are more vulnerable to
stochastic events), as well asthe prevention of the exchange of genetic
material between populations. The petition does not provide any
information on the geographic extent of crop conversion across the
snake's range outside of Colorado. However, the effects of crop
conversion has occurred to at least some extent in other parts of the
range, because Anderson et al. (2009, p. 740) cites encroachment of
agriculture as one of the significant causes of decline and extirpation
of desert massasauga populations.
In support of heavy livestock grazing as a source of habitat loss,
the petition cites several sources. Mackessy (2005, p. 24) explains
that livestock per se are compatible with the conservation of the
desert massasauga; however, if overgrazing results in severe
degradation of the native shortgrass prairie in Colorado, then habitats
will be altered and the desert massasauga will not be able to inhabit
these areas. Mackessy (2005, p. 47) also states that properly managed
grazing can be compatible with desert massasauga, but overgrazing can
severely degrade habitat. Zwartjes et al. (2005, p. 22) also reports
that desert massasauga are grassland specialists that respond
negatively to degradation of pure grasslands by invasive shrub
encroachment, which can result from landscape changes due to improper
grazing management. They concluded that conversion of grasslands to
scrublands in the Southwest (Arizona and New Mexico) have severe
negative effects on most populations of desert massasauga due to a loss
of protective cover (Zwartjes et al. 2005, p. 22). Ernst and Ernst
(2003, p. 557) state that the loss of grasslands in the Southwest due
to overgrazing has eliminated much of the snake's original habitat.
While the petition does not provide specific information on the
geographic extent of the concerns for overgrazing, most of the snake's
range is used for livestock grazing, which has been a long-time concern
for land management and conservation of wildlife in the Southwest
(Zwartjes et al. 2005, p. 22).
Mortality From Vehicular Strikes
The petition explains that one indirect consequence of any land
development, whether for urbanization, agriculture, or energy, is the
building and maintenance of roadways across the habitat of the desert
massasauga. During active periods for migration and movement in the
spring and fall, snakes will cross roadways and at other times will
also use roads as basking sites in the evening for the residual warmth
provided by the road (Mackessy 2005, p. 41). As a result, vehicle
strikes of snakes on roads have been cited by researchers as a
significant source of mortality for the desert massasauga (Werler and
Dixon 2000, p. 403; Anderson et al. 2009, p. 740). In one intensive
study in Arizona, 47.5 percent of all desert massasaugas encountered
along one stretch of roadway (out of a total of 99 encounters) were
found dead due to vehicle strikes (Holycross and Douglas 1996, p. 10).
During one week in May 2005, a Colorado landowner collected 15 dead
desert massasaugas along a 1.6-km (1-mi) stretch of a remote, rarely
traveled gravel road (Mackessy 2005, p. 46). Mackessy (2005, p. 46)
observed that the strikes not only occurred accidentally but also
intentionally, as drivers sought to run over rattlesnakes observed in
the road. In reviewing the natural predators of desert massasaugas,
Ernst and Ernst (2003, p. 556) concluded, ``* * * humans (through
habitat destruction and roadkills) probably eliminate more massasaugas
each year than all natural predators combined.'' We are not aware of
any quantitative studies analyzing the population-level effects caused
by the loss of individuals from vehicular strikes across the
subspecies' range. Roadways occur throughout the subspecies' range, and
future development will bring more roads into habitats of the desert
massasauga. In areas where roadways are dense or where roads exist in
high-quality desert massasauga habitats, vehicular strikes may have
significant negative effects on the subspecies due to high levels of
mortality reducing the number of adult snakes in local populations
resulting in potential population-level effects to the subspecies.

Finding

The information presented in the petition indicates that the desert
massasauga is subject to negative effects resulting from habitat
degradation (from land conversion to cultivated croplands and heavy
livestock grazing) and vehicular strikes. In addition, information is
presented that indicates the subspecies may have undergone some range
reduction over time and may be experiencing population declines in some
portions of its range. This information is sufficient to suggest that
these factors may be operative threats that act on the subspecies to
the point that it may meet the definition of endangered or threatened
under the Act. Therefore, on the basis of our determination under
section 4(b)(3)(A) of the Act, we find that the petition presents
substantial scientific or commercial information indicating that
listing the desert massasauga throughout its entire range may be
warranted. Because we have found that the petition presents substantial
information indicating that listing the desert massasauga may be
warranted, we will initiate a status review to determine whether
listing the desert massasauga under the Act is warranted. If necessary,
we will also evaluate during the status review whether a distinct
population segment of desert massasauga in Colorado, Kansas, and
Oklahoma warrants listing.
This finding was made primarily based on the information related to
habitat degradation (from land conversion to cultivated croplands and
heavy livestock grazing) and vehicular strikes. We will evaluate all
information under the five factors during the status review under
section 4(b)(3)(B) of the Act. As noted above, the petition also
presented information that there may be other potential threats to the
desert massasauga. We will fully evaluate these potential threats
during our status review, pursuant to the Act's requirement to review
the best available scientific information when making that finding.
Accordingly, we encourage the public to consider and submit information
related to these and any other threats that may be operating on the
desert massasauga (see ``Request for Information'').

References Cited

A complete list of references cited is available on the Internet at
https://www.regulations.gov and upon request

[[Page 47587]]

from the Southwest Regional Office (see FOR FURTHER INFORMATION
CONTACT).

Authors

The primary authors of this notice are the staff members of the
Southwest Regional Office (see FOR FURTHER INFORMATION CONTACT).

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

Dated: July 26, 2012.
Thomas O. Melius,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-19476 Filed 8-8-12; 8:45 am]
BILLING CODE 4310-55-P

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