44988 Federal Register / Vol. 71, No. 152 / Tuesday, August 8, 2006 / Proposed Rules

We have reviewed the petition and indicating that listing the Sand If we determine that listing the Sand literature cited in the petition and Mountain blue may be Mountain blue butterfly is warranted, it evaluated that information in relation to warranted. Therefore, with the is our intent to propose critical habitat information available to us. After this publication of this notice, we are to the maximum extent prudent and review and evaluation, we find the initiating a status review of the , determinable at the time we would petition does not present substantial and we will issue a 12-month finding to propose to list the species. Therefore, scientific information to indicate listing determine if the petitioned action is we also request data and information on the Thorne’s hairstreak butterfly may be warranted. To ensure that the status what may constitute physical or warranted at this time. Although we review of the Sand Mountain blue biological features essential to the will not be commencing a status review butterfly is comprehensive, we are conservation of the species, where these in response to this petition, we will soliciting scientific and commercial data features are currently found, whether continue to monitor potential threats regarding this species. A determination any of these areas are in need of special and ongoing management actions that on critical habitat will be made if and management, and whether there are might be important with regard to the when a listing action is initiated for this areas not containing these features, conservation of the Thorne’s hairstreak species. which of themselves, might be essential butterfly across its range. We encourage DATES: The finding announced in this to the conservation of the species. interested parties to continue to gather document was made August 8, 2006. To Please provide specific comments as to data that will assist with the be considered in the 12-month finding what, if any, critical habitat should be conservation of the subspecies. for this petition, comments and proposed for designation, if the species information should be submitted to us is proposed for listing, and why that References Cited by October 10, 2006. proposed habitat meets the A complete list of all references cited ADDRESSES: Data, information, requirements of the Act. If you wish to comment or provide herein is available, upon request, from comments, or questions concerning this information, you may submit your our Carlsbad Fish and Wildlife Office petition and our finding should be comments and materials concerning this (see ADDRESSES section above). submitted to the Field Supervisor, finding to the Field Supervisor (see Nevada Fish and Wildlife Office, U.S. Author ADDRESSES). Fish and Wildlife Service, 1340 The primary authors of this notice are Our practice is to make comments and Financial Boulevard, Suite 234, Reno, materials provided, including names staff from the Carlsbad Fish and NV 89502 or via electronic mail at Wildlife Office (see ADDRESSES section and home addresses of respondents, [email protected]. The petition is available for public review during above). available at http://www.fws.gov/nevada/ _ _ regular business hours. We will not Authority nv species/sand blue.html. The consider anonymous comments and we petition, supporting data, and comments The authority for this action is the will make all comments available for will be available for public inspection, Endangered Species Act of 1973, as public inspection in their entirety. by appointment, during normal business amended (16 U.S.C. 1531 et seq.). Comments and materials received will hours at the above address. Dated: August 1, 2006. be available for public inspection, by FOR FURTHER INFORMATION CONTACT: appointment, during normal business H. Dale Hall, Robert D. Williams, Field Supervisor, hours at the address listed in the Director, Fish and Wildlife Service. Nevada Fish and Wildlife Office (see ADDRESSES section. [FR Doc. E6–12743 Filed 8–7–06; 8:45 am] ADDRESSES) (telephone 775/861–6300; BILLING CODE 4310–55–P facsimile 775/861–6301). Background SUPPLEMENTARY INFORMATION: Section 4(b)(3)(A) of the Endangered Species Act of 1973, as amended (16 DEPARTMENT OF THE INTERIOR Public Information Solicited U.S.C. 1531 et seq.), requires that we When we make a finding that make a finding on whether a petition to Fish and Wildlife Service substantial information is presented to list, delist, or reclassify a species indicate that listing a species may be presents substantial scientific or 50 CFR Part 17 warranted, we are required to promptly commercial information to indicate that commence a review of the status of the Endangered and Threatened Wildlife the petitioned action may be warranted. species. To ensure that the status review and Plants; 90-Day Finding on a We base this finding on information is complete and based on the best Petition to List the Sand Mountain Blue provided in the petition and available scientific and commercial Butterfly as Threatened or Endangered information otherwise available in our information, we are soliciting with Critical Habitat files at the time of petition review. To information on the Sand Mountain blue the maximum extent practicable, we AGENCY: Fish and Wildlife Service, butterfly. We request any additional make this finding within 90 days of our Interior. information, comments, and suggestions receipt of the petition, and publish our ACTION: Notice of 90-day petition from the public, other concerned notice of this finding promptly in the finding and initiation of status review. governmental agencies, Tribes, the Federal Register. scientific community, industry, or any Substantial information, as defined by SUMMARY: We, the U.S. Fish and other interested parties concerning the 50 CFR 424.14(b), is ‘‘that amount of Wildlife Service (Service), announce a status of the Sand Mountain blue information that would lead a 90-day finding on a petition to list the butterfly. We are seeking information reasonable person to believe that the Sand Mountain blue butterfly regarding the species’ historical and measure proposed in the petition may ( pallescens arenamontana) current status and distribution, its be warranted’’ (50 CFR 424.14(b)). If we as threatened or endangered under the biology and ecology, ongoing find that substantial information was Endangered Species Act of 1973, as conservation measures for the species presented, we are required to promptly amended (Act). We find that the petition and its habitat, and threats to the commence a review of the status of the presents substantial information species and its habitat. species, if one has not already been

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initiated under our internal candidate (mm) (0.39 to 0.46 inches (in)) and important nectar source for adults assessment process. averages 11.1 mm (0.44 in). The dorsum during their flight period. The butterfly In making this finding, we relied on is pale bluish-violet, often whitish has one brood from mid-July to mid- information provided by the petitioners distally, with a narrow (0.5 mm (0.002 September (Austin 1998, p. 557), a and information otherwise available in in)) black outer margin. There is usually period that coincides with the peak our files at the time of petition review a series of dots on the hindwing, but flowering period of the Kearney and evaluated that information in sometimes no more than a terminal line buckwheat (Reveal 2002, p. 2). accordance with 50 CFR 424.14(b). Our on the forewing. There is usually an Previous Federal Action process in making this 90-day finding indistinct pinkish to pale orange aurora under section 4(b)(3)(A) of the Act and of moderate width on the posterior We added the Sand Mountain blue section 424.14(b) of our regulations is hindwing. At the vein tips on the butterfly as ssp. to our limited to a determination of whether posterior of both wings, there are fringes list of candidate species as a category 2 the information in the petition meets the of white with indistinct grey checkering. candidate species on November 21, ‘‘substantial information’’ threshold. The bottom surface of the male 1991 (56 FR 58829). A category 2 candidate species was a species for Petition abdomen is chalky white. Macules (patches of different coloration) are which we had information indicating On April 23, 2004, we received a small, often nearly obsolete on the that a proposal to list it as threatened or formal petition, dated April 23, 2004, hindwing. Females have a wingspan endangered under the Act may be from the Center for Biological Diversity, that ranges from 10.0 to 11.9 mm (0.39 appropriate, but for which additional Xerces Society, Public Employees for to 0.46 in) with an average of 10.9 mm information was needed to support the Environmental Responsibility, and the (0.43 in). The female dorsum is brown preparation of a proposed rule. It Nevada Outdoor Recreation Association to tan, and usually pale bluish-gray remained a category 2 candidate as requesting that the Sand Mountain blue basally on both wings. The forewing has Euphilotes rita ssp. in our 1994 butterfly ( a faint brown cell-end bar, while the Candidate Notice of Review (November arenamontana) known only from Sand hindwing has marginal dots. The 15, 1994; 59 FR 59020). In the 1996 Mountain, Nevada, be listed as forewing apex is usually whitish. The Candidate Notice of Review (February threatened or endangered in accordance hindwing aurora is pale orange to pale 28, 1996; 61 FR 7596), we discontinued with section 4 of the Act, and that pink usually grading to nearly white the use of category 2 candidates. The critical habitat be designated for the distally and not strongly contrasting. Sand Mountain blue butterfly has no species concurrent with the listing. The The female venter and fringes are Federal regulatory status under the Act. petition is available at http:// similar to those of the male (Austin Threats Analysis www.fws.gov/nevada/nv_species/ 1998, p. 556). sand_blue.html. The Sand Mountain blue butterfly is Pursuant to section 4 of the Act, we Action on this petition was precluded the palest of all Euphilotes. The ground may list a species, subspecies, or by court orders and settlement color of both sexes is considerably paler distinct population segment of agreements for other listing actions that than that of E. pallescens ssp. invertebrate taxa on the basis of any of required nearly all of our listing funds pallescens. The pinkish aurora is unlike the following five factors: (A) Present or for fiscal years 2004 and 2005. On any other Euphilotes. The pale bluish- threatened destruction, modification, or September 26, 2005, we received a 60- gray wing bases of the female do not curtailment of habitat or range; (B) day notice of intent to sue, and on contrast with the distal area of the wing overutilization for commercial, January 5, 2006, we received a as they do on E. pallescens ssp. recreational, scientific, or educational complaint regarding our failure to carry pallescens. The black macules of E. purposes; (C) disease or predation; (D) out the 90-day finding on the petition to pallescens ssp. arenamontana tend to be inadequacy of existing regulatory list the Sand Mountain blue butterfly. smaller than those of E. pallescens ssp. mechanisms; or (E) other natural or On April 20, 2006, we reached an pallescens (Austin 1998, p. 557). manmade factors affecting its continued agreement with the plaintiffs to submit The Sand Mountain blue butterfly is existence. In making this finding, we to the Federal Register a completed 90- known only from Sand Mountain, evaluated whether threats to the Sand day finding by July 28, 2006, and to Churchill County, Nevada, where it is Mountain blue butterfly presented in complete, if applicable, a 12-month dependent on its host plant, Kearney the petition may pose a concern with finding by April 26, 2007 (Center for buckwheat ( nummulare) respect to its survival. The Act identifies Biological Diversity et al. v. Norton, and (Austin 1998, p. 557), a long-lived, the five factors to be considered, either U.S. Fish and Wildlife Service, (CV– perennial shrub with numerous singly or in combination, to determine 00023–LKK–GGH) (E.D. Cal)). branches (Reveal 2002, p. 1), that occurs whether a species may be threatened or in scattered locations in several western endangered. Our evaluation of these Species Information States (Welsh et al. 1987, p. 547). threats, based on information provided The Sand Mountain blue butterfly Kearney buckwheat typically occurs at in the petition, is presented below. was first described as Euphilotes Sand Mountain as a dominant or co- pallescens subspecies arenamontana by dominant with other shrubs on less A. Present or Threatened Destruction, Austin in 1998 (1998, pp. 556–557). active, smaller dunes around the Modification, or Curtailment of the Prior to the 1998 publication, it had periphery of the main dune (The Nature Species’ Habitat or Range been considered an undescribed Conservancy 2002, p. 1). Because of the The petition states that the Sand subspecies of Euphilotes rita, the name small size of the Sand Mountain blue Mountain blue butterfly is known only under which it was previously assigned butterfly and the frequent high winds from Sand Mountain in Churchill a Federal category 2 candidate status typical of the Sand Mountain area, it is County, Nevada, where it is dependent (see Previous Federal Action section). likely that adult spend most on its larval host plant, Kearney The Sand Mountain blue butterfly is of their life sheltered within the canopy buckwheat (Eriogonum nummulare) a small, pale-blue butterfly in the family of Kearney buckwheat plants (Murphy (Austin 1998). The petitioners note that . Males have a wingspan that 2006). Kearney buckwheat is the sole while the Kearney buckwheat is ranges from 10.0 to 11.8 millimeters food source for the larvae and an widespread in Nevada and also occurs

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in Utah, Arizona, and California, several one of which is the Kearney buckwheat buckwheat in the overall area could call reconnaissance surveys have been (BLM 2004). into question the continued existence of conducted of sand dunes within 62.5 The petitioners present data in Figure the butterfly; and (4) an assessment by mile (mi) (100 kilometer (km)) radius of 9, provided to them by BLM, that The Nature Conservancy (2002) that Sand Mountain in search of populations documents an increase in annual visitor determined the condition of the dunes of Kearney buckwheat large enough to use at the SMRA from about 16,000 to be heavily impaired due to loss of support a population of the butterfly. No persons in 1981 to over 40,000 persons vegetative cover from recreational use Kearney buckwheat plants have been in 2003 (BLM 2003). The petition notes and abuse. The petition notes that in observed on any of these surveys, and that as early as 1985, motorized this assessment, The Nature the surveyors concluded that if the plant recreation by motorcycles, four wheel Conservancy found that running were present, its population is so small drive vehicles, three wheelers, and dune vehicles at high speeds over large that it would not provide suitable buggies accounted for over 90 percent of perennial plants, in particular, was a habitat for the Sand Mountain blue the total visits to the SMRA (BLM 1985). significant source of stress to the Sand The 2003 BLM data provided by the butterfly. The petition relies on Mountain dune system. The petitioners petitioners also show an increase in communication from a species expert, note that Kearney buckwheat plants are route proliferation from about 20 mi (32 Claudia Funari of the U.S. Bureau of intentionally targeted because they km) of off-road vehicle trails in 1981 to accumulate sand at their base, thereby Land Management (BLM) to further state about 200 mi (320 km) in 2003. The that no other habitat exists within the forming natural jumps. We have petition includes four figures (maps) determined that the report to the Service flight range of the butterfly. In our files that document the proliferation of the we have an electronic message which cited as Brussard (1995) actually states route system based on a BLM analysis ‘‘as long as the foodplant remains as corroborates this claim (Funari 2004). of satellite imagery from 1978, 1994, Furthermore, information from our files abundant as it is now in the overall 1999, and 2002 (BLM 2003). In addition dune area, we saw no particular threat indicates that butterflies of the family to the overall proliferation of off-road to the continued existence of the Lycaenidae are known to have limited vehicle routes documented by the butterfly.’’ However, despite the dispersal distances (Arnold 1983, imagery, the maps clearly show an inaccurate characterization of this letter Peterson 1994 as cited in Peterson increase in the amount of habitat in the petition, the statement does imply 1996). While in some cases they may fragmentation and an expansion of the that should the abundance of Kearney employ a stepping-stone method of off-road vehicle route system from the buckwheat decline, a circumstance for hopping to habitat patches, increasing more accessible southern end of the which the petitioners have provided the likelihood of dispersing further and main dune into shrub habitat toward the significant evidence, the loss of this expanding their range, the petitioners north and northeast that had been critical foodplant would be a threat to have provided substantial survey relatively undisturbed as recently as the continued existence of the butterfly. information indicating no populations 1994. Thus, while about 1,000 ac (405 The petition also provides numerous of the host plant or the Sand Mountain ha) of potential butterfly habitat may citations from scientific literature that blue butterfly occur within a 62.5 mi remain, an estimated reduction in document the effects of off-road vehicles (100 km) radius of Sand Mountain. habitat of about 50 percent based on our on terrestrial habitats in arid Thus, it is unlikely given their life visual comparison of 1978 and 2002 environments, including sand dunes. history, ecology, and dispersal satellite imagery, much of this The effects include the elimination of a capabilities that the Sand Mountain remaining habitat is highly fragmented tiger beetle that was once widespread blue butterfly would be found beyond by the extensive trail system that has and abundant along beaches (Black and this distance. been created. Furthermore, the off-road Vaughn 2003); significant reductions in The petition claims that the Sand vehicle use that has led to this reduction in and fragmentation of habitat the number, density, and cover of Mountain blue butterfly occurs only continues to this day and poses an plants, including shrubby perennials within the Sand Mountain Recreation ongoing threat to the viability of the (Bury and Luckenbach 1983); and direct Area (SMRA), a BLM designation that Sand Mountain blue butterfly. impacts on desert vegetation (Stebbins encompasses 4,795 acres (ac) (1,940 The petition also cites observations 1995; Lathrop 1983; Lathrop and hectares (ha)), and, according to the over the past 25 years noting the effects Rowlands 1983). Documentation also petitioners, is about 1.0 mi (1.6 km) of off-road vehicles on the Sand indicates that natural recovery rates of wide and 3.5 mi (5.6 km) long. It notes, Mountain dune shrub habitat and, in perennial vegetative cover damaged by however, that Kearney buckwheat, the particular, on the Kearney buckwheat. off-road vehicles in arid environments larval host plant on which the butterfly These include: (1) A letter documenting can take decades and, in some cases, depends, has a patchy distribution and the extirpation of all plant life from an may require centuries (Lathrop and much of the area is open sand. The area 150 ft (46 m) wide along the edge Rowlands 1983; Kockelman 1983; Webb petition includes a map as Figure 4 that of the main dune over a period of and Wilshire 1983). shows dune shrub habitat extending several years (Giuliani 1977); (2) a None of these citations provides onto BLM lands adjacent to the memorandum reporting that up to half specific evidence of a direct significant designated boundary of the SMRA (BLM of 58 individual Kearney buckwheat threat to the Sand Mountain blue 2003). The petitioners claim that the plants inspected on the south side of the butterfly. The papers by Bury and Sand Mountain blue butterfly is mountain had been crushed and broken Luckenbach (1983, pp. 211–213), dependent on 1,000 ac (405 ha) of off at the ground surface and were either Lathrop (1983, pp. 157–164), Lathrop Kearney buckwheat habitat is supported dead or in the process of resprouting and Rowlands (1983, pp. 138–141, 144– by a report referenced in the petition from the rootstocks (USFWS 1994); (3) 146), and Stebbins (1995, pp. 471–472), that states that between 1,000 ac (405 a report to the Service from a research however, do provide documentation ha) and 1,600 ac (647 ha) of dune shrub scientist at the University of Nevada, that off-road vehicles can damage and habitat occur inside and outside the Reno (Brussard 1995 (cited incorrectly destroy plants, and result in significant SMRA (BLM 2004). This dune shrub as Brussard 1996 in the petition)) stating decreases in plant numbers, density, habitat is comprised of 13 shrub species, that a continued decline of the Kearney and cover of plants, including shrubby

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perennials at various sites in the not indicate whether this critical aspect introduced wildlife have affected other western North American deserts. of population structure was considered. butterfly species with small population The papers by Lathrop and Rowlands We conclude that the petition sizes, but provide no data to support (1983, p. 143) and Kockelman (1983, p. provides substantial information to these claims, and note that no 3) also provide a timeframe for support the claim that off-road vehicle information on the potential impacts of understanding natural recovery rates of use at Sand Mountain presents direct disease or predation to the Sand habitats damaged by off-road vehicle and indirect threats to the dune shrub Mountain blue butterfly is available. use in arid environments. Recovery of habitat with Kearney buckwheat on damaged vegetation is a process of which the Sand Mountain blue butterfly D. Inadequacy of Existing Regulatory critical importance to the Sand depends. In particular, data provided to Mechanisms Mountain blue butterfly because it the petitioners by the BLM (2003) The petition claims that the BLM has depends on the presence of its host reliably documents that within the past failed to protect habitat for the Sand plant, the Kearney buckwheat, on an 25 years a progressive loss of dune Mountain blue butterfly from excessive annual basis in order to reproduce. shrub habitat, continuing fragmentation off-road vehicle use over the past 25 Based on the data provided by the of dune shrub habitat, and an ongoing years, and cites a public comment letter petitioners (BLM 2003, 2004), we expansion of the route system into dune on the 1978 draft SMRA which states estimate that the habitat on which the shrub habitat previously considered concern over the potential impacts to Sand Mountain blue butterfly depends secure for the butterfly has occurred. the invertebrate fauna of the dune has been reduced by as much as 50 The data presented in the petition system and notes that the management percent over the past 25 years and that, document that annual visitor use has plan fails to adequately take into at most, 1,000 ac (405 ha) of potential, more than doubled and the route system account biological considerations but highly fragmented, habitat remains. has expanded from 20 miles (32 km) to (Hardy 1978). These studies provide reliable over 200 miles (320 km) over this time The petition also cites a mid-1990s documentation that even if off-road period. The petition presents an effort by the BLM, the Service, and vehicle use were to be eliminated from estimate, based on a personal others to assess the status of the Sand Sand Mountain, natural recovery of the communication from the BLM Mountain blue butterfly in response to Kearney buckwheat habitat may take (Tonenna, no date), that a maximum of a complaint that off-road vehicles were decades, a time frame that poses an about 1,000 ac (405 ha) of dune shrub posing a threat to its existence by indirect threat to the long-term viability habitat remain, and notes that the impacting its host plant (Austin 1990). of a species that must reproduce Kearney buckwheat, on which the Sand The initial outcome of this effort was a annually. Mountain blue butterfly depends, has a determination that no emergency action The petition also claims that off-road patchy distribution within the was necessary because, during the vehicles alter the hydrology of dune remaining, highly fragmented habitat. course of the assessment, the Kearney systems by exposing clay layers that The petitioners also reference a report buckwheat was found to be much more create an impermeable barrier to the that provides reliable information common than previously believed, percolation of precipitation into the soil. indicating that at the time of the particularly in the northeastern portion Further vehicle impacts break the clay petition, an estimated 1,000 to 1,600 ac of the dune system. Instead, the BLM layer and precipitation percolates to (405 to 647 ha) of dune shrub habitat and Service decided to institute a depths where it is beyond the reach of remained in which Kearney buckwheat monitoring plan in order to avoid an seedlings attempting to establish is a component (BLM 2004, p. 4). We emergency situation in the future (BLM (Tonenna no date). No data are provided estimate, based on the data presented in 1995, p. 1). The monitoring plan to support this claim; therefore, we the petition (BLM 2003, 2004), about 50 consisted only of establishing consider it speculative. The petition percent of the dune shrub habitat may permanent photographic points. Due to also claims that constant disruption of have been destroyed or altered over this personnel changes in both agencies, the soil surface makes it difficult or 25-year time span. The off-road vehicle monitoring was discontinued after a few impossible for seeds to germinate. We use that has led to this reduction in and years. In recent years, the photographic agree the germination process would be fragmentation of habitat continues to points have been revisited and found to made difficult or impossible under this day and poses a significant and reliably document the ongoing frequent disturbance by vehicles. The ongoing threat to the continued viability alteration and destruction of shrub petition claims that this could be the of the Sand Mountain blue butterfly. habitat (Tonenna 2006). primary reason for a reported skew in The petition notes that in the Spring Kearney buckwheat populations at Sand B. Overutilization for Commercial, of 2002, BLM staff recommended that Mountain toward older shrubs. The Recreational, Scientific, or Educational some areas of Sand Mountain be closed petition provides no documentation to Purposes to protect the Sand Mountain blue support this claim. The persistence of The petition claims collection by butterfly. As a result, a group comprised some plant species may depend on overzealous lepidopterists is a potential of BLM and Service staff, episodic years of strong recruitment threat because of the rarity of the Sand representatives from conservation and (Brigham and Thomson 2003, p. 154). Mountain blue butterfly. While we have off-road vehicles groups, and Episodic regeneration was not found to accepted the claim that the Sand representatives of the Fallon-Paiute be characteristic of several plants Mountain blue butterfly occurs only at Shoshone Tribe, who consider Sand studied in the cold deserts of the Great Sand Mountain, the petition does not Mountain sacred, proposed that 1,000 ac Basin in which Sand Mountain is provide any data to substantiate the (405 ha) be closed to off-road vehicles located (West et al. 1979, pp. 384–385). claim that the species is threatened by while keeping the more popular off-road The same researchers, however, also collection. riding areas open. No action was taken found no correlation between plant size on this proposal. and plant age, and that plants that C. Disease or Predation The petitioners claim that in 2003, the appear even-aged because of their The petitioners claim that diseases BLM implemented an emergency action similar size are often uneven-aged (West affecting larval host plants and to protect and restore the sand dune et al. 1979, pp. 386). The petitioners do butterflies, and predation by native and ecosystem that included the following

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six main actions: (1) Continue to E. Other Natural or Manmade Factors evidence presented that the Sand manage the SMRA under the existing Affecting the Species’ Continued Mountain blue butterfly population off-road vehicle designation; (2) develop Existence fluctuates in response to weather. We programs and practices that encourage The petition claims that invasive acknowledge that habitat alteration may off-road vehicle users to prevent plants, and particularly Russian thistle exacerbate normal population disturbance of Kearney buckwheat (Salsola kali), pose a threat to the Sand fluctuations, and that this may make the habitat within and outside of the SMRA; Mountain blue butterfly because the fuel Sand Mountain blue butterfly, a species (3) begin efforts to restore and load it produces when dry increases the likely to experience large population rehabilitate disturbed Kearney potential for wildfire. The petitioners fluctuations (Murphy 2006), more buckwheat habitat within and outside of also claim that Kearney buckwheat is susceptible to extinction. There is no evidence provided, however, that this the SMRA; (4) identify existing not adapted to resist fire, and fire could has occurred, or is occurring, and disturbed travel routes through the kill or seriously damage plants since therefore we do not find this threat to wildfires have not occurred historically Kearney buckwheat habitat to connect be substantial. off-road vehicle use areas within and at Sand Mountain. An increase in outside the SMRA and discontinue off- Russian thistle, therefore, would Finding road vehicle use in habitat outside these increase the risk that a fire may occur We have reviewed the petition and travel routes; (5) continue scientific and habitat for the Sand Mountain blue literature cited in the petition, and investigations into the Sand Mountain butterfly would be destroyed (Tonnena evaluated that information. On the basis ecosystem, including studies of the no date). of this review and evaluation, we find natural history of the plants and Russian thistle is known to occur at that the petition does present Sand Mountain and, when dried, is , restoration techniques, and substantial information to indicate that highly combustible. However, the monitoring technology; and (6) initiate a listing the Sand Mountain blue butterfly petition provides no data to support the may be warranted. The Sand Mountain revised management plan for the Sand claim that it is so widespread as to Mountain landscape to update the butterfly is known only from Sand constitute a significant threat to either Mountain, Nevada, where it is closely current Recreation Area Management the Kearney buckwheat or the Sand Plan, reflecting the increasing amount associated with its host shrub, the Mountain blue butterfly. Nor does the Kearney buckwheat. Adult butterflies, and variety of uses and demands of the petition provide documentation for the which survive only a few weeks, deposit area. claim that Kearney buckwheat is not their eggs on the Kearney buckwheat, The primary claim that the petitioners adapted to resist fire. Elsewhere in the which is the only food for the larvae make regarding this strategy is that petition, the petitioners note that (caterpillars) that hatch the following compliance with the encouraged off- Kearney buckwheat has an extensive spring. Larvae likely pass through road vehicle route system is voluntary branching caudex from a deep, woody several stages of molting, emerging and unenforceable, and therefore taproot (Reveal 2002). It is at least larger each time, with each stage ineffective in preventing further habitat possible that this taproot, buried dependent on the availability of the decline. They cite data from a 2004 BLM beneath sand, would survive and food resource. The final molt results in report that documents noncompliance resprout after fire, as it has been a pupa which attaches to a twig or other occurring throughout the area with all observed to do after damage to the surface and from which the adult above-ground shoots (USFWS 1994). We routes continuing to be used based on emerges resource (Scott 1986, p. 21). do not, therefore, find the petition to 15 weeks of compliance monitoring. The annual continuance of the butterfly provide substantial information to Impacts to shrub vegetation continued population larvae, therefore, depends support the claim that invasive plants entirely upon this food. with multiple vehicles riding through and/or fire currently pose a significant An estimated 1,000 ac (405 ha) of vegetation despite alternative existing threat to the Sand Mountain blue dune shrub habitat remained in 2003, an routes nearby that avoid vegetation. The butterfly. estimated reduction of about 50 percent petitioners note that Kearney buckwheat In addition, the petition notes that over the past 25 years. Moreover, much plants are intentionally targeted because most populations normally of this remaining habitat has been sand accumulates around the base experience large fluctuations in size highly fragmented by over 200 miles forming natural jumps. The report states (Ehrlich 1992; Schultz 1998), and that (320 km) of off-road vehicle routes. This that educational efforts and increased weather, predation, and disease may reduction and fragmentation of habitat signage are routinely ignored, and, cause annual changes of an order of correlates with a significant increase in although there does seem to have been magnitude or more. The petition claims off-road vehicle recreational use of the some level of compliance as a result of that these normal population area over the same time period. the management changes, ‘‘there is still fluctuations, in combination with Recreational use continues to increase, significant noncompliance that will habitat alteration or loss, can result in and all areas of the Kearney buckwheat likely continue the trend of vegetation population extirpations (Hanski et al. habitat upon which the Sand Mountain loss and prevent the rehabilitation of the 1995) and that, because of its extremely blue butterfly depends remain open to area’’ (BLM 2004). limited geographic area, the butterfly is off-road vehicle use as a result of extremely vulnerable to extinction. inadequate regulatory mechanisms. The We have reviewed all of the sources We acknowledge that insect reduction and fragmentation of Kearney cited in the petition and have concluded populations may experience normal buckwheat habitat, therefore, represents that they provide substantial large population fluctuation, although a direct reduction in the food critical to information that existing regulatory the petition provides no data specific to the survival of the larvae and their mechanisms may be inadequate to the Sand Mountain blue butterfly. We subsequent emergence as reproductive prevent the progressive decline of the have previously, under Factor C, noted adults. As the food supply diminishes, habitat on which the Sand Mountain that there is no evidence to support the fewer larvae survive and fewer adults blue butterfly depends. claim that disease or predation are are produced, which in turn is likely to threats to the butterfly. Nor is there any result in fewer eggs being deposited.

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Over time this will result in smaller and for critical habitat designation when Author smaller population levels as habitat listing species. If we determine in our The primary author of this notice is destruction continues. Thus, there is 12-month finding that listing the Sand the Nevada Fish and Wildlife Office (see substantial information presented in the Mountain blue butterfly is warranted, ADDRESSES). petition that the reduction in available we will address the designation of habitat is leading to a decrease in critical habitat at the time of the Authority population that will continue over time, proposed rulemaking. The authority for this action is section thus increasing the risk of extinction. 4 of the Endangered Species Act of References Cited Therefore we conclude that the petition 1973, as amended (16 U.S.C. 1531 et has presented substantial information A complete list of all references cited seq.). that listing may be warranted for this species. We will initiate a status review herein is available, upon request, from Dated: July 28, 2006. to determine whether listing is the Nevada Fish and Wildlife Office (see Kenneth Stansell, warranted. ADDRESSES). Acting Director, U.S. Fish and Wildlife The petitioners also requested that Service. critical habitat be designated for this [FR Doc. E6–12577 Filed 8–7–06; 8:45 am] species. We always consider the need BILLING CODE 4310–55–P

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