[Federal Register Volume 77, Number 71 (Thursday, April 12, 2012)]
[Proposed Rules]
[Pages 21920-21936]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-8806]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R6-ES-2012-0003; 4500030113]
Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition To List the Eastern or Southern Rocky Mountain Population of
the Boreal Toad as an Endangered or Threatened Distinct Population
Segment
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of petition finding and initiation of status review.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding on a petition to list either the Eastern population or
the Southern Rocky Mountain (SRM) population of the boreal toad
(Anaxyrus boreas boreas) as a distinct population segment (DPS) that is
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 the Eastern population of the
boreal toad as a DPS may be warranted. We did not find substantial
information that listing the SRM population of the boreal toad as a DPS
may be warranted. Therefore, with the publication of this notice, we
are initiating a review of the status of the Eastern population to
determine if listing it as a DPS is warranted. To ensure that this
status review is comprehensive, we are requesting scientific and
commercial data and other information regarding the potential DPS.
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 the Act.
DATES: To allow us adequate time to conduct this review, we request
that we receive information on or before June 11, 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 June 11, 2012, you must submit information directly to
the Field Office (see FOR FURTHER INFORMATION CONTACT section below).
Please note that we might not be able to address or incorporate
information that we receive after the above requested date.
[[Page 21921]]
ADDRESSES: You may submit information by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Enter Keyword or ID box, enter Docket No.
FWS-R6-ES-2012-0003, which is the docket number for this action. Then
click on the Search button. You may submit a comment by clicking on
``Send a Comment or Submission.''
(2) By hard copy: Submit by U.S. mail or hand-delivery to: Public
Comments Processing, Attn: FWS-R6-ES-2012-0003; 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 e-mail or faxes. We will post all information we
receive on http://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: Western Colorado Supervisor, Western
Colorado Ecological Services Office, Grand Junction, CO; by telephone
at 970-243-2778; or by facsimile at 970-245-6933. 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 the
Eastern population of the boreal toad from governmental agencies,
Native American tribes, the scientific community, industry, and any
other interested parties. We seek information on:
(1) The species' biology, range, and population trends, including:
(a) Habitat requirements for feeding, breeding, and sheltering;
(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
determination for a species under section 4(a) of the 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 the Eastern
population of the boreal toad 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 also 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 species;
(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
species 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 species 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 http://www.regulations.gov, your entire submission--
including any personal identifying information--will be posted on the
Web site. 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 http://www.regulations.gov.
Information and supporting documentation that we received and used
in preparing this finding is available for you to review at http://www.regulations.gov, or by appointment, during normal business hours,
at the U.S. Fish and Wildlife Service, Western Colorado Ecological
Services 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.
Petition History
On May 25, 2011, we received a petition of the same date from the
Center for Biological Diversity, the Center for Native Ecosystems, and
the Biodiversity Conservation Alliance, requesting that either the
Eastern or SRM population of the boreal toad be listed as an endangered
or threatened DPS and that critical habitat be designated under the
Act. The petitioners also requested that if boreal toads in either the
Eastern or SRM population are designated as separate species during
consideration of the petition (based on recent and ongoing genetic
studies) that both species be listed under the Act. We note the request
to list either population as a DPS, or, if the two populations are
[[Page 21922]]
found to be separate species, to list each as a separate species;
however, there are currently no scientific papers calling for species
designations for these two populations. Consequently, this 90-day
finding examines only the possibility of listing the Eastern or SRM
population as a DPS or two DPSs, and not the species question.
The petitioners included the requisite information in the petition,
as required at 50 CFR 424.14(a). In a June 23, 2011, letter to the
petitioners, we responded that we reviewed the information presented in
the petition and determined that issuing an emergency regulation
temporarily listing the species as endangered under section 4(b)(7) of
the Act was not warranted. We also stated that we would initiate
response to the petition in Fiscal Year 2011 and would finalize a
response in Fiscal Year 2012 (approximately March 2012). This finding
addresses the petition.
Previous Federal Action(s)
On September 30, 1993, the Service received a petition from the
Biodiversity Legal Foundation of Boulder, Colorado, and Dr. Peter
Hovingh, a researcher at the University of Utah, Salt Lake City, Utah.
The petitioners requested that the Service list the SRM population of
the ``western boreal toad'' (a common name sometimes used in the past
for Anaxyrus boreas boreas) as endangered throughout its range in
northern New Mexico, Colorado, and southeastern Wyoming. The
petitioners also requested that the Service designate critical habitat.
We published a notice of a 90-day finding for the petition in the
Federal Register on July 22, 1994 (59 FR 37439), indicating that the
petition and other readily available scientific and commercial
information presented substantial information that the petitioned
action may be warranted.
On March 23, 1995, the Service announced a 12-month finding that
listing the SRM population of the boreal toad as an endangered DPS was
warranted but precluded by other higher priority actions (60 FR 15281).
At that time, a listing priority number of 3 was assigned. When we find
that a species is warranted but precluded for listing, we refer to it
as a candidate species. Section 4(b)(3)(B) of the Act directs that when
we make a ``warranted but precluded'' finding on a petition, we are to
treat the petition as being one that is resubmitted annually on the
date of the finding; thus, the Act requires us to reassess the
petitioned actions and to publish a finding on the resubmitted petition
on an annual basis. Several resubmitted candidate assessments for the
boreal toad were completed. The most recent assessment was published in
the Federal Register on May 11, 2005 (70 FR 24870).
On October 7, 2002, as part of an agreement regarding multiple
species, the U.S. Department of the Interior reached an out-of-court
settlement with several conservation organizations and agreed to make a
final determination for listing the SRM population of the boreal toad
by no later than September 30, 2005. In the 2005 Annual Notice of
Findings on Resubmitted Petitions, we noted that a determination for
the boreal toad would be funded in Fiscal Year 2005 (70 FR 24870). On
September 29, 2005, we reached a determination in the revised 12-month
Finding that the SRM population of the boreal toad did not warrant
listing because it was not a listable entity according to the DPS
criteria and, therefore, should be withdrawn from the candidate list
(70 FR 56880). When the boreal toad was put on the candidate list in
1995, the DPS policy did not yet exist, so current criteria were not
used to determine whether the toad was a listable entity. The
combination of using the DPS criteria developed in1996 and genetic and
other information available during development of the 2005 finding led
to determinations that the SRM population of the boreal toad was
discrete based on DPS discreteness criteria but was not significant
based on DPS significance criteria. Therefore, it was not considered a
listable entity.
On September 2, 2008, we received a notice of intent to sue from
the Center for Biological Diversity (dated August 28, 2008) for
violations of the Act (i.e., failure to issue a proposed rule in 2005
or subsequently list the toad), but a lawsuit never followed.
Species Information
Taxonomy
The Anaxyrus boreas (formerly Bufo boreas) group of toads, of which
the boreal toad is a subspecies, are amphibians that occur throughout
much of the western United States. The species was first described from
specimens collected on the Columbia River (Washington or Oregon) and
Puget Sound (Washington) by Baird and Girard (1852). The genus for the
boreal toad was revised from Bufo to Anaxyrus in 2006 (Frost et al.
2006, pp. 10, 213, 218, 222, 281, 329, 350, 363), and the Service
accepts this revision.
Two subspecies of the boreal toad have been recognized for many
years, the boreal toad (A. b. boreas, the subject of this finding) and
the California toad (A. b. halophilus) (Camp 1917, p. 116). Other
authors recognize up to four subspecies, with the Amargosa toad (A.
nelsoni or A. b. nelsoni) and black toad (A. exsul) or (A. b. exsul)
being the other two potential subspecies (Crother 2000 (2001), p. 7;
2008, pp. 2-4; Stebbins 2003, pp. 208-209, map 32). The Yosemite toad
(A. canorus) also is considered to be a distinct but closely related
species (Stebbins 2003, p. 210-211). All of the toad species and
subspecies mentioned above are considered by Goebel et al. (2009, pp.
221, 223) and Switzer et al. (2009, pp. 25-26) to comprise the A.
boreas group. Deoxyribonucleic acid (DNA) analyses by these two sets of
authors suggest that a taxonomic change to the A. boreas group could be
appropriate.
Two different studies analyzing mitochondrial DNA (mtDNA) from
boreal toads and other closely related species and subspecies conclude
that toads within the SRM population (southeastern Wyoming, Colorado,
and New Mexico) and southwestern Wyoming, southeastern Idaho,
northeastern Nevada, and Utah form a population of genetically similar
toads termed the Eastern Major Clade (Goebel et al. 2009, p. 210, fig.
1) or Clade 3-1 (Switzer et al. 2009, p. 8). The combination of these
two clades (populations of genetically similar toads), the Eastern
Major Clade and Clade 3-1, primarily form the Eastern population (see
the map in this notice). Switzer et al. (2009, fig. 3) also identify a
smaller clade (named Clade BO by Switzer et al.) based on a distinct
haplotype in southern Utah that constitutes a small part of the Eastern
population (see the map in this Federal Register notice). Also examined
within this finding are boreal toads found within the part of the
Northwest Major Clade that overlaps with the Eastern Major Clade
(Goebel 2003, p. 2; Goebel et al. 2009, p. 210, fig. 1). This overlap
is further supported by Switzer et al. (2009, fig. 3), who found that
the area they designated as Clade 3-2 overlaps with Clade 3-1 (see the
map in this notice). Clade 3-2 is a weakly supported clade that, in
combination with Clade 3-3 and sister Clade 3-4, constitutes the larger
Clade 4-1 discussed in Switzer et al. (2009, pp. 9-10, fig. 2).
The Northwest Major Clade extends from western Wyoming and
northwestern Utah over to west-central California and up to
southeastern Alaska, including ranges of both the boreal toad and the
California toad (Goebel et al. 2009, p. 215). The Eastern Major Clade
extends from central Colorado to northeastern Nevada, and from southern
Wyoming to northern New Mexico and Arizona (see the map
[[Page 21923]]
in this notice). All of the toads within the Eastern Major Clade and
overlap area of the Northwest Major Clade (or Clades 3-1 and 3-2) are
considered to be boreal toads (Goebel et al. 2009, p. 215; Switzer et
al. 2009, p. 3) (see the map in this notice).
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As illustrated in the map in this notice, the combination of the
outermost extent of both 2009 genetic articles' clade boundaries
primarily form the boundaries of the Eastern population. Two exceptions
occur in west-central Utah and eastern Nevada, where the Eastern
population boundary extends beyond the clade boundaries (see map). The
petitioners based the Eastern population boundaries on gross range maps
drawn by the International Union for Conservation of Nature, creating
the two exceptions. Reduction in size of the Eastern population from
clade boundaries also occurs in Arizona, northwestern New Mexico, and
the other States, based on lack of habitat and no records of boreal
toads ever occurring in the excluded areas (see map).
Portions of Goebel et al.'s (2009, p. 210, fig. 1) Northwest Major
Clade and Switzer et al.'s (2009, fig. 3) Clade 3-2 are illustrated in
the map in this notice, and discussed in the ``Evaluation of Listable
Entities'' section below, because of their geographic and genetic
overlap with the Eastern Major Clade and Clade 3-1 and their necessary
consideration in making a determination on whether the Eastern
population is a listable entity. The other petitioned entity, the SRM
population of the boreal toad, is a subset of the Eastern population
(see map).
Biology
Boreal toads may reach a length (snout to vent) of 12.7 centimeters
(5 inches) (Hammerson 1999, p. 90; Stebbins 2003, p. 208). They possess
warty skin, oval parotoid glands, and often have a distinctive light
mid-dorsal stripe. During the breeding season, males develop a dark
patch on the inner surface of the innermost digit. Unlike many other
toad species, the boreal toad has no vocal sac and, therefore, produces
no mating call (Hammerson 1999, p. 90). Tadpoles are black or dark
brown.
Boreal toads in the SRM population typically occupy habitat at
elevations between 2,440 meters (m) (8,000 feet (ft)) and 3,350 m
(11,000 ft) (Loeffler 2001, p. 6). However, within the Eastern
population, they have been recorded as low as 1,570 m (5,150 ft) and as
high as 3,661 m (12,000 ft) (Livo and Yeakley 1997, p. 143; Thompson et
al. 2004, p. 256; Hogrefe et al. 2005, p. 7). Boreal toads occurring
further north and west from the SRM population occupy lower elevations
and are found down to sea level on the Pacific coast (Stebbins 2003, p.
209). At higher elevations, adult boreal toads emerge from winter
refugia when snowmelt has cleared an opening from their burrows and
daily temperatures remain above freezing (Campbell 1970a, pp. 22, 99;
Campbell 1970b, p. 281). Breeding can occur from late January to July,
depending on latitude, elevation, and local conditions (Stebbins 2003,
p. 209). Breeding occurs during a 2- to 4-week period from mid-May to
mid-June at lower elevations, and as late as mid-July at higher
elevations in the SRM population (Hammerson 1999, p. 96). Suitable
breeding sites are large bodies of water or small pools, beaver ponds,
glacial kettle ponds, roadside ditches, human-made ponds, and slow-
moving streams (Campbell 1970a, pp. 24-25; Hammerson 1999, p. 95).
Boreal toads have been observed to lay up to 16,500 eggs (Campbell
1970a, p. 24), and, in Colorado they have been observed laying up to
10,900 eggs (Hammerson 1999, p. 96), with an overall mean clutch size
of 6,661 eggs (Carey et al. 2005, p. 224). The eggs are black and are
deposited in long double-layer jelly strings, with one to three rows of
eggs (Hammerson 1999, p. 90). Eggs hatch 1 to 2 weeks after being laid.
Egg and tadpole development is temperature-dependent, and reproductive
efforts may fail if tadpoles do not have sufficient time to
metamorphose before the onset of winter. Persistent, shallow bodies of
water are critical to breeding success, and if the breeding site dries
before metamorphosis is complete, desiccation of the tadpoles or eggs
will occur. Tadpoles typically metamorphose by late July to late
August, but at higher elevations metamorphosis may not be complete
until late September (Loeffler 2001, p. 7). Recently metamorphosed
toadlets (metamorphs) aggregate within a few meters of the water and
move into nearby moist habitats later in summer.
After mating, adults often disperse to upland, terrestrial
habitats, where they are mostly active during the day in early and late
summer (Mullally 1958, entire; Campbell 1970a, pp. 84-86; Carey 1978,
pp. 203, 206, 211), foraging primarily on ants, beetles, spiders, and
other invertebrates (Schonberger 1945, p. 121; Campbell 1970a, p. 69-
71). Late in the summer the toads will expand their home ranges,
generally in the direction of wintering habitats, which include
cavities among streamside boulders, ground squirrel burrows, and beaver
lodges and dams (Campbell 1970a, pp. 50, 87; Hammerson 1999, p. 94).
Survival of embryos from laying to hatching is normally high, but
catastrophic mortality has been observed (Blaustein and Olson 1991,
entire). Survival of tadpoles and juveniles is low, with predation and
adverse environmental conditions primarily responsible for mortality at
these life stages (Campbell 1970a, p. 61). Between 95 and 99 percent of
juveniles die before reaching their second year of life (Samollow 1980,
p. 33). The minimum age of breeding boreal toads is about 4 years in
males and 6 years in females (Hammerson 1999, p. 97). Females may skip
1 to 3 years between breeding attempts, and individuals may live
approximately 11 or 12 years (Olson 1991, pp. 7, 14).
Distribution, Abundance, and Trends
The range of the boreal toad subspecies (Anaxyrus boreas boreas)
extends from coastal Alaska south and east through the Yukon Territory,
the extreme southwest corner of the Northwest Territory, British
Columbia, western Alberta, Washington, Oregon, northern California,
northern Nevada, Idaho, western Montana, western and southeastern
Wyoming, central and northern Utah, central to western Colorado, and
extreme north-central New Mexico (Stebbins 2003, map 32; Goebel et al.
2009, p 210). No records of the boreal toad exist from Arizona or
northwestern New Mexico, and, therefore, we do not consider the range
of the boreal toad to include Arizona or northwestern New Mexico.
The range of the SRM population includes southeastern Wyoming
through the mountainous region of central to west-central Colorado, and
into extreme north-central New Mexico. The range of the Eastern
population encompasses the SRM population and also includes
southwestern Wyoming, southeastern Idaho, northeastern Nevada, and Utah
(Goebel et al. 2009, p. 210; Switzer et al. 2009, p. 8, figure 3;
Greenwald et al. 2011, pp. 17, 56-72) (see the map in this notice).
SRM Population
Southeastern Wyoming
In southeastern Wyoming, the boreal toad was once widespread and
numerous in the Medicine Bow, Pole, Snowy, and Sierra Madre Mountain
Ranges (Baxter and Stone 1985, p. 31; Keinath and Bennett 2000, p. 4).
Declines in populations were documented in southeastern Wyoming from
1986 through 1988 (Corn et al. 1989, pp. iv, 26), and the subspecies is
now rare in southeastern Wyoming (Keinath and Bennett 2000, p. 4;
Jackson 2008, p. 4). Distribution, abundance, and trends of SRM toads
are based on field monitoring from 1997 through 2011, but the latest
written report ends with the 2007 field season (Jackson
[[Page 21925]]
2008, entire). In 2003, toads were observed in only seven southeastern
Wyoming locations (in Albany and Carbon Counties). Only one breeding
population is known to occur in southeastern Wyoming (Jackson 2008, pp.
91-92; Colorado Division of Wildlife 2010, p. 1). However, this
population does not meet the population viability criteria established
in the SRM conservation plan that was written by the State-led Boreal
Toad Recovery Team (composition of Team described in Factor D)
(Loeffler 2001, p. 17-18). The viability criteria specify the number of
adults required at a breeding site, the frequency of breeding activity,
and the amount of egg production and recruitment needed to maintain a
viable population. The criteria also specify that a viable population
must face no known significant and imminent threats to its habitat,
health, or environmental conditions.
Colorado
In Colorado, the boreal toad was historically known to occur in 25
counties, and was common throughout the higher elevations (Burger and
Bragg 1947, pp. 61-62; Smith et al. 1965, p. 5; Keinath and McGee 2005,
p. 22), except for the Sangre de Cristo Mountains, Wet Mountains, and
Pikes Peak region (Hammerson 1999, p. 90). Disappearances of 11
populations in the West Elk Mountains were documented between 1974 and
1982 (Carey 1993, pp. 357-358). Surveys of 59 historically occupied
localities in Colorado between 1986 and 1988 failed to find individuals
in 83 percent (49 locations) of the sites (Corn et al. 1989, p. iv).
Surveys conducted in 1989 (249 locations) and 1991 (377 locations) in
suitable habitat and historical locations resulted in finding boreal
toads at 2 and 1 location, respectively (Hammerson 1989, pp. 41, 46,
50, 52, 53; Hammerson 1992, pp. 2, 142). The number of known breeding
populations increased from 1996 to 2007, from the high teens to mid-
40s; however, the number of individuals in some breeding populations
have declined significantly from large numbers in the late 1990s or
early 2000s to relatively few individuals as of 2007. Many more
breeding sites and breeding populations have had very few toads
observed since their initial discovery (Jackson 2008, pp. 12-91, 94).
Despite knowledge of increased numbers of locations of boreal toads,
the Boreal Toad Recovery Team identified only one population meeting
the SRM conservation plan definition of viable in 2006 and 2007, versus
a high of six populations in 1999 (Loeffler 2001, p. 17-18; Jackson
2008, p. 11). The lower number of viable populations is primarily due
to detection of chytrid fungus (Batrachochytrium dendrobatidis),
hereafter abbreviated ``Bd,'' a threat suspected in decline of boreal
toad numbers and distribution (Jackson 2008, pp. 6, 10). The above
information suggests boreal toad populations are declining in Colorado.
New Mexico
The boreal toad was known to occur in three Rio Arriba County, New
Mexico, localities: Lagunitas, Canjilon, and Trout Lakes (Campbell and
Degenhardt 1971, entire; Jones 1978, p. 3; New Mexico Department of
Game and Fish (NMDGF) 1988, p. 1; Degenhardt et al. 1996, p. 49).
Declines were first documented in New Mexico in the mid-1980s (Woodward
and Mitchell 1985, p. 5; Carey 1987, pp. 1, 3). Surveys in 1993
revealed no populations at the three previously known locations (Stuart
and Painter 1994, p. 115). No boreal toads were observed during surveys
of the Trout Lakes and Lagunitas areas of New Mexico in 2004 (Jackson
2005, p. 41). Consequently, in 2008 a repatriation program was started
at Trout Lakes with over 4,000 Colorado-reared tadpoles being released
(NMDGF 2008, p. 2; USFWS 2009, p. 3). In 2009, over 3,400 tadpoles were
released at Trout Lakes (NMDGF 2010, p. 4-5; USFWS 2010, p. 3). In
2009, only seven boreal toads from the 2008 release were recaptured
(NMDGF 2010, p. 3).
In summary, based on currently available data, the distribution and
abundance of boreal toads in the SRM population appears to be
declining.
Eastern Population, Excluding the SRM Portion of the Population (see
above)
Southwestern Wyoming
Relatively recent records (1993-2003) and historical records (pre-
1993) of boreal toad locations were compiled for southwestern Wyoming
(McGee and Keinath 2004, pp. 65-66). Historically, boreal toads
occurred in Uinta and Lincoln Counties in the southwestern corner and
west-central edge of Wyoming. One (nonbreeding) record from far eastern
Lincoln County was recorded in the 1993-2003 time period. Other recent
records in the region are from Sublette County bordering the eastern
side of Lincoln County. Juvenile or recently metamorphosed toads and
tadpoles were collected in Sublette County, Wyoming, for genetic
analysis. The most southerly of the three toad samples was grouped with
the Eastern population by Goebel (2003, p. 7). We do not have more
recent distribution or status information in our files for southwestern
Wyoming.
Southeastern Idaho
Two genetic sample sites in southeastern Idaho occur within the
Eastern population (Switzer et al. 2009, fig. 3 and table 8). We do not
currently have additional information on boreal toad distribution or
status in southeastern Idaho.
Northeastern Nevada
One boreal toad genetic sample has been collected in northeastern
Nevada (Goebel et al. 2009, pp. 210 and 212). We currently have no
additional information on the distribution or status of boreal toads in
northeastern Nevada.
Utah
The petition states that boreal toads are largely distributed
throughout most of their historical range in Utah, which includes
northern and central Utah (referencing Thompson et al. 2004, entire).
Toads were considered to be irregularly distributed, and not all
historical areas were occupied at the time of the Utah Boreal Toad
Conservation Plan's development (Hogrefe et al. 2005, p. 5). The Utah
Conservation Plan states that between 1995 and 2004, toads were
recorded at a minimum of 102 localities (Hogrefe et al. 2005, p. 5),
and eight populations were considered viable (Hogrefe et al. 2005, p.
1). Ten populations in 2009 were considered viable according to the
definition in the Utah Conservation Plan (Utah Division of Wildlife
Resources (UDWR) 2010, pp. I-16, I-17, II-10, III-5, IV-12).
In summary, based on currently available data, the number of viable
populations appears stable in Utah, but little information exists to
evaluate the current distribution or trend in abundance in the Eastern
population outside of the boundaries of the SRM population.
Evaluation of Listable Entities
Under section 3(16) of the Act, we may consider for listing any
species, including subspecies, of fish, wildlife, or plants, or any DPS
of vertebrate fish or wildlife that interbreeds when mature (16 U.S.C.
1532(16)). Such entities are considered eligible for listing under the
Act (and, therefore, are referred to as listable entities) if we
determine that they meet the definition of an endangered or threatened
species. The petitioners have requested that either the SRM population
of the boreal toad or the Eastern population of the boreal toad be
considered a DPS and listed as endangered or threatened under the Act.
[[Page 21926]]
Distinct Vertebrate Population Segment
In determining whether an entity constitutes a DPS, and is
therefore listable under the Act, we follow the Policy Regarding the
Recognition of Distinct Vertebrate Population Segments Under the
Endangered Species Act (DPS Policy) (61 FR 4722; February 7, 1996).
Under our DPS Policy, we analyze three elements prior to listing a
possible DPS: (1) The discreteness of the population segment in
relation to the remainder of the taxon; (2) the significance of the
population segment to the taxon to which it belongs; and (3) the
population segment's conservation status in relation to the Act's
standards for listing (e.g., is the population segment, when treated as
if it were a species, endangered or threatened?) (61 FR 4722). This
finding considers whether the petitioned SRM population or Eastern
population of the boreal toad may be a DPS.
Discreteness
Under our DPS Policy, a population segment of a vertebrate species
may be considered discrete if it satisfies either one of the following
conditions: (1) It is markedly separated from other populations of the
same taxon as a consequence of physical, physiological, ecological, or
behavioral factors (quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation); or (2) it is
delimited by international governmental boundaries within which
significant differences in control of exploitation, management of
habitat, conservation status, or regulatory mechanisms exist (61 FR
4722).
Significance
Under our DPS Policy, in addition to our consideration that a
population segment is discrete, we consider its biological and
ecological significance to the taxon to which it belongs. This
consideration may include, but is not limited to, the following:
(1) Evidence of the persistence of the discrete population segment
in an ecological setting that is unusual or unique for the taxon;
(2) Evidence that loss of the discrete population segment would
result in a significant gap in the range of a taxon;
(3) Evidence that the discrete population segment represents the
only surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside its historical range; or
(4) Evidence that the discrete population segment differs markedly
from other populations of the species in its genetic characteristics
(61 FR 4722).
Discreteness Information Provided in the Petition
The petition cites two genetic studies (Goebel et al. 2009, entire;
Switzer et al. 2009, entire) that the petitioners believe support
either that (1) the Eastern population, which would include the SRM
population, is markedly separate from other boreal toad populations
because of genetic differences and geographic separation, or (2) the
SRM population is markedly separate from the rest of the Eastern
population, as well as all other boreal toad populations, due to
geographic separation. The petitioners recognize there may be overlap
in genetics and geography between the Eastern and SRM populations, as
well as with other populations within the range of the species, but
they believe that the level of overlap is within the bounds allowed by
the DPS policy in that the DPS policy does not ``require absolute
reproductive isolation as a prerequisite to recognizing a distinct
population segment'' (61 FR 4722).
Significance Information Provided in the Petition
The petition states that both the Eastern population and SRM
population occur in an unusual or unique ecological setting. The
petition also states that a significant gap in the range could occur if
boreal toads are extirpated from either the Eastern population (a 20
percent (or 161,422 square miles) loss of the species' range in the
conterminous United States) or SRM population (a 5 percent (or 38,894
square miles) loss of the species' range in the conterminous United
States). Furthermore, the petition states that the Eastern population
is significant based on Goebel et al. (2009, entire) and Switzer et al.
(2009, entire). The petition further states that evidence shows that
the SRM population may be significant based on the potential for the
SRM population to be its own evolutionary unit as evidenced by
geographic separation and greater diversity than currently recognized
species (Goebel et al. 2009, pp. 213, 221).
Evaluation of Information Provided in the Petition and Available in
Service Files on Discreteness of the SRM Population
Based on evidence of feasible dispersal distances, the SRM
population is likely geographically (physically) separated from other
populations of the boreal toad, including the western portion of the
Eastern population (Keinath and McGee 2005, p. 16, fig. 7 and pp. 26-
27) (see the map in this notice). The greatest recorded distance of
movement for a boreal toad in the southern Rocky Mountains is 8
kilometers (km) (5 miles (mi)) (Lambert 2003, p. 88). The map in this
notice illustrates the gross range of the western part of the Eastern
population and the SRM population. We used complete hydrologic units to
develop the eastern boundary of the western part of the Eastern
population. The petition maps did not use complete hydrologic units,
particularly in northeastern Utah, but rather cut them off at State
boundaries. The Red Desert separates these two portions of the Eastern
population in Wyoming by about 126 km (78 mi), and arid habitat in
western Colorado and eastern Utah create separation of at least 84 km
(52 mi). However, boreal toads are not known to actually occupy the
outer extent (lower elevations) of the gross hydrologic units in the
map in this notice. Maps in the petition can be referred to in order to
see hydrologic units known to be occupied by boreal toads (Greenwald et
al. 2011, pp. 56-72). Looking at these hydrologic unit of occurrences,
and based on relatively current ranges described in Keinath and McGee
(2005, p. 16, fig. 7), approximately 210 km (130 mi) of separation
occurs in Wyoming. At least 200 km (125 mi) of separation occurs in
eastern Utah and western Colorado (Greenwald et al. 2011, pp. 9, 56-
72). Therefore, the large size and arid, inhospitable habitat of the
Red Desert and arid lands to the south in Colorado and Utah likely
create a geographic barrier to migrating toads.
Mitochondrial DNA analysis indicates that the SRM population is
part of a more widespread evolutionary lineage that includes boreal
toad populations from Utah, northeastern Nevada, southeastern Idaho,
and southwestern Wyoming (Goebel et al. 2009; Switzer et al. 2009).
However, since mtDNA evolves slowly, taxonomic separation based solely
on mtDNA may not provide clear taxonomic distinctions. For example, a
single haplotype from boreal toads in the Uinta Mountains of Utah also
occurs in boreal toads in the SRM population (Goebel et al. 2009, p.
221). Discovery of this haplotype common to both areas led to the
combination of the SRM population and the Uinta Mountain site as a
minor clade--that clade is named the Eastern Rocky Mountain Minor Clade
(Goebel et al. 2009, p. 217, figure 4). However, due to the long
distance separating the sites, the occurrence of this haplotype in both
areas may be a result of incomplete lineage sorting commonly found in
recently isolated groups (Goebel et al.
[[Page 21927]]
2009, p. 221). In other words, boreal toads from the Uinta Mountain
site and the SRM population may have interbred at one time thousands to
millions of years ago, but are not likely to have interbred since then,
and the similar haplotype detection is simply a feature of the slow
evolutionary changes that can occur in portions of mtDNA. These
statements lend support to the idea that the geographic separation of
the SRM population has eliminated genetic interbreeding and the SRM
population is discrete. However, further DNA (particularly nuclear DNA
(nDNA)) studies are needed to provide clarification on taxonomy, before
genetic evidence could be used to support genetic discreteness of the
SRM population.
Nonetheless, based on its current geographic separation from other
boreal toad populations, we believe there is substantial information to
indicate that the SRM population may meet the DPS Policy definition of
discreteness.
Evaluation of Information Provided in the Petition and Available in
Service Files on Discreteness for the Eastern Population (which
includes the SRM population)
As referenced above, two different studies analyzing mtDNA from
boreal toads and other closely related species and subspecies conclude
that toads within the SRM population and southwestern Wyoming,
southeastern Idaho, northeastern Nevada, and Utah form a population of
genetically similar toads termed the Eastern Major Clade (Goebel et al.
2009, p. 210, fig. 1) or Clade 3-1 (Switzer et al. 2009, p. 8, and fig.
3), which we refer to in this document as the Eastern population of the
boreal toad (see the map in this notice). Both studies acknowledge that
the Eastern population overlaps with areas identified as the
Northwestern Major Clade (Goebel et al. 2009, p. 210, fig. 1) or Clade
3-2 (Switzer et al. 2009, fig. 3) (see the map in this notice).
Therefore, absolute reproductive isolation may not currently be
occurring between the Eastern population and other populations of
boreal toads. However, studies suggest that the Eastern Major Clade and
the Northwestern Major Clade are sufficiently different that they may
represent different species (Goebel 2003 p. 7). There is a need to
examine additional nDNA further north in Wyoming, in the Yellowstone
area and surrounding regions, to determine if nDNA divergence parallels
mtDNA divergence in boreal toads (Goebel 2003, p. 8).
Through mtDNA analysis, Goebel (2003, pp. 8-9) found greater
differences between boreal toads in the Eastern Major Clade versus the
Northwest Major Clade than mtDNA differences found between the Canadian
toad (Bufo hemiophrys) and American toad (B. americanus), which are
considered to be two separate species. Goebel et al. (2009, p. 15)
provides further support for genetic differences, identifying the
Eastern and Northwest Major Clades of boreal toads as having different
haplotype groups. This mtDNA separation suggests the Eastern population
of boreal toads may be a distinct species (or subspecies) from toads in
the Northwest Major Clade or other taxonomic entities of boreal toads
to the north and west. Haplotypes found through mtDNA analysis and
microsatellite DNA analysis are differentiated enough between Clade 3-1
(corresponding to the Eastern population) and Clade 3-2 to the north
that Switzer et al. (2009, p. 8, 23, 25) hypothesized Clade 3-1 could
be its own taxonomic entity.
The petition states that the Snake River Plain in Idaho
geographically separates the boreal toad populations. Boreal toads
might not cross the Snake River Plain itself; however, based on genetic
samples, it does not appear that the Plain is a genetic barrier
(Switzer et al. 2009, fig 3). Genetic samples from Clade 3-2 (Switzer
et al. 2009, fig. 3) and the Northwest Major Clade (Goebel et al. 2009,
p. 210, fig. 1) occur north and south of the Plain, which suggests
boreal toad gene flow around the Snake River Plain. The petition
erroneously states that the Hell's Canyon portion of the Snake River
separates boreal toads along the Idaho-Wyoming border. Although the
upper end of the Snake River does occur on the Idaho-Wyoming border,
Hell's Canyon is on the Idaho-Oregon border.
The petition also states that gene flow may occur to the west of
the northeastern Nevada site where samples were obtained by Goebel et
al. (2009, pp. 210, 212). However, the petition cites Noles (2010,
entire), who reviewed and studied genetic and historical geologic
processes (phylogeography) to explain distribution of boreal toad
clades in Nevada. The study identifies some genetic sample sites and
clade names for boreal toads in Nevada and states that it is reasonable
to suspect that boreal toads in the Bonneville Basin are discernible
from boreal toads in the Relict Dace Basin and the Lahontan Basin
immediately to the west (Noles 2010, pp. 24, 50, 51). These statements
lend support to the idea that the western edge of the Bonneville Basin
is the northwesternmost extension of the Eastern population, as
asserted by the petition. However, limited boreal toad genetic sampling
in the Bonneville Basin, Relict Dace Basin, Lahontan Basin, and an
unnamed basin on the northern border of Nevada make the genetic overlap
issue unclear in western Utah, northern Nevada, southwestern Idaho, and
eastern Oregon (Noles 2010, pp. 12, 38, 39, 50, 51).
Based on genetic data, there appears to be a continuum of boreal
toad distribution from southeastern Idaho into western Wyoming and all
the way to Alaska, as well as a continuum from northwestern Utah,
northern Nevada, southwestern Idaho, and eastern Oregon all the way to
Alaska (Goebel et al. 2009, p. 210, 217; Switzer et al. 2009, figure
3). However, the DPS policy allows for some overlap of interbreeding
and states that animals do not ``require absolute reproductive
isolation as a prerequisite to recognizing a distinct population
segment'' and that ``recognized species * * * are known to sustain a
low frequency of interbreeding with related species'' (61 FR 4722).
Furthermore, as the DPS Policy explains, discreteness ``does not
require absolute separation of a DPS from other members of its species,
because this can rarely be demonstrated in nature for any population of
organisms. This standard [adopted by the DPS Policy] is believed to
allow entities recognized under the Act to be identified without
requiring an unreasonably rigid test of distinctness'' (61 FR 4722).
Consequently, based primarily on mtDNA genetic evidence and
phylogeographic evidence, we find that the petition and our files
contain substantial information that the Eastern population of the
boreal toad may be discrete, despite some genetic and geographic
overlap with other boreal toad populations. We will further examine
this information during the status review for the 12-month finding.
Evaluation of Information Provided in the Petition and Available in
Service Files on Significance for the SRM Population
Unusual or Unique Ecological Setting
The petition asserts that boreal toads in the SRM population could
be significant based on unusual or unique ecological settings as
described in a map of ecoregions (areas with common vegetation, soils,
geology, precipitation levels, hydrology, etc.) (U.S. Environmental
Protection Agency (EPA) 2011, entire). The petitioners assert that
ecoregions in the SRM population are distinct from ecoregions in the
Eastern population, as well as distinct from
[[Page 21928]]
ecoregions in other areas occupied by the boreal toad. For the purposes
of determining significance in a DPS analysis, we look at whether the
ecological settings occupied in the area under consideration are unique
or unusual to the taxon in question, not whether the setting is unique
from other settings. The petitioner did not provide substantial
information to indicate that the geographic area occupied by the SRM
population is unique or unusual for the boreal toad taxon, as required
by the DPS policy. Additionally, we found no information in our files
that these settings were unique to the SRM population of the boreal
toad.
The petition referenced a study that indicates that boreal toads
may occur at lower elevations in Utah than in the SRM population
(Hogrefe et al. 2005, p. 7). However, there is still overlap in
elevational range of occupied habitats between boreal toads in the SRM
population and in Utah; therefore, elevation does not appear to
differentiate a unique ecological setting for boreal toads in the SRM
population. Also, the petition notes that the ecoregions have varying
(but overlapping) levels of precipitation and vary in dominant
vegetation types, but again, specific habitats that boreal toads
actually occupy (for example, mesic subalpine habitats) appear similar
across all ecoregions. Consequently, there is not substantial evidence
in the petition or in our files to support unusual or unique ecological
settings as a significant factor in differentiating the SRM population
from the western part of the Eastern population or from other areas
throughout the range of the boreal toad.
Significant Gap in Range
The petition states the SRM population constitutes about 5 percent
(or 38,894 square miles) of the range in the conterminous United States
and that its loss could pose a significant gap in the range of the
boreal toad. This loss, which would occur at the southeastern edge of
the range, would create a gap in the range of the boreal toad in the
conterminous United States. However, we do not believe this gap would
be significant, due to the combination of the area being on the edge of
the range and covering a relatively small area. We do not believe there
is substantial information that the loss of SRM would be significant to
the taxon.
Marked Differences in Genetic Characteristics
The petition suggests that boreal toads in the SRM population are
significant under the DPS Policy because they comprise more diversity
than currently recognized species, such as in the Canadian toad and
American toad example used above by Goebel et al. (2009, p. 215).
However, in order to be considered significant under the DPS criteria,
it is not important how diverse the population is, but rather whether
that diversity (e.g., that of haplotypes) differs markedly from other
populations of boreal toads. Also, although Goebel et al.'s (2009, p.
221) statement about incomplete lineage sorting may prove accurate, we
do not find there is currently enough genetic data to support the
statement. Goebel et al. (2009, p. 15) conclude that the SRM population
shares haplotypes with boreal toads in the western part of the Eastern
Major Clade. Switzer et al. (2009, p. 26) also conclude that boreal
toads within the SRM population share haplotypes with boreal toads in
the western portion of Clade 3-1. In fact, both studies group boreal
toads in the SRM population genetically with other toads in the Eastern
population, concluding that they are part of a more widespread
evolutionary lineage. Consequently, we find that current genetic
analyses do not provide substantial information that the SRM population
may be significant, because the SRM population does not have markedly
different genes compared to the rest of the Eastern population.
Evaluation of Information Provided in the Petition and Available in
Service Files on Significance for the Eastern Population
Unusual or Unique Ecological Setting
The petition asserts that boreal toads in the Eastern population
could be significant based on unusual or unique ecological settings as
described in a map of ecoregions (EPA 2011, entire). They assert that
ecoregions in the Eastern population are distinct from other ecoregions
outside of the Eastern population. For the purposes of determining
significance in a DPS analysis, we look at whether the settings
occupied in the area under consideration are unique or unusual to the
taxon in question, not whether the setting is unique from other
settings. We do not agree with the petition's assertion that ecoregions
in the Eastern population are unique. Some areas within the range of
the taxon may in fact be unique because of elevation, precipitation
levels, and vegetative characteristics. However, we find that many of
the ecoregions, and areas actually occupied by the boreal toad within
the range of the taxon, are similar enough that the Eastern population
cannot be characterized as unusual or unique (i.e., they occupy
relatively high elevation, moist, subalpine, or boreal forest habitat).
Consequently, there is not substantial evidence in the petition or in
our files to support unusual or unique ecological settings as a
significant factor in differentiating the Eastern population from other
areas throughout the range of the boreal toad taxon.
Significant Gap in Range
The petition states the Eastern population (which includes the SRM
population) constitutes approximately 20 percent of the subspecies'
range in the conterminous United States and that this should be
considered a significant gap in the range should boreal toads in the
Eastern population become extirpated. Based on a review of the
information in the petition and available in our files, there appears
to be sufficient information to indicate that there may be a
significant gap in the range of the species if the Eastern population
were lost. We will further investigate this in our 12-month status
review.
Marked Differences in Genetic Characteristics
For the Eastern population, two studies suggest through mtDNA
analysis that the combination of the clades that make up the Eastern
population of the boreal toad could be considered a separate species or
subspecies. These hypotheses are based on different haplotypes between
the clades that make up the Eastern population (Eastern Major and Clade
3-1) and the clades to its north (Northwest Major and Clade 3-2)
(Goebel et al. 2009, pp. 215, 223; Switzer et al. 2009, pp. 18-26). A
phylogeographic study in Nevada also suggests that boreal toads in the
Bonneville Basin could be distinct from toads further to the west in
Nevada, thereby supporting the idea that the Eastern population is a
genetically distinct population (Noles 2010, pp. 24, 50, 51). Based on
information provided in the petition and in our files on differing
haplotypes between the Eastern population and clades to the north, we
find that the Eastern population of boreal toad may be significant.
DPS Determination for the SRM Population
For the reasons described above, we determine that there is not
substantial information in the petition and in our files to suggest
that the SRM population of boreal toads may be a valid listable entity
(DPS). Although this population appears geographically discrete, we did
[[Page 21929]]
not find substantial information to suggest that it may be significant
according to the standard in our DPS Policy. Therefore, we will not
evaluate the status of this population further in this finding.
DPS Determination for the Eastern Population
Based on current knowledge from genetic studies and distribution
information, there appears to be some genetic and geographic overlap of
the Eastern population with populations of boreal toads to the north of
the Eastern population. However, some genetic and geographic overlap is
allowed by the DPS Policy, and we have determined that the extent of
this overlap may be within the bounds of the DPS Policy. Therefore,
considering information in the petition and readily available in our
files, we find there is substantial information that the Eastern
population of boreal toads may be a valid DPS based on sufficient
genetic and geographic discreteness from the other boreal toad
populations, and based on evidence of significance, including the
significant gap in the range of the boreal toad that would be created
if the Eastern population should become extirpated. In addition, marked
(significant) genetic haplotype differences between the Eastern
population and other populations of boreal toads to the north also
support our determination that there is substantial information that
the Eastern population may be a valid listable entity (DPS). We will
further analyze the validity of this potential DPS with respect to our
DPS policy during the 12-month finding.
Evaluation of Information for This Finding
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations at 50 CFR part 424 set forth the procedures for adding a
species to, or removing a species from, the Federal Lists of Endangered
and Threatened Wildlife and Plants. A species may be 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 threatened or endangered as those terms are defined by the
Act. This does not necessarily require empirical proof of a threat. The
combination of exposure and some corroborating evidence of how the
species is likely impacted could suffice. The mere identification of
factors that could impact a species negatively may not be sufficient to
compel a finding that listing may be warranted. The information shall
contain evidence sufficient to suggest that these factors may be
operative threats that act on the species to the point that the species
may meet the definition of threatened or endangered under the Act.
In making this 90-day finding, we evaluated whether information
regarding threats to the Eastern population of the boreal toad, as
presented in the petition and other information available in our files,
is substantial, thereby indicating that the petitioned action may be
warranted. Our evaluation of this information is presented below.
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Information Provided in the Petition
The petition states that water management, roads, livestock
grazing, recreation, timber harvest, residential and commercial
development, pollutants, and energy and minerals management are all
activities that destroy, modify, or curtail the boreal toad's habitat
or range. The petitioners believe that any of these activities could
contribute to the decline of the boreal toad.
Water Management--The petition cites several studies to show that
water management can lead to direct habitat loss, habitat
fragmentation, and detrimental alteration of natural hydrological
regimes, through a number of activities, including draining or filling
of wetlands, water diversion for municipal or agricultural purposes,
dam and reservoir construction, dewatering of habitats, bank
stabilization, and stream channelization (Loeffler 2001, p. 12 ; McGee
and Keinath 2004, p. 37; Hogrefe et al. 2005, p. 19; Stoddard et al.
2005, p. 6). The petition also states that extended hydroperiods of
wetlands can increase densities of invertebrate predators and
establishment of predatory fishes (Scott 1996, pp. 45-46; Skelly 1996,
pp. 599-604).
Roads--The petition states that roads cause habitat fragmentation,
prevent migration, cause mortality, and alter water flow that sustains
aquatic habitats (Lehtinen et al. 1999, p. 2; Loeffler 2001, p. 12;
Hogrefe et al. 2005 p. 17). The petition also states that amphibians in
general are particularly vulnerable to road mortality. The petition
states that other detrimental factors may include pollutants, erosion
and sedimentation, vibrations, and noise. The petition cites several
additional studies to support these claims, but these references were
not provided to us or readily available in our files. One article and
one personal communication referenced in the petition state that
several boreal toad mortalities have been observed, but other
references either do not provide specific information or appear to be
general and would not provide information specific to the boreal toad.
Livestock Grazing--The petition states that livestock trample
boreal toads and their habitat. Trampling of habitat could cause
further mortality to boreal toads from loss of vegetative cover
resulting in desiccation (Bartelt 2000, pp. 98; Hogrefe et al. 2005, p.
15). The petition also provides information to suggest that livestock
grazing may cause declines in water quality from excess nutrients,
reduction in vegetation that helps filter water, and reduced survival
of eggs and tadpoles from increased siltation, water temperatures, and
fecal contamination (Loeffler 1998, p. 54; McGee and Keinath 2004, pp.
33-34; Hogrefe et al. 2005, p. 15). The petitioners argue that insect
abundance (toad prey) also may be reduced by livestock grazing
(Fleischner 1994, pp. 631-632). The petitioners state that prairie-dog
or other rodent control programs for livestock management reduce
availability of burrows for overwintering toads (Sharps and Uresk 1990,
pp. 339-345). The petition also suggests that compaction of soils may
potentially limit the availability of burrows that help prevent
desiccation and freezing of toads, that overutilization of tall
herbaceous cover may make adult toads more susceptible to predation,
and that grazing contributes to a decline in beaver populations that
may, in turn, result in less boreal toad habitat. The petitioners
[[Page 21930]]
did not provide references to support most of the above claims, and we
do not have data readily available in our files to support such claims.
Recreation--Recreation is cited in the petition as impacting
amphibians through loss of eggs, tadpoles, metamorphs, and adults due
to trampling, vehicle impacts, habitat degradation, an increase in
predators attracted to human refuse, and transfer of pathogens between
boreal toad populations (Hogrefe et al. 2005, p. 17). The petition
states that human handling and pet-related mortality of boreal toads
also may occur. The petition provides examples of where some of these
activities have impacted boreal toads, and cites references that were
not available to us in our files.
Timber Harvest--The petition states timber harvest may cause (1)
mortality through crushing by equipment, (2) interruption of dispersal
from breeding sites, or of late-summer dispersal of adults into
uplands, (3) soil compaction that limits the availability of burrows
used for overwintering hibernacula, (4) a reduction of available
refugia through burning of slash piles and downed woody materials, (5)
sedimentation that could disturb habitat, and (6) the spread of
nuisance species. The petition states that any timber harvest activity
that affects wetlands could have negative impacts to the boreal toad
(Loeffler 1998, pp. 56-57; Bartelt 2000, pp. 20-27, 74-77; McGee and
Keinath 2004, pp. 32-33). However, only one of the references available
to us on this topic was specific to the species, showing that effects
to boreal toads from interruption of dispersal by timber harvest have
been documented (Bartelt 2000, pp. 20-27, 74-77).
Residential and Commercial Development--The petition states that
residential and commercial development have potentially caused
extirpation of boreal toads in several areas in Utah and Colorado
(Thompson et al. 2004, p. 257).
Pollutants--The petition states that pollutants including
herbicides, insecticides, and piscicides are harmful to amphibians
(Loeffler 2001, p. 13; Hayes et al. 2002, pp. 5476-5479). The petition
also states that high salinity concentrations may affect toad
equilibrium and that a high proportion of streams in the range of the
Eastern population of boreal toad have high salinity (Dole et al. 1985,
pp. 645-648; Stoddard et al. 2005, p. 40).
Energy and Minerals Management--The petition states that energy and
minerals management causes habitat loss and fragmentation from new
roads, well pads, pumps and other facilities, and utility lines, and an
increase in human presence from vehicle traffic and construction
activity (U.S. Bureau of Land Management (BLM) 2005, pp. 3-29).
Evaluation of Information Provided in the Petition and Available in
Service Files
Water Management--Alteration of natural hydrology and hydrologic
processes, such as removal of water sources, shortening or lengthening
water availability, and flooding large areas of habitat or dispersal
corridors could cause impacts to the boreal toad (Loeffler 2001, p. 12;
Hogrefe et al. 2005, p. 19). It is possible that extended hydroperiods
of water bodies could increase densities of invertebrate predators and
allow establishment of predatory fishes. It also is possible that water
manipulation could decrease rates of boreal toad reproduction and
recruitment (Scott 1996, pp. 45-46; Skelly 1996, pp. 599-604; Semlitsch
2002, pp. 621-623; McGee and Keinath 2004, p. 37). The creation of
Lefthand Reservoir in Boulder County, Colorado, flooded a large
wetland, forcing boreal toads to its margins where habitat may not have
been as suitable (Campbell 1970a, p. 7; Hammerson 1999, p. 92).
Reservoirs may not have suitable shallow water for breeding, and open
water replaces foraging habitat around previously existing wetlands
(Hammerson 1999, p. 92). However, the information in the petition and
in our files did not provide any substantial information or analyses to
suggest that these effects are occurring in a widespread basis in the
Eastern population of boreal toads.
The petition states that a substantial proportion of streams
located within the range of the Eastern population of boreal toads have
been impacted by disturbance, and cites a study illustrating an average
30-40 percent disturbance of stream corridor riparian areas, about 10
percent disturbance of riparian vegetation, and 10-20 percent
disturbance of streambed stability by stressors in the Southern Rockies
and Northern Rockies ecoregions (Stoddard 2005, p. 40, fig. 15). The
stream corridor riparian area category does indicate a moderate amount
of disturbance to potential boreal toad habitat loss and fragmentation.
However, the number and extent of streams in this study that were
occupied by boreal toads is unknown, so the extent of impact is
indeterminable.
The petitioners state that wetland losses have occurred throughout
Utah and are expected to continue due to human population growth (Lee
2001, p. 4). There are numerous wetlands and water sources within the
range of the boreal toad that have not been impacted, but there has
been alteration of riparian and wetland habitat and hydroperiods due to
water development and use. We believe this issue is the most likely
activity under Factor A to cause impacts to the boreal toad. However,
the petition and the information in our files does not detail the
extent of wetland or riparian habitat alteration as it corresponds to
effects on boreal toad habitat. The petition does not provide an
analysis of water management impacts to boreal toads. Consequently, we
find that localized impacts from water management activities may occur,
but the petition and information in our files does not present
substantial scientific or commercial information indicating that water
management activities are a threat for the Eastern population of the
boreal toad.
Roads--Roads could cause direct mortality by vehicle strike as well
as direct loss of habitat, fragmentation, sedimentation, and alteration
of hydrology, and could potentially limit dispersal and gene flow
(Lehtinen et al. 1999, pp. 1-12; Loeffler 2001, p. 12; Hogrefe et al.
2005, p. 17). However, while the petitioners mapped major roads in the
range of the boreal toad, they provided limited specific evidence of
road impacts to boreal toad populations (Hogrefe 2005, p. 17; Greenwald
et al. 2011, pp. 26, 72). The references referred to by the petition as
supporting impacts from roads were general in nature and did not speak
directly to the boreal toad or its habitat. Although there are some
heavily traveled roads in or near boreal toad habitat, the majority of
roads are less-traveled dirt roads that we do not believe cause a high
level of mortality or other impacts to boreal toads. We find that
localized impacts from roads may occur but the petition and information
in our files does not present substantial scientific or commercial
information indicating that roads may threaten the Eastern population
of the boreal toad.
Livestock Grazing--Livestock grazing can occasionally cause direct
mortality to boreal toads (Bartelt and Peterson 1996, p. 14; Bartelt
2000, p. 98; Hogrefe et al. 2005, p. 15). Additionally, grazing can
cause boreal toad habitat destruction and degradation through eating
and trampling of vegetation and possible water quality reduction
through bank erosion and water contamination (Fleischner 1994, pp. 631-
632; Loeffler 1998, p. 54; Bartelt 2000, pp. 98, 20-27, 74-77; McGee
and Keinath 2004, pp. 33-34; Hogrefe et al.
[[Page 21931]]
2005, p. 15). Clear-cutting (removal of all trees in an area) has been
shown to adversely affect boreal toads by creating open spaces that are
too dry (and presumably too cold at night) for toads (Bartelt 2000, pp.
20-27, 74-77). If livestock are removing vegetation in large areas,
adverse conditions similar to those resulting from clear-cuts could
occur. However, the references in the petition and additional
references in our files (Bartelt and Peterson 1996, entire) only
mention occasional direct effects to the boreal toad and only the
possibility of widespread habitat threats. We find that localized
impacts from grazing may occur, but the petition and information in our
files do not present substantial scientific or commercial information
indicating that grazing may be a threat to the Eastern population of
boreal toad.
Recreation--Recreation from camping, hiking, biking, fishing, and
off-highway vehicle use could impact boreal toad habitat and bring
increased predation and the chance of pathogen introduction (Loeffler
1998, p. 51). Potential effects from these activities include transfer
of disease, including Bd, into uninfected habitats, along with
trampling, loss of vegetation, reduced water quality, and loss of
habitat (Hogrefe et al. 2005, pp. 15, 17). Human activities around
boreal toad breeding sites could increase the presence of ravens and
jays, which could increase predation on boreal toads. However, we are
not aware of studies that specifically researched effects of recreation
on boreal toads. We find that localized impacts from recreation may
occur, but the petition and information in our files do not present
substantial scientific or commercial information indicating that
recreation may be a threat to the Eastern population of boreal toad.
Timber Harvest--Timber harvest activities, especially clear-cuts,
can have detrimental effects to the boreal toad by interrupting
dispersal corridors, causing sedimentation of streams, causing impacts
to wetland and riparian vegetation used by toads, and affecting habitat
by prescribed burning of slash piles or downed woody material (Bartelt
and Peterson 1994, pp. 18-19; Loeffler 1998, pp. 56-57; Bartelt 2000,
pp. 20-27, 74-77; McGee and Keinath 2004, pp. 32-33). Timber harvest
equipment can cause direct mortality and compaction of soils that
reduce burrow availability for shelter or overwintering (Loeffler 1998,
pp. 56-57; McGee and Keinath 2004, pp. 32-33). Although local impacts
to habitat may occur from slash pile or downed woody material burning
in timber harvest areas, prescribed burning or wildfires can promote
longevity of wetland areas that boreal toads need by preventing build-
up of vegetation and subsequent succession to other habitat types
(Russell et al. 1999, pp. 374-384). We find that localized impacts from
timber harvest activities may occur, but the petition and information
in our files does not present substantial scientific or commercial
information indicating that timber harvest activities occur frequently
enough that they may be a threat to the Eastern population of boreal
toad.
Residential and Commercial Development--Some boreal toad habitat
loss could be attributed to development on the Wasatch Front between
Salt Lake City and Provo, Utah; rapid population growth in this area
has likely contributed to boreal toad habitat impacts and possible
extirpations (Lee 2001, p. 4; Thompson 2004, p. 257). Ski areas and
associated residential development in Colorado also were identified in
the petition as causing habitat loss or degradation. The petition did
not cite any references on the effects of ski areas, but an article on
home ranges of boreal toads documents the potential impacts of ski area
development by mentioning ski area proximity and related county
setbacks in Summit County, Colorado (Muths 2003, p. 163). Ski area
development and associated housing have likely impacted localized
areas, but boreal toads currently face little threat from residential
and commercial development due to the higher elevation habitat they
occupy. We find that localized impacts from residential and commercial
development may occur, but the petition and information in our files do
not present substantial scientific or commercial information indicating
that residential or commercial development may be a threat to the
Eastern population of boreal toad.
Pollutants--There are observations and studies describing potential
impacts to the boreal toad from mine runoff and acidification (Porter
and Hakanson 1976, pp. 327-331; Corn et al. 1989, entire; Corn and
Vertucci 1992, entire; Loeffler 1999, pp. 31-32; Jackson 2006, pp. 58-
59). However, impacts are likely localized. Although it was
hypothesized that a short-term acidic pulse from snowmelt could produce
effects to amphibians, acidification was not found to be a factor in
regional amphibian declines in the Rocky Mountains (Corn and Vertucci
1992, p. 367). Another study demonstrated that pH would have to be
below 4.9 to produce negative effects to boreal toad embryo survival,
but pH in the elevations common for boreal toad occurrence is typically
between 7 and 6 (Corn et al. 1989, pp. 19, 20, 28). Therefore,
information in the petition and in our files suggests that localized
impacts from pollutants may occur, but there is not substantial
information to demonstrate that the impacts are pervasive enough that
they may be a threat to the Eastern population of the boreal toad.
Studies have illustrated the effects of pesticides and herbicides
on amphibians, and deposition by drift can occur (Berrill et al. 1994,
p. 663; Hayes et al. 2002, pp. 5476-5479; Fellers et al. 2004, p. 2176;
Relyea 2005, p. 626). However, to our knowledge there is limited
application of pesticides or herbicides in or near boreal toad habitat.
Forest management activities such as fire retardant drops are
infrequent, and piscicide application also is infrequent. In addition,
we do not agree with the petitioners that a high proportion of streams
in the range of the Eastern population of the boreal toad have high
salinity levels (Stoddard 2005, p. 40, fig. 15). In fact, we believe
they misinterpreted information in their reference source, because
ecoregion locations (described in the reference) where boreal toads
primarily occur (Southern Rockies, Northern Rockies, and Northern Xeric
Basins) have very low salinity (Stoddard 2005, p. 40, fig. 15).
Salinity from road salts could impact localized breeding sites, but we
expect the occurrence of these impacts is rare across the range and
would likely occur along heavily traveled roads only. Overall, we find
that localized impacts from pollutants may occur, but the petition and
information in our files do not present substantial scientific or
commercial information indicating that pollutants may be a threat to
the Eastern population of boreal toad.
Energy and Minerals Management--Energy and mineral development can
cause habitat loss and fragmentation from roads, utility lines, and
other facilities, and can increase human presence in mining areas. As
the petition points out, hardrock mines in Colorado may impact boreal
toads, but boreal toads continued to inhabit the Urad/Henderson Mine in
large numbers until Bd arrived there in 1999 (Loeffler 1999, pp. 31-32;
Jackson 2006, pp. 27, 58-59). In fact, there is speculation that Bd-
infected boreal toads at the Urad/Henderson Mine may have had better
survival from the infection due to inhabiting water with mine effluent
than boreal toads not inhabiting waters in the effluent area (Jackson
2006, pp. 58-59). Mining may increase human presence in boreal toad
habitat and some mortality may occur from vehicles or people, but with
the general decline in hardrock mining activity over the last several
decades, we believe the risk of
[[Page 21932]]
mortality from mining-related activities is low.
We also are not aware that oil and gas development is a widespread
activity in boreal toad habitat. In Colorado, where extensive oil and
gas development has occurred, an extremely small amount of oil and gas
development occurs in boreal toad habitat and the majority of boreal
toad habitat is located in areas that have low to no potential for oil
and gas development (Gunnison Sage-grouse Rangewide Steering Committee
2005, p. 130; Colorado Greater Sage-grouse Steering Committee 2008, p.
112). We find that localized impacts from energy and minerals
management may occur, but the petition and information in our files do
not present substantial scientific or commercial information indicating
that energy and minerals management may be a threat to the Eastern
population of the boreal toad.
Summary for Factor A
Based on the information provided in the petition, as well as other
information readily available in our files, we find that the petition
does not present substantial scientific or commercial information
indicating that the Eastern population of the boreal toad may warrant
listing due to the present or threatened destruction, modification, or
curtailment of the species' habitat or range. Although each of the
issues evaluated under Factor A may impact the Eastern population of
the boreal toad locally, the information in the petition and in our
files does not indicate that these rise to the level of a threat to the
population. There is no information presented in the petition or
contained in our files that the threats described under Factor A
cumulatively threaten the Eastern population of the boreal toad.
However, we will evaluate this factor and cumulative effects of the
threats described under this factor more thoroughly during the 12-month
status review if we determine that a valid DPS of boreal toad exists.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petition states there is little information on the extent of
boreal toad collection or harvesting (McGee and Keinath 2004, p. 37).
Some boreal toads, eggs, or tadpoles have been collected by
universities, State wildlife agencies, zoos, and other institutions for
propagation, translocation, genetic research or other scientific study,
or educational purposes. However, information in our files shows that
entities involved in these activities in the SRM population area have
developed protocols to avoid or minimize mortality or injury to boreal
toads (Scherff-Norris 1997, entire; Loeffler 2001, pp. 36-53).
Additionally, the Utah Conservation Plan provides general procedures to
minimize impact of collection activities and outlines plans for
development of protocols (Hogrefe et al. 2005, pp. 28-38). Due to
collection and handling procedures implemented by these entities, and
the lack of known collection pressure from the public, we do not
consider overutilization of the boreal toad to be occurring. Based on
our evaluation, neither the petition nor information in our files
presents substantial scientific or commercial information to indicate
that overutilization for commercial, recreational, scientific, or
educational purposes may present a threat to the Eastern population of
the boreal toad such that the petitioned action may be warranted.
However, we will evaluate this factor more thoroughly during the 12-
month status review if we determine that a valid DPS of boreal toad
exists.
C. Disease or Predation
Information Provided in the Petition
Disease--The petition states that the chytrid fungus (Bd) is the
primary pathogen of concern for the Eastern population of the boreal
toad (Fellers et al. 2001, pp. 945, 952; McGee and Keinath 2004, pp.
23-24; Hogrefe et al. 2005, p. 13). The petition states that Bd attacks
the skin of boreal toads and can cause chytridiomycosis (the disease
that can result from Bd infection), resulting in 90-100 percent
mortality (McGee and Keinath 2004, pp. 43-44). The exact mechanism of
mortality caused by Bd infection is not understood, but possible
mechanisms include disruption of water, oxygen, and ion exchange and
secretion of toxins from the Bd associated with chytridiomycosis
(Berger et al. 1998, p. 9036).
The petition also claims that red-leg disease (Aeromonas
hydrophila), a fungus called Saprolegnia ferax, and a trematode
(Ribeiroia ondatrae) have all been documented to cause mortality or
malformations in amphibians and also could impact the Eastern
population of boreal toads (Johnson et al. 2001, pp. 370-379; Kiesecker
et al. 2001, entire; Hogrefe et al. 2005, p. 14). The petition states
that nonnative species, such as bullfrogs (Rana catesbeiana) and
certain species of fish, may impact the boreal toad by transmitting
pathogens, including Bd and Saprolegnia ferax (Kiesecker et al. 2001,
p. 1069; Schloegel et al. 2010, p. 53).
Predation--The petition states that, despite boreal toad adults'
having toxic skin secretions, boreal toads have many native predators
that are suspected of depressing toad populations (Arnold and Wassersug
1978, entire; Flier et al. 1980, entire; Beiswenger 1981, entire;
Brodie and Formanowicz 1987, entire; Olson 1989, entire). The petition
states that nonnative predators, such as trout or bullfrogs, also may
reduce populations of boreal toads (Bahls 1992, pp. 183, 191; McGee and
Keinath 2004, pp. 38-39).
Evaluation of Information Provided in the Petition and Available in
Service Files
Disease--Bd was first identified in the late 1990s from a captive
blue poison dart frog (Dendrobatis azureus) (Longcore et al. 1999,
entire). Since then, Bd has been reported in numerous species of
amphibians worldwide and is most likely a recent introduction to North
America (Berger et al. 1999, p. 29; Lips et al. 2003, entire). However,
Bd has been present since at least the early 1970s in America. A
specimen from Colorado preserved in 1974 was tested for Bd and was
found to have the fungus present (Hogrefe et al. 2005, p. 14). As
stated above, Bd attacks the skin of boreal toads and may cause
chytridiomycosis, which can result in serious disruption of cutaneous
respiration and osmoregulation (Berger et al. 1998, p. 9036).
Boreal toads on the Paunsaugunt Plateau in southern Utah were
reported to be infected with Bd in 2005, and chytridiomycosis is the
suspected cause of boreal toad mortalities in this population (Hogrefe
et al. 2005, pp. 14, 26). The Paunsaugunt Plateau (represented by up to
seven sites comprising one or two breeding populations) was the only
area out of six areas in the UDWR's Southern Region that was positive
for Bd infection as of 2009 (UDWR 2010, p. III-3). The Paunsaugunt
Plateau had only one adult toad observed in 2009 at one out of seven
sites monitored on the Plateau, although a couple of other sites on the
Paunsaugunt Plateau had tadpoles observed (UDWR 2010, pp. III-3, 5).
The low number of toads suggests that Bd has affected toads on the
Paunsaugunt Plateau.
In 2008, 77 Bd swabs (DNA samples taken for analysis of Bd presence
or absence) were taken from boreal toads at Strawberry Reservoir in the
Central Region of the Utah Division of Wildlife Resources, with 38 of
those samples (49 percent) testing positive for Bd (UDWR 2010, p. II-
4). In 2009, 105 toads were detected at 3 sites at Strawberry
Reservoir; however, the impacts of Bd on boreal toad recent population
trends
[[Page 21933]]
are uncertain (UDWR 2010, pp. II-3, II-10). In the Northeast Region of
the UDWR, only 1 of 27 Bd swabs taken in 2008 tested positive for Bd
(UDWR 2010, p. IV-4). Although some swabs are positive for Bd
infection, Bd test results among regions in Utah are variable, and it
is unknown whether or not Bd is causing declines in boreal toad
populations there. However, it is clear that the infection is present
across Utah.
Surveyors and researchers in the SRM population collected 417
samples from 46 sites across Colorado in 2003, and subsequent analysis
detected 33 toads at 8 sites with Bd (Jungwirth, 2004, p. 53). It also
was discovered from the study that, at sites with Bd, adult and
juvenile toads had a 77 percent prevalence rate of infection (Jungwirth
2004, p. 54). Metamorphs often do not test positive at known Bd
positive sites, and it is theorized that metamorphs may not have enough
exposure time to the terrestrial environment to become infected with Bd
(Jungwirth 2004, p. 54). Furthermore, at toad breeding sites tested
through the 2007 field season, 22 breeding sites tested positive for
Bd, 35 tested negative, and 22 additional sites were not tested
(Jackson 2008, p. 6).
Even though Rocky Mountain National Park (RMNP) is one of the most
protected environments within Colorado, boreal toad populations have
declined in the park (Corn et al. 1997, pp. 40, 42). Four sites were
monitored in RMNP from 1990 to 2001, and significant declines of boreal
toads were noted at two of the sites (Kettle Tarn and Lost Lake),
although all sites declined (Muths et al. 2003, p. 5). Six adult toads
that were suitable for histologic analysis all had Bd detected on them,
and another four of six that had preliminary molecular analysis
conducted on them were also determined to have Bd infections (Muths et
al. 2003, p. 8). Based on analysis for other diseases, it was
determined that Bd was the certain cause of decline (Muths et al. 2003,
pp. 8-9). Evidence of the decline is supported by monitoring data
showing that Lost Lake had 100-300 toads present from 1991 to 1998, but
fell to 30 or fewer since then (Jackson 2008, p. 57). Kettle Tarn had a
hundred or more toads from 1991 through 1995 but exhibited a similar
precipitous decline afterwards (Jackson, 2008, p. 58).
Bd testing has not been conducted in the remaining population in
southeastern Wyoming (Jackson 2008, p. 91). However, as with the rest
of the SRM population, Bd is the suspected cause of declines in
southeastern Wyoming (Jackson 2008, p. 4). As stated above, boreal
toads were extirpated in New Mexico for many years, but reintroduced
there in 2008 and 2009. However, in 2009 seven boreal toads from the
2008 release were recaptured, but six of the seven tested positive for
Bd (NMDGF 2010, p. 3). This indicates that chytridiomycosis probably
extirpated them in the past, and chance of survival of reintroduced
toads is low. We currently have no information on Bd occurrence in
southeastern Idaho, northeastern Nevada, or southwestern
Wyoming.Overall, Bd appears to be widespread, and is known to occur in
the SRM and Utah.
Given its widespread distribution in the SRM area, Utah, and around
the world, it is likely present in the rest of the Eastern population
and is almost assuredly the primary reason for declines observed in
boreal toads in the Eastern population.
The fungal disease Saprolegnia ferax was spread to boreal toads
from rainbow trout (Oncorhynchus mykiss) experimentally infected with
S. ferax (Kiesecker et al. 2001, p. 1064). Although transmission of the
disease from fish to boreal toads can occur, we have no information
indicating that S. ferax is prevalent in the wild or has caused boreal
toad declines in the wild.
We also have no information in our files to suggest that the
trematode Ribeiroia ondatrae poses a threat to the boreal toad. The
petitioners provided one article cited in the petition that found high
frequencies (40-85 percent) of severe limb malformations in surviving
western toads (Anaxyrus boreas) and decreased survivorship (42 percent)
in toads with the heaviest treatment of trematodes in an induced
laboratory experiment (Johnson et al. p. 370). However, effects of the
trematode to wild boreal toads is not known, and the petition admits
that further study is needed before any conclusions can be drawn on
effects of the trematode to the boreal toad. Consequently, the petition
did not present substantial information to suggest that the trematode
may be a threat.
In conclusion, studies and information presented above illustrate
that Bd may be the major factor in the decline of the boreal toad and
that it poses a significant threat to the Eastern population of the
boreal toad (Loeffler 2001, p. 13; Hogrefe et al. 2005, pp. 13-14). We
find that the petition and information in our files present substantial
scientific or commercial information indicating that disease,
specifically Bd resulting in chytridiomycosis, may be a threat to the
Eastern population of the boreal toad.
Predation--The petition and information in our files show that
adult boreal toads have several avian, mammalian, and reptilian
predators (Olson 1989, entire; Hammerson 1999, p. 97; Livo 1999, p. 1).
Avian, reptilian, insect, and even other amphibian predators of
tadpoles and newly metamorphosed boreal toads also have been recorded
(Beiswenger 1981, entire; Hammerson 1999, p. 98). Both garter snakes
(Thamnophis elegans) and spotted sandpipers (Actitis macularia) are
often encountered at boreal toad breeding sites in Colorado (Lambert
2003, pp. 22, 24, 77). At Brown's Creek in Colorado, garter snakes are
suspected to be responsible for poor survivorship of boreal toad
tadpoles (Lambert 2003, pp. 24, 77). It is likely that poor
survivorship from predation occasionally results, but other than
Lambert (2003, p. 22, 24, 77), we have no evidence that this occurs
often enough or to an extent that it suppresses survival at breeding
sites or breeding populations to a point that it may threaten the
Eastern population of the boreal toad.
Nonnative predators, such as bullfrogs or stocked trout, were
asserted by the petitioners to cause impacts to the boreal toad. We do
not have any information that suggests that bullfrogs prey on boreal
toads, since bullfrogs have never been documented in boreal toad
habitat. Trout have been stocked in many lakes in the western United
States, many of which were fishless prior to stocking (Bahls 1992, p.
183). The presence of stocked trout has been found to exclude frogs
from lakes in the Sierra Nevada Mountains (Bradford 1989, pp. 776-777).
However, laboratory experiments have indicated that American toad (Bufo
americanus) tadpoles may be less palatable than chorus frog tadpoles
(Pseudacris triseriata) to certain species of fish (Voris and Bacon
1966, p. 597) and we suspect that boreal toad tadpoles have similar
toxins as the American toad. Additional evidence is that cutthroat
trout (Salmo clarkii) mouthed then rejected boreal toad eggs that were
fed to them (Licht 1969, p. 296). Although trout may injure boreal toad
eggs or tadpoles by mouthing them, it appears that predation on boreal
toads may be limited, due to the trout's avoidance of toxins in the
eggs and tadpoles.
Localized predation from native or nonnative predators may
sporadically occur and could occasionally cause declines or extirpation
of breeding sites or breeding populations. However, we find that the
petition and information in our files does not present substantial
scientific or commercial information indicating that predation may rise
to the
[[Page 21934]]
level of a threat to the Eastern population of the boreal toad.
Summary for Factor C
Based on our evaluation, the petition and information in our files
present substantial information that listing the Eastern population of
the boreal toad due to disease may be warranted. Localized predation
may cause effects to breeding sites or breeding populations, but the
petition and information in our files do not present substantial
information that listing the Eastern population due to predation may be
warranted. However, we will evaluate this factor more thoroughly during
the 12-month status review if we determine that a valid DPS of boreal
toad exists.
D. The Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
The petition states that the boreal toad has been State-listed as
endangered in Colorado and New Mexico (NMDGF 1988, p. 1; CDOW 1993, p.
2). The petition also states that the toads are designated as a State
Sensitive Species in Utah. In Wyoming, the boreal toad is designated as
a Native Species Status 1, which means the species and habitat are
declining (McGee and Keinath 2004, p. 46). The petition states that the
designations in Utah and Wyoming garner no legal or regulatory weight.
The petition also states that boreal toads are designated as nongame
species in Idaho, protecting them from collection. There is no
designation for the boreal toad in Nevada.
The petition states that a Colorado recovery plan was completed in
1994, and a recovery plan for New Mexico was completed in 2006 (Nesler
and Goettle 1994, entire; Pierce 2006, entire). The petition states
that in Utah a conservation plan for the toad also has been completed
(Hogrefe et al. 2005, entire). The petition adds that Idaho and Nevada
do not have conservation plans for the boreal toad.
The petition states that the majority of boreal toad habitat in the
Southern Rocky Mountains is on U.S. Forest Service (USFS) land. The
petition also points out that the USFS in both Region 2 (Colorado and
southeast Wyoming) and Region 3 (New Mexico) classifies the toad as a
sensitive species. However, USFS Region 4 (western Wyoming, southern
Idaho, Nevada, and Utah) does not classify the toad as a sensitive
species. The petition mentions that only two forests, the White River
National Forest and Medicine Bow National Forest (in Colorado and
Colorado/Wyoming, respectively), have forest plans that contain
standards and guidelines for managing the boreal toad. However, the
petition notes that the two forests only cover a small portion of the
range of the toad and the forest plans do not adequately address all
the threats to the toad. The petition also states that the Uintah
National Forest, which covers a small area of the range of the Eastern
population of the boreal toad, has a voluntary guideline to protect
boreal toad habitat from disturbance (trampling) during the breeding
season.
The BLM classifies the boreal toad as a sensitive species in
Wyoming, Colorado, Utah, and Idaho. The petition points out that a
State-led Boreal Toad Recovery Team comprised of State and Federal
agencies, and an associated Technical Advisory Group comprised of
university, State, Federal, and local government staff was formed and
produced a conservation plan for the boreal toad in the Southern Rocky
Mountains in 1998 (Loeffler 1998, entire) and revised the plan in 2001
(Loeffler 2001, entire).
The petition states that none of the State, USFS, or BLM
classifications or recovery or conservation plans are adequate to
protect the boreal toad, because they do not protect habitat, they
carry no legal or regulatory weight, and they have not been shown to
have improved the status of the toad. For example, the petition states
that the Utah Conservation Plan does not address all threats to the
boreal toad, such as Bd, and Bd has been detected in toads in Utah. The
petitioners also considered conservation agreements, and found the
specified actions to be implemented by involved parties within the SRM
conservation plan were vague and provided little protection to the
boreal toad. The petition states that even if all actions in the SRM
conservation plan were accomplished, it still would not adequately
address the impacts of Bd on boreal toads.
Evaluation of Information Provided in the Petition and Available in
Service Files
State listings in Colorado and New Mexico mean that possession of
the boreal toads is prohibited. In Idaho, the nongame regulations
prohibit possession of more than four boreal toads (Idaho
Administration Procedures Act 2010, p. 4). The boreal toad was
designated as a State Sensitive Species in Utah in 1997 (Hogrefe et al.
2005, p. 2). However, neither the Utah nor Wyoming sensitive species
designations protect the toad from possession. Obviously, the lack of
status in Nevada does not prevent possession of the toad there.
However, we have no information on whether collection and possession of
the boreal toad in any of the States is impacting the toad.
The Colorado Department of Parks and Wildlife (formerly Division of
Wildlife), Wyoming Game and Fish, NMDGF, and UDWR have led or been
instrumental in development of the State and SRM conservation plans,
along with the USFS, U.S. Geological Survey, National Park Service, and
BLM. Since the boreal toad was State listed in Colorado, considerable
effort and funding have gone towards research, management, captive
breeding, and translocation or repatriation of boreal toads in
Colorado, Wyoming, and New Mexico (the SRM population). University
staff, the U.S. Geological Service, zoos, and others also have been
instrumental in research into declines of the boreal toad and
propagation of the toad.
Despite development of the conservation plans (which are voluntary
and not regulatory in nature), and the designations by different State
and Federal agencies, the research and management actions that have
occurred, and the standards and guidelines put into place by the USFS,
there has been little success in conserving the boreal toad because of
the difficulty of arresting Bd-caused declines. However, the
overwhelming factor in the boreal toad's decline is chytridiomycosis
caused by Bd, which will likely affect the toads regardless of what
regulatory protections are in place.
Summary for Factor D
Even though the Federal agencies have not addressed or implemented
boreal toad management through all of their forest plans or resource
management plans, they do have guidance through their sensitive species
designations to manage for the toad. There have been management actions
for the toad carried out on Federal lands, but the Service does not
currently have information on the extent of implementation and
effectiveness of these actions. The States within the Eastern
population lack regulatory authority to protect the toad's habitat.
However, as stated above in Factor A, we did not find substantial
information to show that habitat destruction, modification, or
curtailment currently threaten the toad. Consequently, there is not
substantial information to indicate that regulations protecting habitat
are inadequate. Similarly, issues under Factors B, C, and E do not
currently appear to need further regulatory mechanisms or would not be
resolved by further regulatory mechanisms. Some of the States have
regulations that
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prohibit or limit possession of boreal toads; however, there is no
information to suggest that collection and possession of the boreal
toad in any of the States is impacting the toad. Consequently, there is
not substantial information to indicate that State regulations
prohibiting collection and possession, or lack thereof, are inadequate.
Nonetheless, as both we and the petitioners recognize, Bd may be
the overriding threat to the boreal toad, and we believe regulatory
mechanisms are not capable or have limited capability to reduce the
existing threat from Bd. Based on our evaluation, neither the petition
nor information in our files presents substantial information that
listing the Eastern population of boreal toad due to inadequacy of
existing regulatory mechanisms may be warranted. However, we will
evaluate this factor more thoroughly during the 12-month status review
if we determine that a valid DPS of boreal toad exists.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Information Provided in the Petition
Isolation--The petition states that many populations of boreal toad
are small and isolated (Hogrefe et al. 2005, p. 15). Isolation and
small population size can preclude genetic interchange and
recolonization of habitat in the face of impacts such as Bd or long-
term land management changes (Carey et al. 2005, pp. 235, 236). Lack of
gene flow also may cause loss of genetic variability (Wright 1931, pp.
98-102), causing inbreeding depression. The petition states that random
events, environmental factors, or human impacts may cause extirpation
of small, isolated populations.
Climate Change--The petition states that since boreal toads are
ectotherms (require heat from the sun or outside sources to warm
selves), their body temperature varies with their surroundings. The
petition states (?) boreal toad reproductive behavior and boreal toad
abundance may be affected by temperature changes resulting from climate
change (Blaustein and Wake 1995, pp. 2-4; Blaustein et al. 2001, p.
1808). The petition also states that warmer temperatures may allow for
the spread of disease, especially in higher elevations where currently
disease may not be as prevalent. The petition states drought and early
or late season freezing temperatures caused by climate change may dry
up breeding pools and cause mortality before or after hibernation
(McGee and Keinath 2004, p. 41). The petition states that warming will
limit activity of toads in different habitats (Bartelt et al. 2010, p.
2675). The petition also states that effects of climate change may have
already been observed through increasingly earlier breeding due to
warmer temperatures or reduced precipitation (Blaustein et al. 2001, p.
1806; Corn 2003, p. 624).
Ultraviolet Radiation--The petition states that degradation of the
ozone may be causing increases in ultraviolet-B (UV-B) radiation
(Stolarski et al. 1992, p. 342; Blumthaler et al. 1997, p. 130). The
petition states the boreal toad may be susceptible to UV-B radiation
due to not having protective hair or feathers, and not having
protective shells on their eggs, which are laid in shallow water
(Blaustein et al. 1994, p. 1791; Corn 1998, p. 19). Additionally, the
petition states that photolyase, an enzyme that repairs UV-B damage, is
lower in boreal toads than in some frogs and may cause lower hatching
success in boreal toads (Blaustein et al. 1994, p. 1794). However, the
petition also acknowledges that some studies show UV-B radiation is not
a factor in hatching success of red-legged frogs (Rana aurora) or
boreal toads (Blaustein et al. 1996, p. 1401; Corn 1998, pp. 22-23;
Loeffler 2001, p. 12).
Invasive Species--The petition discusses invasive species under
Factor E, but since the discussion focuses on disease transmission and
predation by invasive species, we address this under Factor C, Disease
or Predation, above.
Evaluation of Information Provided in the Petition and Available in
Service Files
Isolation--Isolation or small population size could cause
extirpation of boreal toad breeding colonies through habitat loss or
fragmentation or other human or environmental factors (such as Bd
infection), random events, or genetic problems. Microsatellite nDNA
analysis suggests that populations of boreal toads within the Eastern
population are isolated from one another, with little gene flow, and
that this could potentially cause genetic problems (Switzer et al.
2009, pp. 23, 25). Additional information suggests that boreal toad
populations in Utah are separated from each other due to long-term
climate change (over the last 10,000 years) and human development at
lower elevations resulting in genetic problems or loss of smaller
populations through random events (Hogrefe et al. 2005, pp. 14-15).
Diseases, such as chytridiomycosis, which is caused by Bd, also
could cause extirpation of these small populations. The SRM
conservation plan gives a general idea of a large ``population'' in the
viability criteria as 20 or more adult toads in a breeding ``locality''
(in this context ``locality'' is the same as a breeding population).
Monitoring in Colorado and southeastern Wyoming in 2009 revealed that
only 5 out of 47 breeding populations (11 percent), or 8 breeding sites
out of 73 (about 9 percent), had more than 20 adults (CDOW 2010,
entire). These statistics illustrate that very few populations in the
SRM portion of the Eastern population are large. Consequently, we
determine that the petition and information in our files present
substantial scientific or commercial information indicating that
isolation and small population size may be a threat to the Eastern
population of the boreal toad.
Climate Change--Ray et al. (2008, p. 1) predict that Colorado will
warm by about 1 [deg]C (2.5 [deg]F) by 2025 and by about 2 [deg]C (4.0
[deg]F) by 2050. Most of the observed snowpack loss in Colorado has
occurred below 2,500 m (8,200 ft), with snowpack loss above this
elevation predicted at between 10 and 20 percent (Ray et al. 2008, p.
2). With the range of the boreal toad largely above 2,500 m (8,200 ft)
in the southern Rocky Mountains, it is likely that they will be
shielded from extensive droughts. However, some drought effects were
noted in boreal toads in the southern Rocky Mountains in 2002 during a
drought cycle (Livo and Loeffler 2003, p. 11). Several breeding sites
either remained dry throughout the breeding season or dried up prior to
metamorphosis, reducing toad abundance. However, based on subsequent
years with more precipitation, the 2002 drought may have been within
normal variation and not related to climate change. Drought could
exacerbate the decline of localized boreal toad populations, but is not
considered a major factor in the widespread decline of the species.
There is a possibility that some diseases, such as
chytridiomycosis, could expand their range into higher elevation boreal
toad habitats if warmer temperatures occur due to climate change.
However, references on this subject listed in the petition are not
currently available to us and we have no information in our files to
support this hypothesis. Warming temperatures could affect evaporative
water loss from boreal toads, which could affect toad movement,
breeding, and genetic interchange (Bartelt et al. 2010, p. 2675).
Conversely, warmer temperatures could potentially help boreal toads by
lengthening the growing season and increasing the rate of growth,
leading to earlier metamorphosis and greater survival (Carey et al.
2005, p. 236). We
[[Page 21936]]
find that the petition and information in our files does not present
substantial scientific or commercial information indicating that
climate change may be a threat to the Eastern population of the boreal
toad.
Ultraviolet Radiation--The effect of increased UV-B radiation
resulting from ozone depletion has been implicated as a contributing
factor in amphibian declines, particularly on species inhabiting
mountainous regions. However, studies are conflicting as to whether UV-
B radiation has any effect on boreal toads and other frog species. A
correlation was demonstrated between increased levels of UV-B and
amphibian mortality in boreal toads and the Cascades frog (Rana
cascadae), but there was no effect of ambient UV-B radiation on red-
legged frog (R. aurora) hatching success (Blaustein et al. 1994, pp.
1791, 1793-1794). No evidence linking UV-B levels to the decline of the
boreal toad was found in another study (Corn 1998, pp. 18, 21-25).
Another study suggested that UV-B and pH could have synergistic effects
on embryonic success (Long et al. 1995, entire). However, as stated in
the ``Pollutants'' section under Factor A, pH does not appear to be an
issue for boreal toads, and, consequently, the synergistic effects of
UV-B and pH on boreal toads are not expected to occur in the wild.
Therefore, we determine that the petition and information in our files
do not present substantial scientific or commercial information
indicating that UV-B radiation may be a threat to the Eastern
population of the boreal toad.
Summary for Factor E
Based on our evaluation, the petition and information in our files
present substantial information that listing the Eastern population of
the boreal toad due to isolation and small population size may be
warranted. Based on our evaluation, neither the petition nor
information in our files presents substantial information that listing
the Eastern population of the boreal toad due to climate change or UV-B
radiation may be warranted. However, we will evaluate the potential
threat of climate change and UV-B radiation more thoroughly during the
12-month status review if we determine that a valid DPS of boreal toad
exists.
Finding
On the basis of our determination under section 4(b)(3)(A) of the
Act, we determine that the petition presents substantial scientific or
commercial information indicating that listing the Eastern population
of the boreal toad as a DPS may be warranted. This finding is based on
information provided under Factors C and E.
Because we have found that the petition presents substantial
information indicating that listing the Eastern population of the
boreal toad as a DPS may be warranted, we are initiating a status
review to determine whether listing the Eastern population of the
boreal toad under the Act is warranted. During the status review, we
will fully address the cumulative effects of threats discussed under
each factor. Additionally, if during the status review period the
Eastern population of the boreal toad is classified as its own species,
the Service will determine if listing the newly classified species is
warranted.
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 determine 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 and
12-month findings are different, as described above, a substantial 90-
day finding does not mean that the 12-month finding will result in a
warranted finding.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Western Colorado
Field Office (see FOR FURTHER INFORMATION CONTACT).
Author
The primary authors of this notice are the staff members of the
Colorado Field Office in Grand Junction and Lakewood, Colorado.
Authority: The authority for this action is the Endangered
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: March 27, 2012.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-8806 Filed 4-11-12; 8:45 am]
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