Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition to List the Amargosa Toad (Bufo nelsoni, 46551-46557 [E9-21762]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 74, Number 174 (Thursday, September 10, 2009)]
[Proposed Rules]
[Pages 46551-46557]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-21762]


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

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R8-ES-2009-0047]
[MO 92210530083-B2]


Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition to List the Amargosa Toad (Bufo nelsoni) as Threatened or 
Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day 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 the Amargosa toad (Bufo nelsoni) 
as threatened or endangered under the Endangered Species Act of 1973, 
as amended (Act). We find that the petition presents substantial 
scientific or commercial information indicating that listing this 
species may be warranted. Therefore, with the publication of this 
notice, we are initiating a status review to determine if listing the 
Amargosa toad is warranted. To ensure that the status review is 
comprehensive, we are soliciting scientific and commercial data and 
other information regarding this species.

DATES: We made the finding announced in this document on September 10, 
2009. To allow us adequate time to conduct this review, we request that 
we receive information on or before November 9, 2009.

ADDRESSES: You may submit information by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. Follow the instructions for submitting comments.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R8-ES-2009-0047; Division of Policy and Directives 
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, 
Suite 222; Arlington, VA 22203.
    We will not accept e-mail or faxes. We will post all information 
received on https://www.regulations.gov. This generally means that we 
will post any personal information you provide us (see the Information 
Solicited section below for more details).

FOR FURTHER INFORMATION CONTACT: Robert D. Williams, Field Supervisor, 
Nevada Fish and Wildlife Office, 4701 North Torrey Pines Drive, Las 
Vegas, NV 89130, by telephone (702-515-5230), or by facsimile (702-515-
5231). Persons who use a telecommunications device for the deaf (TDD) 
may call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Information Solicited

    When we make a finding that a petition presents substantial 
information indicating that listing a species may be warranted, we are 
required to promptly commence a review of the status of the species. To 
ensure that the status review (12-month finding) is complete and based 
on the best available scientific and commercial information, we are 
soliciting information concerning the status of the Amargosa toad. We 
request information from the public, other concerned governmental 
agencies, Native American Tribes, the scientific community, industry, 
or any other interested parties concerning the status of the Amargosa 
toad. We are seeking information regarding:
    (1) The species' historical and current status and distribution, 
its biology and ecology, and ongoing conservation measures for the 
species and its habitat.
    (2) Information relevant to the factors that are the basis for 
making a listing determination for a species under section 4(a) of the 
Act (16 U.S.C. 1531 et seq.), which are:

[[Page 46552]]

    (a) The present or threatened destruction, modification, or 
curtailment of the species' 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.
    (3) Any proposed projects or development plans that may result in 
increased water use in the Oasis Valley.
    (4) Information on methods to control crayfish (Procambarus spp.) 
in desert riparian systems.
    (5) Information on effects of mosquitofish on eggs and larvae of 
the Amargosa toad or other species of toad where mosquitofish are not 
native.
    (6) Data on surface water quality or groundwater monitoring in the 
Oasis Valley, including transport or movement of environmental 
contaminants from mining operations and the Nevada Test Site.
    (7) Information on whether or not UV-B radiation is increasing in 
the Oasis Valley and, if so, the effects of this increase on Amargosa 
toads.
    (8) Information as to any other threats to Amargosa toads asserted 
in the petition.
    If we determine that listing the Amargosa toad is warranted, it is 
our intent to propose critical habitat to the maximum extent prudent 
and determinable at the time we propose to list the species. Therefore, 
with regard to areas within the geographical range currently occupied 
by the Amargosa toad, we also request data and information on what may 
constitute physical or biological features that are essential to the 
conservation of the species, where these features are currently found, 
and whether any of these features may require special management 
considerations or protection. In addition, we request data and 
information regarding whether or not there are areas outside the 
geographical area occupied by the species that are essential to the 
conservation of the species. Please provide specific comments and 
information as to what, if any, critical habitat you think we should 
propose for designation if the species is proposed for listing, and why 
such habitat meets the requirements of the Act.
    Please note that 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, as 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.'' Based on the status review, we will issue 
a 12-month finding on the petition, as provided in section 4(b)(3)(B) 
of the Act.
    You may submit your information concerning this status review by 
one of the methods listed in the ADDRESSES section. We will not 
consider submissions sent by e-mail or fax or to an address not 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 website. If your submission is made via 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 materials we receive, as well as supporting 
documentation we used in preparing this finding, will be available for 
public inspection on https://www.regulations.gov, or by appointment 
during normal business hours, at the U.S. Fish and Wildlife Service, 
4701 North Torrey Pines Drive, Las Vegas, NV.

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 at 
the time we make the determination. 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 commence a status review of the species.
    On February 27, 2008, we received a petition dated February 26, 
2008, from the Center for Biological Diversity and Public Employees for 
Environmental Responsibility (PEER; hereinafter referred to as 
``petitioners'') requesting that the Amargosa toad be listed as 
endangered or threatened under the Act. The petition clearly identified 
itself as such and included the requisite identification information 
for the petitioners, as required in 50 CFR 424.14(a). In a letter to 
the petitioners dated May 1, 2008, we responded that we had reviewed 
the petition and found that an emergency listing was not warranted. We 
also stated that, although we were currently required to complete a 
significant number of listing and critical habitat actions, we 
anticipated making an initial finding on the petition during Fiscal 
Year 2008. However, due to unforeseen delays, we were not able to 
complete the finding at that time. This notice constitutes our initial 
finding on the petition.

Previous Federal Actions

    On August 2, 1977, the Service included the Amargosa toad on a list 
of amphibians that we were reviewing to determine whether those species 
should be proposed for listing as endangered or threatened (42 FR 
39121). Subsequently, beginning in 1982, we assigned the Amargosa toad 
as either a category 1 or category 2 candidate species under the Act 
(47 FR 58454, December 30, 1982; 50 FR 37958, September 18, 1985; 54 FR 
554, January 6, 1989; 56 FR 58804, November 21, 1991; 59 FR 58982, 
November 15, 1994). A category 1 species was a taxon for which the 
Service has substantial information on hand to support the biological 
appropriateness of proposing to list as endangered or threatened under 
the Act. A category 2 species was a taxon for which the Service has 
information indicating that proposing to list the species as endangered 
or threatened is possibly appropriate, but that information is not 
conclusive data on biological vulnerability or threats that would 
support a proposed listing.
    On September 21, 1994, the Service received a petition from the 
Biodiversity Legal Foundation of Boulder, Colorado, requesting 
emergency listing of the Amargosa toad as endangered. At the time we 
received the petition, the Amargosa toad was a category 1 candidate 
species. On March 23, 1995, we announced our 90-day finding that the 
petitioned action may be warranted and initiated a status review of the 
species (60 FR 15280). On July 26, 1995,

[[Page 46553]]

the Service recommended removal of the Amargosa toad from category 1 
candidate status based on information we obtained during the status 
review. On February 28, 1996 (61 FR 7596), we removed the Amargosa toad 
from candidate status. On March 1, 1996, we announced our 12-month 
finding that listing the Amargosa toad as endangered or threatened was 
not warranted (61 FR 8018).

Species Information

Taxonomy and Description

    The Amargosa toad is a member of the family Bufonidae which 
includes North American true toads. Stejneger (1893, cited in Lannoo 
2005, p. 427) described the Amargosa toad as Bufo boreas nelsoni, a 
subspecies of the western toad (Bufo boreas). Savage (1959, pp. 251-
254) was the first to refer to the Amargosa toad as Bufo nelsoni in 
accordance with the rules of the International Code of Zoological 
Nomenclature. Feder (1997, cited in Lannoo 2005, p. 428) diagnosed Bufo 
nelsoni by allozymic data and was the first to publish species rank for 
the Amargosa toad. Mitochondrial DNA analyses by Goebel (1996, cited in 
Lannoo 2005, p. 429) are consistent with species status for the 
Amargosa toad. In 2002, Bufo nelsoni was listed as a full species on 
the Integrated Taxonomic Information System database compiled by the 
Smithsonian Institution with the highest credibility rating by their 
Taxonomic Working Group (Lannoo 2005, p. 427).
    Adult male Amargosa toads are typically 1.6 to 2.7 inches (in.) (42 
to 68 millimeters (mm)) snout-vent length, females typically 1.8 to 3.5 
in. (46 to 89 mm) snout-vent length (Nevada Department of Wildlife 
[NDOW] 2000a, p. A-2). The dorsal body of the Amargosa toad has three 
paired rows of tubercles, or wart-like skin projections, with brown 
center coloration. The back has black speckling or asymmetrical spots. 
Background coloration ranges from almost black to brownish or buffy 
olive and may vary considerably among individual toads in the same 
population. A light mid-dorsal stripe occurs along the backbone. The 
large, wart-like parotid glands located behind the eye are tawny to 
olive. Underneath, the Amargosa toad is whitish or pale olive with 
scattered black spots that merge above the legs to form the appearance 
of ``pants.''

Historical and Current Range

    Amargosa toads are endemic to Oasis Valley in southern Nye County, 
Nevada. The area occupied by the Amargosa toad is isolated with no 
known or probable connections to members of the western toad complex 
(NDOW 2000a, p. A-1). The nearest known record for a western toad is 
approximately 35 linear miles (56 kilometers (km)) away at Furnace 
Creek in Death Valley National Park, California, where an introduced 
population of western toad occurs. The historical and current range of 
the Amargosa toad is estimated to be a 10-mile (16-km) stretch of the 
Amargosa River and nearby spring systems roughly between the towns of 
Springdale and Beatty. In 1996, the Amargosa Toad Working Group (ATWG) 
was organized to provide recommendations for management and 
conservation of the Amargosa toad. The ATWG consists of representatives 
of the Service, NDOW, Nevada Department of Conservation and Natural 
Resources, Bureau of Land Management (BLM), Nye County and local 
community, the University of Nevada at Reno, and other stakeholders. In 
2007, the ATWG prepared a map of all known and potential habitat for 
the species, including potential movement corridors, and posted the map 
on the Internet at: https://www.fws.gov/nevada/nv%5Fspecies/amargosa_toad.html. The total amount of known and potential Amargosa toad 
habitat delineated on the ATWG map is 8,440 acres (ac) (3,416 hectares 
(ha)).

Life History and Ecology

    Amargosa toad habitat requirements for breeding and population 
recruitment include the presence of open, ponded or flowing water, with 
riparian vegetative cover in an early to intermediate successional 
stage to form a partial canopy for shade with minimal emergent 
vegetation at the water's edges. Immature (metamorphs or toadlets) and 
adult Amargosa toads are dependent upon the areas described above as 
well as areas they can use for shelter, including burrows, debris 
piles, spaces under logs or rocks, or areas of dense vegetation (NDOW 
2000a, p. A-2). Adult toads also require adjacent vegetated uplands for 
nocturnal foraging. Upland habitat typically consists of Mojave and 
Great Basin desert vegetation with leaf litter, rock outcrops, rodent 
burrows, woody debris, and open areas that are sparsely vegetated. 
Dense vegetation and advanced successional stages of riparian 
vegetation appear to limit habitat suitability and occupancy by all 
life stages, particularly where open water is not present (NDOW 2000a, 
p. A-2).
    The breeding season for the Amargosa toad begins in mid-February 
and may extend into July during which time adults congregate at 
breeding sites. Jones (2004, p. 19) found 82 percent of clutches were 
laid from February 27 to March 23 in the 2001 season. Eggs are 
deposited in strings among vegetation in shallow water. A female may 
lay up to 6,000 eggs in a single clutch. The eggs typically develop 
into larvae (tadpoles) within 1 to 2 weeks, but as quickly as 3 days in 
thermal waters (NDOW 2000a, p. A-2). Larvae are blackish with silvery 
speckles, rounded tail tips, and translucent tail fins. Larvae feed on 
algae, decaying plant material, and organic detritus that is suspended 
in the water column or on the substrate. Larvae may be swept downstream 
if a current is present. Larval mortality may be very high, although 
recruitment estimates have not been made (CBD and PEER 2008, p. 10). 
Amargosa toad tadpoles require relatively open water that persists long 
enough for the completion of metamorphosis and development into 
toadlets at which time they leave the water. Tadpoles metamorphose into 
toadlets in about 4 to 8 weeks, though development is highly variable 
depending on water temperature and site conditions (Jones 2004, p. 7). 
Predation and early desiccation of wetlands needed for breeding may 
destroy an entire breeding effort. Amargosa toads are believed to 
typically live 3 to 4 years in the wild, but a toad marked in 1998 was 
recaptured in 2008.
    Amargosa toads may be active any time of the year. Toads eat 
invertebrates including spiders, scorpions, ants, harvester ants, 
wasps, beetles, flies, grasshoppers, stink bugs, water striders, damsel 
flies, mosquitoes, mites, and snails. They use their sticky tongue to 
grab prey items in a sit-and-wait predator strategy (CBD and PEER 2008, 
p. 11).
    The mean home range of adult Amargosa toads has been studied at the 
Torrance Ranch site and at Amargosa River Narrows. Home ranges at these 
sites are estimated to be approximately 1.5 ac (0.6 ha), with no 
difference between males and females (Jones 2004, p. 48). Rare 
movements occur over 0.8 mile (1.3 km) between breeding sites along the 
Amargosa River and 0.5 mile (0.8 km) across uplands (NDOW 2000b, p. 9). 
During rain events, toad movements are not always confined to riparian 
corridors and reports exist of Amargosa toads moving over upland ridges 
(Jones 2004, p. 49). However, significant genetic differentiation of 
Amargosa toads among sites suggests Amargosa toads do not make 
extensive use of upland habitat for movement or migration (Simandle 
2006, p. 38). Amargosa toads are attracted to

[[Page 46554]]

disturbed areas where they forage and breed (NDOW 2000b, pp. 7-8 and 
19), and seemingly co-exist with humans as indicated by survey data 
collected at developed study sites (urban and residential).
    Predators of toads include common raven (Corvus corax), white-faced 
ibis (Plegadis chihi), great egret (Ardea alba), snowy egret (Egretta 
thula), great blue heron (Ardea herodias), red-tailed hawk (Buteo 
jamaicensis), red-shouldered hawk (Buteo lineatus), spotted sandpiper 
(Actitis macularius), American robin (Turdus migratorius), American 
badger (Taxidea taxus), crayfish (Procambarus spp.), and various fish 
species (CBD and PEER 2008, p. 11).

Status

    Since 1998, the Amargosa toad has been classified as a Protected 
Species by the State of Nevada. No Federal protection is currently 
afforded the species other than designation as a Special Status Species 
by the BLM. Conservation and management oversight for the Amargosa toad 
is provided through the ATWG. The ATWG is comprised mostly of 
biologists, managers, and private landowners with a common interest in 
Amargosa toad conservation. The Amargosa Toad Conservation Agreement 
and Strategy was completed in 2000 (CA/S) (NDOW 2000a, pp. 1-12) and 
provides management and conservation guidance for the Amargosa toad. 
Efforts to update the CA/S were initiated at the November 7, 2007, 
meeting of the ATWG.
    In 1998, the Nevada Department of Wildlife (NDOW) initiated a long-
term population monitoring program for the Amargosa toad using mark/
recapture methods at key sites. The study involves capture and marking 
(with implanted tags) of all adult Amargosa toads found that are 2 in. 
(50 mm), or greater in length. As of November 2007, a total of 5,666 
Amargosa toads had been captured and tagged since 1998. The 2007 
estimate for the number of toads 2 in. (50 mm) or greater in length 
from all surveyed sites is 5,179, which is 13 percent less than the 
estimate for 1998 through 2006 (Hobbs 2007, p. 1). Further, additional 
populations of toads may occur on unsurveyed sites on private land 
(NDOW 2000b, p. 18).
    Simandle (2006, p. 42) determined that Amargosa toads meet the 
criteria and expectations of metapopulations. This means that occupied 
habitats, unoccupied but suitable habitats, and intervening habitat 
that may be occasionally used during infrequent migration events should 
all be considered as conservation priorities. Rare events such as 
intense floods demonstrate that these are dynamic, disturbance-
dependent ecological systems upon which the Amargosa toad depends. 
Events such as floods may simultaneously destroy existing occupied 
habitat, create new suitable habitat, and facilitate infrequent 
movement among different sites.

Five Factor Evaluation

    Section 4 of the Act, and its implementing regulations at 50 CFR 
424, set forth the criteria and procedures for adding species to the 
Federal Lists of Endangered and Threatened Wildlife and Plants. The 
Service determines whether a species is an endangered or threatened 
species due to one or more of the following 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 making this 90-day finding, we evaluated whether information 
regarding the Amargosa toad, as presented in the petition and other 
information available in our files at the time of the petition review, 
meets the definition of substantial information as stated in 50 CFR 
424.14(b)(1), indicating that the petitioned action may be warranted. 
Our evaluation of this information is presented below.

Factor A.

Present or Threatened Destruction, Modification, or Curtailment of the 
Species' Habitat or Range

    The petition outlines numerous assertions regarding the present or 
threatened destruction, modification, or curtailment of the Amargosa 
toad's habitat or range. Several assertions point to Amargosa toad 
habitat being threatened by proposed Federal land sales and by 
development projects on private land. The petitioners claim that 
federal land proposed for sale and private lands subject to development 
encompass the majority of the range of the Amargosa toad (CBD and PEER 
2008, pp. 3, 19, and 29). The petition states that threats to the 
Amargosa toad resulting from federal land sales are the development 
that would take place on these and the surrounding private lands, and 
the increased demand for groundwater to support that development (CBD 
and PEER 2008, pp. 3, 17, and 20).
    The petition raises the issue of potential development plans for 
the Town of Rhyolite that would include the need for water (CBD and 
PEER 2008, p. 20). Indian Spring has been identified as a potential 
water extraction site that would support Rhyolite development. The 
petition states that if this were to occur, it would likely adversely 
affect the water table at that site.
    The petition also states that the proposed Reward Mine on BLM land 
has the potential to affect groundwater in the area. The Reward Mine is 
approximately 3 miles (4.8 km) southeast of the Amargosa River at the 
Narrows, south of Beatty. The mine operations would use up to 287 acre-
feet of groundwater per year over a period of 6 years (John Shomaker 
and Associates, Inc. 2008, p. 1). The petitioners claim that proposed 
water withdrawal potentially may create a cone of depression that could 
lower water levels upstream and impact toad habitat. The February 2008 
analysis provided by BLM on the Reward Mine indicates water for 
operations would be provided by a well in alluvium next to the Amargosa 
River (John Shoemaker & Associates Inc. 2008, p. 1). The petitioners 
assert the combination of river water and local groundwater extracted 
from the well could lower groundwater levels in Oasis Valley 
(particularly southern Oasis Valley); however, the petitioner did not 
provide any support for these assertions.
    The petitioners assert that lowering of the water table from 
increased groundwater use could seriously impact toad habitat (CBD and 
PEER 2008, p. 17). Further, they claim that portions of the Amargosa 
River may have become dewatered from overuse by humans (CBD and PEER 
2008, p. 17). A detailed analysis of the impacts of groundwater and 
surface water withdrawals on water levels in the Amargosa River would 
be required to demonstrate the above effects. There is no indication in 
our files or submitted with the petition that such an analysis has been 
completed. However, we have in our files a 1998 ruling on an 
application for groundwater withdrawal in the Oasis Valley issued by 
the Nevada State Engineer (NSE). This ruling recognized a high degree 
of connection between groundwater and surface water in Oasis Valley 
(NSE Ruling 4669). The NSE found that combined groundwater and surface 
water allocations significantly exceeded the current estimate of 
perennial yield in the basin. Proposed land uses and development in and 
near the area of Oasis Valley could lead to additional groundwater 
allocations, accompanied by a reduction in

[[Page 46555]]

Amargosa toad habitat through a lowering of local groundwater levels. A 
small decrease in groundwater levels in Oasis Valley could lead to a 
significant reduction in the area of open pools of water at springs, 
along spring branches, or along the Amargosa River (particularly during 
dry summer months), all of which provide habitat for the Amargosa toad 
(Braumiller 2008, p. 1). Therefore existing and future water use in the 
Oasis Valley may pose a threat to the Amargosa toad.
    Other potential threats identified by the petitioners include 
alterations of the riparian corridor that may affect toad movements and 
habitat connectivity; habitat loss and fragmentation resulting from 
proposed projects including flood control projects, a railroad, and a 
mineral material site; overgrowth of vegetation as a result of fencing; 
feral burro and livestock effects on springs and toads; direct 
mortality associated with roads and highways; and off-highway vehicle 
(OHV) use.
    The petitioners generally describe the potential effects that could 
result from flood control projects (CBD and PEER 2008, pp. 17 and 20). 
However, the petitioners do not provide information on any specific 
flood control projects that may threaten the species or its habitat, 
and the Service is unaware of any proposed flood control actions that 
would alter the Amargosa River.
    The petitioners state that construction of a new railroad, as 
proposed by the U.S. Department of Energy to transport nuclear waste to 
Yucca Mountain, may cross the northernmost portion of the Oasis Valley, 
north of Colson pond, disturbing approximately 20 ac (8 ha) of Amargosa 
toad habitat (CBD and PEER 2008, p. 18). Although habitat is suitable, 
Amargosa toads are not known to occur in this area (ATWG 2006, pp. 1-
2).
    Vegetation overgrowth and use of springs by feral burros and cattle 
are other land management issues raised by the petitioners that may 
result in degraded habitat and depressed Amargosa toad numbers (CBD and 
PEER 2008, pp. 17-18, 21 and 23-25). Fencing has been installed at the 
Crystal and Indian springs sites to exclude feral burros. While burros 
and livestock (ungulates) may trample Amargosa toad eggs and larvae, 
light to moderate disturbance is important to Amargosa toads (ATWG 
2005, p. 2). In the absence of disturbance, vegetation grows 
uncontrolled and reduces open areas necessary for Amargosa toads. 
Intensive and uncontrolled use of Amargosa toad habitat by ungulates 
may threaten the species by resulting in habitat degradation and 
potential loss of individual Amargosa toads; however, light to moderate 
use may be beneficial to the Amargosa toad. Targeted grazing on the 
Torrance Ranch by The Nature Conservancy improved habitat, and Amargosa 
toads responded positively as indicated by use of the area by Amargosa 
toads for feeding and breeding. Complete removal of ungulates could 
lead to overgrowth of vegetation, and may pose a more serious threat to 
the Amargosa toad than moderate ungulate use.
    The petitioners claim that OHV activity has been increasing around 
the Beatty area and results in decreased habitat quality, loss of 
riparian habitats, and direct mortality of Amargosa toads (CBD and PEER 
2008, pp. 21 and 27). Most OHV use in the Beatty area, including the 
Terrible's 200 Las Vegas to Reno race, occurs during the daytime when 
toads are likely sheltering. OHVs are used by community residents 
within the town limits of Beatty mostly along existing roads and 
trails. However, OHV travel within the river corridor, washes, or other 
areas used by toads for breeding or for sheltering during daylight 
hours may impact Amargosa toads, particularly eggs and tadpoles that 
are known to occur in road depressions. Although the extent of impacts 
to the Amargosa toad as a result of OHV use is largely unknown, we 
believe this current OHV use could pose a threat to the Amargosa toad.
    In summary, we find that the information provided in the petition, 
as well as information in our files, presents substantial scientific or 
commercial information indicating that listing the Amargosa toad as 
threatened or endangered may be warranted due to the present or 
threatened destruction, modification, or curtailment of its habitat or 
range, including existing and future water development, use of 
groundwater to support land development, overgrowth of vegetation, 
excessive habitat use by ungulates, and OHV use in toad habitat. We 
will investigate whether there are additional potential threats to the 
Amargosa toad related to Factor A during our status review.

Factor B.

Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The petitioners state that there is no evidence that scientific 
research has resulted in negative consequences on studied populations 
of the Amargosa toad (CBD and PEER 2008, p. 22). We have no information 
in our files that indicates overutilization for commercial, 
recreational, scientific, or educational purposes is a threat to the 
Amargosa toad. However, we will further investigate whether 
overutilization for commercial, recreational, scientific, or 
educational purposes is a potential threat to the toad during our 
status review.

Factor C.

Disease or Predation

    The petitioners did not present evidence, and no evidence exists in 
our files, that disease may be a threat to the Amargosa toad at this 
time. However, we will further investigate whether disease is a 
potential threat to the toad during our status review.
    The petitioners claim that exotic species or nonnative predators 
and competitors, including nonnative crayfish (Procambarus spp.), 
largemouth bass (Micropterus salmoides), nonnative trout (Oncorhynchus 
spp.), black bullhead catfish (Ictalurus melas), mosquitofish (Gambusia 
affinis), and nonnative bullfrogs (Rana catesbeiana), are a serious 
threat to the Amargosa toad. Since their introduction in the mid-1980s, 
nonnative crayfish have become established along most of the Amargosa 
River and springs occupied by the Amargosa toad, and occur in large 
numbers (CBD and PEER 2008, p. 3). Crayfish consume toad eggs and 
larvae, and were located in 7 of 11 sites surveyed during a study (CBD 
and PEER 2008, p. 23; Jones 2004, pp. 24-25). Bass are known to occur 
in at least one pond on private property in Oasis Valley, but there is 
no information in our files to support the claim that trout currently 
occur in Oasis Valley. Black bullhead catfish are known at one pond 
that is also occupied by Amargosa toads. Catfish and toads have co-
occurred at this site for at least 9 years. Mosquitofish have been 
introduced into waters of Oasis Valley and occur at most sites occupied 
by toads. Mosquitofish have been observed to remove and consume eggs of 
the arroyo toad (Bufo californicus; Lannoo 2005, p. 399) and may also 
prey on Amargosa toad eggs. It is conceivable that nonnative predators 
have an impact on Amargosa toads; however, the overall effects of these 
introduced aquatic species specifically to the Amargosa toad are 
unknown.
    In summary, we find that the information provided in the petition, 
as well as information in our files, presents substantial scientific or 
commercial information indicating that listing the Amargosa toad may be 
warranted due to the threat of predation by introduced species.

[[Page 46556]]

Factor D.

Inadequacy of Existing Regulatory Mechanisms

    The petitioners cite BLM's failure to protect the Amargosa toad 
through designation of important toad habitat as an Area of Critical 
Environmental Concern (ACEC) or through provision of a comparable level 
of protection through other means (CBD and PEER 2008, pp. 19 and 27). 
Further, they claim that the Town of Beatty and Nye County have failed 
to cooperate in local community efforts to develop a conservation area 
in Oasis Valley (CBD and PEER 2008, p. 20), and, therefore, that 
Amargosa toad habitat on private land is threatened by potential 
development which may proceed without conservation for the Amargosa 
toad (CBD and PEER 2008, p. 19). Finally, the petitioners assert that 
the State of Nevada fails to provide adequate protection for the 
Amargosa toad through existing statutes particularly regarding permit 
exemptions for residential groundwater use up to 1,800 gallons per day 
and habitat threats on private lands (CBD and PEER 2008, pp. 20 and 
28).
    The petitioners also claim that BLM allows OHV racing near the 
Crystal Springs exclosure and in a wash potentially used by Amargosa 
toads. They further state that BLM usually does not enforce OHV 
exclusion from riparian areas in Oasis Valley (CBD and PEER 2008, p. 
27).
    Finally, the petition claims that BLM failed to follow through with 
habitat projects (CBD and PEER 2008, pp. 20 and 25) and the CA/S has 
failed at protecting toad habitat and increasing toad populations (CBD 
and PEER 2008, p. 27).
    Water development may adversely affect areas occupied by Amargosa 
toad. The State of Nevada permits exemptions for up to 1,800 gallons 
per day for residential use, which may collectively result in a 
substantial volume of groundwater withdrawal. The structure of State 
water regulations and absence of sufficient data on groundwater and 
surface water to support development without affecting toad habitat 
constitutes a potential threat to the Amargosa toad. Further, the 
Service is unaware of a final master plan that guides community 
planning in concert with toad conservation. The Service acknowledges 
that activities and potential development on private lands within Oasis 
Valley are significant threats to the toad.
    Near the Crystal Spring exclosure, BLM has approved OHV events that 
occur over a 2-day period during the daytime when Amargosa toads are 
sheltering. The BLM imposes permit conditions to minimize impacts to 
the area. The Service is unaware of any information that indicates 
these events or casual OHV use are threats to the Amargosa toad or that 
BLM fails to enforce OHV exclusion from riparian areas. In 2008, BLM 
chose an alternate route away from toad habitat for OHV events near 
Crystal Spring.
    Following a recent review of the CA/S, the ATWG concluded that 
implementation of the CA/S was an overall success. While some projects 
have not been completed, a number of important activities not 
identified in the CA/S have been conducted. The updated CA/S will 
include information on all accomplishments that benefit the toad. The 
petition asserts that several habitat enhancement projects proposed in 
the CA/S (CBD and PEER 2008, p. 20) were not completed, but these 
projects will be revisited in the upcoming review of CA/S.
    In summary, we find that the information provided in the petition, 
as well as information in our files, does present substantial 
scientific or commercial information indicating that listing the 
Amargosa toad may be warranted due to the inadequacy of the existing 
regulatory mechanisms, particularly State regulations that allow for 
residential groundwater use up to 1,800 gallons per day without the 
need for a permit and the lack of a final master plan for the Oasis 
Valley.

Factor E.

Other Natural or Manmade Factors Affecting the Species' Continued 
Existence

    The petitioners assert that the Amargosa toad is particularly 
vulnerable to extinction due to its exceedingly small range and small 
population size; most of its range has been impacted by humans 
(Simandle 2006, p. 14; Petition, pp. 16 and 29), and small populations 
are particularly vulnerable to genetic drift. Information in our files 
also suggests that the historical and current range of the Amargosa 
toad is small, i.e., approximately 10 miles (16 km) long consisting of 
8,440 ac (3,416 ha) centered on the Amargosa River and including 
movement corridors among adjacent spring sites and the river. Small 
population size and range, compounded by threats under Factor A, could 
threaten the Amargosa toad. Therefore, we find that the information in 
the petition and in our files presents substantial information that 
small range and population size may be an important threat to the 
Amargosa toad when combined with potential threats from development 
identified in Factor A.
    The petition states that species found in few locations, such as 
the Amargosa toad, are susceptible to stochastic events such as fire or 
floods (CBD and PEER 2008, p. 22). Controlled burns conducted on 
Torrance Ranch in 2008 were successful at reducing vegetation and 
improving toad habitat; toad reproduction was documented immediately 
following the burn (ATWG 2008, p. 1). Flood events are a natural 
disturbance and may benefit the Amargosa toad through periodic habitat 
disturbances. We will further investigate whether susceptibility to 
stochastic events is a potential threat to the toad during our status 
review.
    Radiation poisoning through groundwater contamination (from atomic 
testing on the Nevada Test Site) was also cited by the petitioners (CBD 
and PEER 2008, p. 21). The petitioners also assert that pollution of 
unknown levels on private land is a threat to the Amargosa toad (CBD 
and PEER 2008, p. 25). No information on groundwater connections or the 
types, amounts, infiltration speed, or locations of pollution was 
provided in the petition or exists in our files to support this claim 
as an important threat to the Amargosa toad. However, we will further 
investigate whether radiation poisoning through groundwater 
contamination is a potential threat to the toad during our status 
review.
    Environmental factors, including global warming, were identified by 
the petitioners as factors that could decrease habitat for the Amargosa 
toad through drought. The petitioners also mentioned increased UV-B 
radiation, which could weaken the Amargosa toad's immune system and 
result in mortality from disease (CBD and PEER 2008, p. 22). As 
acknowledged in the petition (CBD and PEER 2008, p. 23), disease has 
not been observed in Amargosa toads, and no field observations of 
Amargosa toad mortalities suggesting disease have been reported.
    We acknowledged in Factor A that management of water resources to 
meet the needs of the Amargosa toad is important for Amargosa toad 
conservation. Environmental changes due to climate change, including 
drought, could exacerbate the threats under Factor A. Therefore, we 
find that the information in the petition and in our files presents 
substantial information to indicate environmental changes due to 
climate change could exacerbate threats under Factor A and combine to 
threaten the Amargosa toad.

[[Page 46557]]

    Finally, the petitioners claim that introduced, invasive trees have 
become established along stretches of the Amargosa River and springs, 
which may reduce prey and microhabitat available for the Amargosa toad 
(CBD and PEER 2008, pp. 24 and 26). Since the CA/S was signed in 2000, 
removal of invasive trees, tamarisk (Tamarix ramosissima) and Russian 
olive (Elaeagnus angustifolia) has been ongoing and successful as a 
joint effort involving State, Federal, and private landowners. Amargosa 
toads are known to use areas underneath tamarisk and Russian olive 
trees for feeding and sheltering. Tamarisk and Russian olive removal 
efforts generally include replacement with native riparian species that 
will provide the same function. We will further investigate whether 
invasive trees are a potential threat to the toad during our status 
review.
    In summary, we find that the information provided in the petition 
and in our files presents substantial scientific or commercial 
information indicating that listing the Amargosa toad may be warranted 
due to threats from other natural or manmade factors. These factors, 
particularly small populations, small range size, and environmental 
changes due to climate change, could exacerbate threats identified 
under Factor A.

Finding

    We have reviewed the petition and the literature cited in the 
petition, and evaluated the information to determine whether the 
sources cited support the claims made in the petition. We also reviewed 
information that was readily available in our files. Based on our 
evaluation of the information provided in the petition, and information 
in our files, we find that the petition presents substantial scientific 
information indicating that listing the Amargosa toad may be warranted.
    Our process for making this 90-day finding under section 4(b)(3)(A) 
of the Act is limited to a determination of whether the information in 
the petition presents ``substantial scientific or commercial 
information,'' which is interpreted in our regulations as ``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)). 
Section 4(a) of the Act states the Secretary shall, by regulation 
promulgated in accordance with subsection (b) of the Act, determine 
whether any species is an endangered species or a threatened species 
because of any of the five listing factors. Furthermore, regulations at 
50 CFR 424.11(c) state a species shall be listed or reclassified if the 
Secretary determines, on the basis of the best scientific and 
commercial data available after conducting a review of the species' 
status, that the species is endangered or threatened because of any one 
or a combination of the five listing factors.
    As described in our Five-Factor Evaluation above, the petitioners 
presented substantial information indicating that the Amargosa toad may 
be threatened throughout its entire range due to four of the five 
listing factors described in the Act. Therefore, based on our 
determination that the petitioned action may be warranted due to 
substantial information presented under Factors A, C, D and E, we are 
initiating a status review to determine whether listing the Amargosa 
toad under the Act is warranted. We will address any other potential 
threats during our status review. To ensure that the status review is 
comprehensive, we are soliciting scientific and commercial information 
regarding the Amargosa toad relevant to all five listing factors.
    The ``substantial information'' standard for a 90-day finding 
differs from the Act's ``best scientific and commercial data'' standard 
that applies to a 12-month finding after a status review to determine 
whether a petitioned action is warranted. A 90-day finding is not a 
status assessment of the species and does not constitute a status 
review under the Act. Our final determination as to whether a 
petitioned action is warranted is not made until we have completed a 
thorough status review of the species, which is conducted following a 
positive 90-day finding. Because the Act's standards for 90-day and 12-
month findings are different, as described above, a positive 90-day 
finding does not mean that the 12-month finding also will be positive.

References Cited

    A complete list of references cited is available on the Internet at 
https://www.regulations.gov and upon request from the Nevada Fish and 
Wildlife Office, Las Vegas, Nevada (see FOR FURTHER INFORMATION 
CONTACT).

Author

    The primary authors of this notice are the staff members of the 
Nevada Fish and Wildlife 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: August 26, 2009.
Daniel M. Ashe,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E9-21762 Filed 9-9- 09; 8:45 am]
BILLING CODE 4310-55-S