[Federal Register: August 30, 2002 (Volume 67, Number 169)]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 12-Month Finding
for a Petition To List the Wasatch Front Columbia Spotted Frog as
Threatened Throughout Its Range
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of petition finding.
SUMMARY: The U.S. Fish and Wildlife Service (Service) announces a 12-
month finding on a petition to amend the List of Endangered and
Threatened Wildlife. After review of all available scientific and
commercial information, the Service has determined that, pursuant to
the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.)
(Act), listing the Wasatch Front population of the Columbia spotted
frog (Rana luteiventris) is not warranted.
DATES: The finding announced in this notice was approved on August 23,
2002. Comments and information may be submitted until further notice.
ADDRESSES: Questions, comments, and additional information regarding
this finding should be sent to Mr. Henry Maddux, Field Supervisor, U.S.
Fish and Wildlife Service, 2369 West Orton Circle, West Valley City, UT
84119. Comments and materials received will be available on request for
public inspection, by appointment, during normal business hours at the
FOR FURTHER INFORMATION CONTACT: Jessica Gourley, e-mail <jess--
firstname.lastname@example.org, or Laura Romin, email <laura--
email@example.com, (see ADDRESSES section), telephone (801) 975-
On May 1, 1989, the Service received a petition from the Board of
Directors of the Utah Nature Study Society requesting the Service to
add the spotted frog (then referred to as Rana pretiosa) to the List of
Threatened and Endangered Species and to specifically consider the
status of the Wasatch Front, Utah, population. The petitioners stated
that ``the spotted frog's present range in the lower 48 states is
greatly reduced from its historic range,'' and that ``the current
status [of the species] is greatly reduced from historic times.'' The
petitioners further indicated that the ``scientific importance of the
spotted frog is that this species lives in many disjunct populations
that reflect Pleistocene populations.'' Threats identified by the
petitioners included loss of habitat (caused by dam and reservoir
construction, alteration of drainage patterns, urban and agricultural
use of water, and highway and bridge construction); introductions of
exotic species; lack of inventories of native wetland animals;
insufficient impact analyses conducted prior to development; and
inadequate mitigation activities. In addition, the petitioners alluded
that Federal and State laws and regulations do not adequately protect
wetlands and riparian areas for the spotted frog.
The Service published a notice of a 90-day finding in the Federal
Register (54 FR 42529) on October 17, 1989, concluding there was
substantial information that the petitioned action may be warranted.
Concurrent with publishing the notice, the Service initiated a status
review. The period of the status review was prolonged because,
throughout its wide range, there was a lack of quantitative information
documenting the spotted frog's current distribution and status.
Genetics research raised further questions regarding the
appropriateness of the then-current taxonomic classification of spotted
A notice of the 12-month petition finding was published in the
Federal Register (58 FR 27260) on May 7, 1993. In the 12-month petition
finding, the Service determined that listing the spotted frog as
threatened in some portions of its range was warranted but precluded by
other higher priority listing actions. Based on geographic and climatic
separation and supported by genetic separation (Green 1991), the
Service found five Distinct Population Segments (DPS) of spotted frogs
throughout its range--(1) the main population (Alaska, British
Columbia, Alberta, Wyoming, Montana, north and central Idaho, eastern
Washington, and northeastern Oregon), (2) the Great Basin (southern
Idaho and Nevada), (3) West Coast (western Washington, Oregon, Idaho,
and Nevada), (4) the Wasatch Front, Utah, and (5) the West Desert,
Utah. Separation of the West Desert and Wasatch Front DPSs in Utah is
supported by geographic isolation in addition to ecological and
demographic distinctiveness (Bos and Sites 2001).
Four of the five DPSs (all but the main population) were found to
be warranted but precluded by higher listing priorities; both Utah
populations were designated as candidates for listing. In Utah, the
Wasatch Front population was assigned a listing priority number of
three because the magnitude of the threats were high and imminent,
while the West Desert population was assigned a listing priority of
nine because of moderate to low threats.
On November 15, 1994, the Service published a Candidate Notice of
Review in the Federal Register for the four candidate DPSs (59 FR
58982). The listing priority for the West Desert DPS was increased from
nine to six. In the Service's September 19, 1997, Candidate Notice of
Review, the scientific and common name of the Wasatch Front, West
Desert, and Great Basin DPSs were changed to Rana luteiventris and
Columbia spotted frog respectively, based on new genetics information
(Green et al. 1997).
On November 28, 1997, the Service announced the availability of a
Draft Conservation Agreement for the Wasatch Front and West Desert
populations (Utah) of the Columbia spotted frog (Rana luteiventris) (62
FR 63375). The Service received a request to extend the comment period,
and on December 24, 1997, announced that the comment period on the
Draft Conservation Agreement had been extended until January 16, 1998
(62 FR 67398). The Service subsequently signed the Conservation
Agreement on February 13, 1998, in cooperation with the Utah Division
of Wildlife Resources (UDWR), Bureau of Land Management, Bureau of
Reclamation, Utah Reclamation Mitigation and Conservation Commission,
Central Utah Water Conservancy District, and the Confederated Tribes of
the Goshute Federation.
The goal of this interagency Conservation Agreement is to ensure
the long-term conservation of the Columbia spotted frog within its
historical range in Utah. The Conservation Agreement established a
mechanism for the recovery of the spotted frog through interagency
cooperation, coordination of conservation efforts, and development of
recovery priorities. Due to numerous activities and studies in addition
to and pursuant with the Conservation Agreement, we determined that the
status of the Columbia spotted frog in Utah had improved and no longer
warranted listing under the Act on April 2, 1998 (63 FR 16218). With
this finding, both DPSs of Columbia spotted frogs in Utah were removed
as candidates for listing on October 25, 1999 (64 FR 57533).
On June 8, 1999, a complaint was filed by the Biodiversity Legal
Foundation and Peter Hovingh challenging the not warranted finding as
violating the Act and the Administrative Procedure Act. The complaint
alleged that the not warranted finding was inconsistent with the 8
years of prior determinations by the Service; that the Wasatch Front
population of the Columbia spotted frog deserved listing under the Act;
that the Wasatch Front population of the Columbia spotted frog had
declined during the course of the 8-year administrative process; that
the Conservation Agreement contained future and voluntary actions that
had yet to be implemented and had not proven successful at protecting
the Wasatch Front population of the Columbia spotted frog; and that all
measures identified by the Service as having previously been
implemented had either failed, had been rejected by the Service as
inadequate, or were adopted to mitigate specific projects that had
already destroyed Columbia spotted frogs and their wetland and aquatic
On August 6, 2001, the plaintiffs and the Government reached a
settlement regarding this complaint. The settlement stipulated that we
remand for reconsideration the 1998 ``not warranted'' finding and start
a new status review and 12-month finding on the Wasatch Front
population of the Columbia spotted frog to be completed by July 31,
2002. The Service subsequently published a notice of intent to conduct
the 12-month finding on September 10, 2001 (66 FR 47034). The
settlement also stated that we would not vacate our previous
determination in the interim. Candidate status of this species would
not be restored unless and until we determine in the revised 12-month
finding that the species is warranted for listing, or warranted but
precluded from listing by higher priority listing actions.
Following this settlement, we initiated a review to evaluate the
status of the Columbia spotted frog on the Wasatch Front. Comments were
received, evaluated, and incorporated where appropriate into this
status review. Information included published and unpublished reports,
manuscripts, books and data, memoranda, letters, phone communications,
email correspondence, and information gathered at meetings. In
addition, persons who were species experts on the Columbia spotted frog
were provided opportunity to comment on the data used in this report to
ensure it was the most accurate and updated information available and
that it was interpreted accurately. This status review is available
upon request from the Utah Field Office (see ADDRESSES above).
The Columbia spotted frog belongs to the family of true frogs, the
Ranidae. Color and pattern descriptions of individuals from Utah
include brownish-black dorsal coloration with little to no spotting
pattern (Colburn, U.S. Fish and Wildlife Service, pers. comm. 1992).
Pigmentation on their abdomens varies from yellow to red (Turner 1957).
Columbia spotted frogs along the Wasatch Front generally possess a
salmon color ventrally, while West Desert and Sanpete County, Utah,
populations generally have a yellow to yellow-orange color ventrally.
The spotted frog is closely associated with water (Dumas 1966,
Nussbaum et al. 1983). Habitat includes the marshy edges of ponds,
lakes, slow-moving cool water streams and springs (Licht 1974; Nussbaum
et al. 1983; Morris and Tanner 1969; Hovingh 1987).
The overall distribution of the Columbia spotted frog is continuous
throughout extreme southeastern Alaska, southwestern Yukon, northern
British Columbia, and western Alberta; and south through Washington
(east of the Cascades), eastern Oregon, Idaho, and western Montana. Its
southern extent includes disjunct populations in central and
northeastern Nevada, southwestern Idaho, western and north-central
Wyoming, and northern Utah (Stebbins 1985; Green et al. 1996, 1997,
Tanner 1931, Linsdale 1940, Banta 1965, Turner and Dumas 1972, Hovingh
1993, Ross et al. 1993, 1994). These disjunct populations are highly
fragmented, occurring on isolated mountains and in arid-land springs.
Systematic and taxonomic relationships of spotted frogs occurring
in Utah to other spotted frog populations have been described in
several manners. Two subspecies of Rana pretiosa were described
originally (Thompson 1913, Wright and Wright 1949). These two
subspecies, R. p. pretiosa and R. p. luteiventris, were described based
on pigmentation characteristics of frogs. As additional specimens were
examined, variability of characteristics within and between populations
was described (Morris and Tanner 1969). Green et al. (1996) examined
allozyme and morphometric variation in R. pretiosa and suggested that
at least two species were represented, referred to as species A
(southwestern Washington and Oregon Cascades) and species B (remainder
of range). However, morphometrically the two species were ``almost
indistinguishable'' and the authors could not fully delineate the
dividing line between the ranges of species A and species B. Based on
biochemical and morphological data, Green et al. (1997) concluded that
there were two groups at the species level--Oregon spotted frog (Rana
pretiosa) and Columbia spotted frog (Rana luteiventris). They
determined that all spotted frog populations occurring within Utah
should be taxonomically described as Rana luteiventris. On September
19, 1997, the Service updated the common and scientific names of the
Utah populations to the Columbia spotted frog, Rana luteiventris.
Further analyses of taxonomic relationships among range-wide
spotted frog populations were performed by Bos and Sites (2001). This
study revealed four genetically distinct lineages. Two of these
lineages are represented in Utah--(1) the Deep Creek lineage (Deep
Creek-Ibapah population in the West Desert DPS), and (2) the Bonneville
lineage (all other populations in Utah, including the Wasatch Front and
the remainder of the West Desert DPSs). The Wasatch Front DPS appears
to have originated from the West Desert populations in relatively
recent evolutionary time, during the recession of Lake Bonneville (Bos
and Sites 2001, Toline and Seitz 1999). Therefore, genetic differences
between these populations have not yet been established. However,
separation of the West Desert and Wasatch Front DPSs is supported by
ecological and demographic distinctiveness due to geographic isolation
and habitat differences, including disparate biological, chemical, and
thermal characteristics of occupied springs and wetlands (Hovingh 1993,
U.S. Fish and Wildlife Service 1993). In addition, due to the
dependence of spotted frogs on aquatic habitats (Bos and Sites 2001)
and population isolation (Toline and Seitz 1999), there is likely no
gene flow existing between the Wasatch Front and West Desert DPSs.
The disjunct populations in Utah represent the southern extent of
the species range (Stebbins 1985). Post-glacial climatic shifts allowed
spotted frog populations to naturally distribute across drainage areas
of the Bonneville Basin of Utah. The Bonneville Basin encompasses the
area that was covered by ancient Lake Bonneville and which,
today, lies within the Great Basin province. The Great Basin province
is distinguished geologically by parallel north-south mountain ranges
separated by broad, alluvial desert basins (Christiansen 1951) and
valleys. The steep, gravelly slopes of these ranges are prominently
marked by benches and other shore features of Lake Bonneville. Springs
commonly occur at the base of the mountains (Bick 1966) and in the
valley floors. Several aquatic species have maintained an existence as
relict populations in these springs, including the Columbia spotted
frog, least chub, and several species of mollusks. However, these
species are rare and in some areas the populations are declining. Rapid
deterioration of aquatic environments, primarily from agricultural
practices, has caused other unique Bonneville Basin species, such as
Rhinichthys osculus relictus (Hubbs and Miller), a subspecies of dace,
to become extinct (Hubbs et al. 1974).
The Wasatch Front population occurs in isolated springs or riparian
wetlands in Juab, Sanpete, Summit, Utah, Tooele, and Wasatch Counties.
Columbia spotted frogs have been extirpated from the Salt Lake Valley
and tributaries to the Jordan River and Great Salt Lake due to habitat
loss from urban development. Currently, there are seven localized
populations of spotted frog that comprise the Wasatch Front population
or DPS. The largest known concentration is currently in the Heber
Valley; the remaining six locations are Jordanelle/Francis, Springville
Hatchery, Holladay Springs, Mona Springs Complex/Burraston Ponds,
Fairview, and Vernon. For purposes of this finding, each distinct area
within the Wasatch Front DPS that supports reproducing and self-
sustaining frogs is referred to as a population.
Spotted frogs are aquatic specialists and more dependent on
permanent aquatic habitats than other ranid species (Dumas 1966,
Perkins and Lentsch 1998a). The majority of sightings and captures of
this species have occurred while the frogs were submersed in water.
Range-wide, spotted frogs use a variety of habitat types including cold
water ponds, streams, lakes, and springs adjacent to mixed coniferous
and subalpine forest, grassland, and brush land (Morris and Tanner
1969, Stebbins 1985). On the Wasatch Front, they are usually found in
emergent wetlands associated with riparian or isolated spring-fed
habitat with cool and organic substrates (Dumas 1966, Morris and Tanner
1969, Cuellar 1994). Habitat usually consists of a small spring, pond,
or slough with a variety of herbaceous emergent, floating, and
submergent vegetation. Spring vegetation most commonly associated with
the spotted frog on the Wasatch Front includes: bullrush (Scirpus sp.),
sedges (Carex spp.), cattails (Typha sp.), duckweed (lemnaceae), rushes
(Juncus spp.), watercress (Nasturtium officinale), grasses (Graminae),
and algae (Ross et al. 1994). Morris and Tanner (1969) suggest that
deep silt or muck bottoms are required for hibernation and torpor.
Spotted frogs emerge from hibernation in the spring and tend to use
different habitats depending on their needs. For example, in
Yellowstone National Park sexually immature individuals tended to
inhabit aquatic habitats away from breeding adults (Turner 1958).
Breeding adults may use areas in the absence of other age-classes, and
move to sites near younger frogs as the water begins receding from the
breeding area (Turner 1958). Turner (1960) suggested that spotted frogs
have small home ranges. In Yellowstone National Park frogs were
recaptured at or near the same location used for breeding. This
hypothesis is supported by studies of spotted frogs in the Heber Valley
where most individuals were recaptured in the site of their initial
capture (Ammon and Wilson 2001).
Recent studies have evaluated spotted frog locations and movements
outside of the breeding season. Ongoing research in the Heber Valley of
Utah indicates that spotted frogs travel short distances between
breeding and post-breeding habitats, and many breeding sites serve as
year-round habitat (Ammon and Wilson 2001). Bull and Hayes (2001) noted
post-breeding dispersal distances of 15 to 560 meters (49 to 1,837
feet) in spotted frogs in northeastern Oregon. Dispersal patterns were
related to pond size, water temperatures, and proximity to other
sources of permanent water. Dispersal corridors are typically limited
to aquatic or semi-aquatic habitats such as streams, intermittent
drainages, and seeps (Ross and Peterson 1998). Intensive mark-recapture
and radiotelemetry studies are needed to determine actual movement
distances and patterns in this and other Utah populations.
Wasatch Front populations begin breeding in early-March with the
spring thaw. However, populations at higher elevations may delay
breeding until mid-March, and continue through late-April (UDWR data on
file). Elevation differences in spotted frog breeding seasons have been
similarly reported in British Columbia (Licht 1975) and Yellowstone
National Park (Turner 1958), and are attributed to temperature
differences. Spotted frogs are known to use temporary bodies of water
for breeding in more mesic parts of their range (Turner 1960, Licht
1971), but in Utah breeding sites are predominantly associated with a
spring or some other permanent water source (Morris and Tanner 1969,
Hovingh 1993, Ross et al. 1993, Ross et al. 1994).
Egg deposition is stimulated by a single pair of frogs followed by
other spotted frogs depositing eggs in the same area. It has been
reported that they will deposit eggs in the same area annually (Morris
and Tanner 1969, Nussbaum et al. 1983). Individual females may oviposit
more than one clutch of eggs annually (Morris and Tanner 1969);
however, this has not been confirmed in Utah populations. Sex ratios
have not been quantified in Utah. For estimates of effective population
size (Ne), UDWR used estimates of 1:1 sex ratios as derived
from egg mass monitoring information during 1991-1993 surveys (Ross et
al. 1993, 1994).
Egg masses tend to be deposited in open, shallow (<20 centimeters/
7.9 inches) areas within 2 meters (6.6 feet) of the shoreline with
water temperatures ranging between 11 deg.C and 20 deg.C (51 deg.F and
68 deg.F) (Ross et al. 1993, 1994). Egg masses are weakly adhesive and
form an irregular mass or globular cluster approximately 7.5 to 20
centimeters (3 to 8 inches) in diameter. They may become weakly
attached to vegetation (Chara spp.) for a short period of time.
Eventually the mass floats to the surface, exposing the top layer of
eggs. Wind and water currents often move masses around and they may
begin to break up. Eventually the egg masses may become separated and
covered with debris. Number of eggs per egg mass are quite variable,
ranging from 147 to 1,160 eggs (Toone 1991). Individual eggs are
typically larger than those of other ranids. Hatching rates vary
directly with water temperature (Toone 1991).
Studies in Montana, Oregon, and British Columbia have documented
that insects are the primary prey for the spotted frog (Miller 1978,
Whitaker et al. 1982, Licht 1986). These studies were performed in
portions of the species range outside of Utah where spotted frogs
inhabit different habitat types and may exhibit different life history
characteristics. However, absent site-specific information, we can
assume that the feeding habits of spotted frogs in Utah are similar to
those documented in other areas.
Summary of Factors Affecting the Species
Section 4 of the Act and implementing regulations (50 CFR part 424)
set forth the procedures for adding
species to the Federal lists. 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. An endangered species is one
that is in danger of extinction throughout all or a significant portion
of its range. A threatened species is one which is likely to become and
endangered species within the foreseeable future throughout all or a
significant portion of its range. The five factors used in determining
whether a species warrants listing as either threatened or endangered
and their application to the Wasatch Front Columbia spotted frog (Rana
luteiventris) are as follows:
A. The Present or Threatened Destruction, Modification, or Curtailment
of its Habitat or Range
Urban growth with its associated water development and consequent
losses of wetland and spring habitats were the primary causes for
historical population losses and habitat fragmentation for the spotted
frog on the Wasatch Front. Continued urbanization has been identified
as a potential cause of concern for the spotted frog based on growth
projections. The Wasatch Front human population is projected to
increase to almost 3 million people by 2020 and 5 million by 2050 (Lee
2001). Counties with extant populations of spotted frogs are
experiencing high human population growth rates (Table 1).
Approximately 14,400 hectares (35,500 acres) of wetland habitats
are at direct risk from urban expansion by 2050 (Lee 2001, Lee and
Melcher 2001). Development is projected to occur near most extant
spotted frog populations by 2050. Urban development is not projected to
occur in the vicinity of the Jordanelle/Francis population; however,
recreational and rural residential development is increasing in the
area and will likely continue. However, in and of themselves, general
predictions about the degree of urbanization and other land uses in
2050 are too distant in time and speculative in nature to support a
finding that the spotted frog is likely to be in danger of extinction
in the foreseeable future. Though three of the populations once faced
more certain and immediate threats to their habitat, as discussed
below, those threats have been sufficiently addressed by conservation
actions currently in place.
Table 1.--Projected Annual Growth Rates of the Human Population in
Counties With Extant Populations of Spotted Frog
Note: Growth rates taken from Lee 2001 except for Summit County which
was obtained from the web site, URL: http://utahreach.usu.edu/summit/
Recent conservation and management efforts (Table 2) have
successfully focused on addressing foreseeable habitat loss threats to
an extent that alleviates the threat of urbanization at the extant
populations. Water development was identified as negatively impacting
spotted frog habitat in the Heber Valley. However, this threat was
removed with the purchase of 125 cubic feet per second of riverine base
flows and 650 acre-feet of water for restored habitats under the Provo
River Restoration Project. A potential threat to the Mona/Burraston
population of spotted frogs is groundwater withdrawals in the Juab
Valley. Thiros (1999) estimated, using 1992 water withdrawal rates and
assuming no additional water contributions to the system, the water
table could be lowered by 1.5 m (5 ft) and groundwater discharge rates
reduced by 38 percent by 2022. However, model predictions indicate that
the groundwater level available to support wetland vegetation will not
significantly decrease in the Mona/Burraston area (Thiros 1999) and
habitat for this population of spotted frogs is not likely to be
affected. Groundwater levels are currently sufficient to sustain the
Mona/Burraston spotted frog population. Habitat acquisitions or
easements have been completed to a large degree at three of the extant
populations (Mona/Burraston, Heber Valley, Springville Hatchery) to
protect the populations in perpetuity. For example, 85 percent of the
Provo River corridor in the Heber Valley (including most occupied
spotted frog habitat) has been purchased through conservation efforts
and is protected in perpetuity through legally binding agreements.
Because of this protection, urbanization is no longer a direct threat
to these populations. Although the threats to the habitat of other
populations are distant and speculative at this time, as discussed
below in ``Recommendations for the Future,'' similar protection efforts
are planned for those populations.
Due in large part to habitat protection and conservation activities
put in place during the past 5 years, the long-term viability of the
Columbia spotted frog population on the Wasatch Front is stable to
increasing. Recent survey efforts have discovered new breeding sites
over larger areas, and documented larger population sizes than were
previously known. The extant populations are more extensive, more
connected and, therefore, more viable than previously thought.
Although habitat acquisitions that are completed are sufficient to
address the current threats to the Wasatch Front population of spotted
frog, efforts continue for acquiring additional habitats. Habitat
acquisitions, to date, were targeted in those populations where threats
were the most imminent. Potential threats are minimal at the remaining
unprotected populations and do not currently compromise the long-term
persistence of the spotted frog.
Given the habitat protection already in place, habitat loss is not
likely to put the frog in danger of extinction in the foreseeable
future. This is so even if none of the additional planned habitat
protection is completed. To the extent that the additional protection
is completed, it should further improve the status of spotted frog.
Table 2.--Habitat Protection at Extant Spotted Frog Populations
Subunit or population Habitat quantity easement Habitat type Purchase status
Springville Hatchery............ 22.3 ha (55 ac).... Acquisition (State Occupied spring Completed
fish hatchery). complex.
Mona/Burraston.................. 34.6 ha (85.5 ac).. Acquisition........ Occupied spring Completed
Mona/Burraston.................. 7.9 ha (19.5 ac)... Acquisition or Occupied spring Ongoing
Heber Valley.................... 251 ha (620 ac).... Acquisition........ Occupied riparian Completed
Heber Valley.................... 198 ha (490 ac).... Acquisition........ Occupied riparian Ongoing
Heber Valley.................... 650 acre-feet (plus Acquisition........ Stream flows to Completed
125 cfs base occupied riparian
Jordanelle/Francis.............. 9.7 km (6 mi), 6.5 Easement........... Occupied riparian Ongoing
ha (16 ac). wetlands.
Fairview........................ 162 ha (400 ac).... Easement........... Occupied spring Ongoing
Utah Lake....................... 5,544 ha (13,700 Acquisition........ Unoccupied spring Completed
ac) (includes complexes.
Weber River..................... 3.2 km (2 mi)...... Acquisition........ Unoccupied Completed
* A full list of all actions since 1998 (e.g., habitat enhancements, surveys, conservation easements) is in the
appendix of this Status Review.
B. Overutilization for Commercial, Recreational, Scientific, or
The collection of spotted frogs is currently prohibited (State of
Utah Rule R657-3). However, past collections of this species may have
contributed to the extirpation of some populations on the Wasatch
Front. In particular, spotted frogs were collected from the Provo,
Springdell, and Vivian Park areas for universities (U.S. Fish and
Wildlife Service 1993).
Past and ongoing studies on the life history and habitat
requirements of spotted frog in Heber Valley include the use of radio-
tags, PIT-tags, and general handling of individual frogs. However,
there have been no documented injuries or mortalities due to research
related activities (e.g., handling stress). Although these actions may
increase the stress, disease risk, and mortality in this population,
these studies are not a significant threat with the operating protocols
and procedures to limit potential impacts in place.
C. Disease or Predation
Predation by introduced species is a potential threat to the
Wasatch Front spotted frog. Most spotted frog habitats in Utah were not
historically inhabited by predatory fish species (Sigler and Miller
1963). Today, a variety of introduced fishes, including largemouth
bass, rainbow trout, brown trout, brook trout, common carp,
mosquitofish, and rainwater killifish have become established in
spotted frog habitats on the Wasatch Front. The potential threat
appears highest from mosquitofish due to its affinity for the same
systems as the spotted frog.
The mosquitofish (Gambusia affinis) is a small fish native to the
eastern and southeastern United States. This species has been stocked
throughout the world as a means of biological control for mosquitos
(Sigler and Sigler 1996). Mosquito abatement districts have extensively
stocked mosquitofish throughout various aquatic habitats in Utah
including wetlands that have current or historic populations of spotted
frog. Mosquitofish may be illegally transferred to new habitats by the
general public or inadvertently transferred during relocation and
reintroduction efforts for other aquatic species. Once introduced,
mosquitofish can migrate to adjacent habitats.
Mosquitofish pose a potential threat to spotted frogs because of
their known aggressive predation on eggs and young of fishes and
amphibians (Grubb 1972, Sigler and Sigler 1987). Mosquitofish are
suspected to prey preferentially on amphibian larvae in the presence of
other potential prey items (Goodsell and Kats 1999). Spotted frogs may
be particularly susceptible to predation by mosquitofish because the
frogs emerge from the egg at a very small size of 8-10 millimeters
(Morris and Tanner 1969). Studies of the California red-legged frog
(Rana aurora draytonii) showed that tadpoles of all sizes may be
susceptible to mosquitofish predation; they found that mosquitofish
were effective predators on tadpoles and could injure or kill tadpoles
larger than themselves (Courtenay and Meffe 1989). Spotted frog larvae
are unable to swim for a few days after hatching, thus inhibiting their
ability to actively avoid predation (Morris and Tanner 1969).
Mosquitofish have been observed preying on recently emerged spotted
frog tadpoles in populations on the Wasatch Front (Ross et al. 1993;
Chris Keleher, CUWCD, pers. comm.).
Raccoons expanded their range into Utah over the past 25 years
(Wilson and Balcomb 2001). Raccoon predation has been documented in the
Heber Valley (K. Wilson, UDWR, pers. comm.). Although they are
amphibian predators, the level of threat to the Wasatch Front spotted
frog has not been determined. Bullfrogs, another nonnative predator,
also are expanding their range into the Wasatch Front, but have not
been documented in any spotted frog populations.
To date, no spotted frog extirpations have been attributed to the
presence of nonnative species. Population-level effects (i.e.,
population declines due to predation) by mosquitofish, and other
predators, have not been observed on the Wasatch Front (K. Wilson pers.
comm.). Available information suggests that spotted frogs are
persisting with the presence of nonnative species. Based on numbers of
breeding sites and egg masses, extant spotted frog populations are
stable to increasing.
Habitat protection and research efforts are continuing to explore
control methodologies in the event that nonnative species could
ultimately affect spotted frog populations. For example, newly created
and restored habitats at Heber Valley and Jordanelle/Francis are being
designed to prevent nonnative species invasions. Ongoing conservation
actions at all occupied habitats include assessing the impacts of
nonnative species on the spotted frog and active removal in some cases.
For example, a mechanical removal effort targeting nonnative fish
species (primarily mosquitofish) has been underway since 1999. Long-
term reduction of mosquitofish was not achieved; however, the
documented temporary reduction has important implications toward
substantially reducing mosquitofish numbers during critical life-stages
of spotted frog (recently emerged tadpoles) and allowing better
recruitment of spotted frog to adult life-stages (UDWR, unpubl.data).
Given the known level of impact and the above-described conservation
actions and protocols, predation by nonnative species does not threaten
the persistence of Wasatch Front spotted frog populations.
Chytrid fungus was recently discovered in the Heber Valley
population of the spotted frog (Green and Converse 2002, Green and Sohn
2002). Chytrid fungus has been implicated in precipitous declines of
amphibian species worldwide (Berger et al. 1998, Longcore et al. 1999,
Fellers et al. 2001, NWHC 2001). However, its role in the larger
picture of frog population
dynamics, and more importantly, its implications for the spotted frog
remains undefined. In fact, questions remain regarding the actual
infection rate of chytrid in wild populations (Sredl 2000). Some
researchers now speculate that the distribution and infection rate of
chytrid may reflect more the extent to which biologists have tested for
it as much as it reflects the actual distribution of infection (Fellers
et al. 2001). Chytrid fungus may naturally occur in many amphibian
populations that are only affected when other stressors or
environmental factors interact synergistically to increase the
virulence of the disease or compromise amphibian immune systems (Carey
et al. 1999, Lips 1999). Some frog populations are known to have
coexisted with chytrid fungus for decades (USFWS 2002).
Some researchers speculate that the spotted frog may exhibit a
resistance (David Green pers. comm. 2002) or adapt (Green and Converse
2002, Green and Sohn 2002) to chytrid infection. Evidence suggests that
amphibians infected with chytrid frequently die of dehydration because
alteration of the skin inhibits their ability to absorb water. This is
especially true in toads which, as opposed to frogs, have a limited
area of skin over which to uptake water (i.e., the pelvic patch);
chytrid die-offs have been seen much less frequently in more aquatic
amphibians, such as salamanders. Researchers hypothesize that frogs
avoid death by dehydration from chytrid infection because they more
freely exchange water though skin over a large portion of their body.
In this sense, spotted frogs, because they are highly aquatic in
nature, may exhibit a similar ``resistance'' to chytrid infection
(David Green pers. comm. 2002). The infected Heber Valley frogs
exhibited a limited infection with chytrid present only on the toes;
these individuals appeared to control and adapt to their chytrid
infections (Green and Converse 2002, Green and Sohn 2002). The chytrid
researchers believe that low-stress conditions in the laboratory may
have allowed these spotted frogs to persist long after infection was
The Heber Valley population is the largest and most protected
spotted frog population on the Wasatch Front. Habitat protection and
conservation efforts have minimized or removed potential threats such
as urbanization, predation, and water depletion as stressors from this
population. Based on available information, the Heber Valley frogs are
less likely to incur large-scale die-offs and are more likely to
coexist with chytrid fungus in this low-stress environment. To prevent
the potential for further spread of chytrid and other potential disease
risks for spotted frogs, the UDWR has implemented strict disease
protocols for managers and researchers working with spotted frog and
other aquatic species in Utah. Implementation of these procedures is
expected to greatly decrease the potential for chytrid to spread to
other spotted frog populations. However, all Wasatch Front spotted frog
populations will be closely monitored to identify any potential effects
Our current understanding and the relatively low level of known
infection of chytrid fungus provides a measure of assurance that the
current infection will not put the spotted frog in danger of
extinction. To ensure the accuracy of this analysis, efforts will be
made to continue to document and control the spread of chytrid fungus.
D. The Inadequacy of Existing Regulatory Mechanisms
Regulatory mechanisms did not halt the historical decline of the
spotted frog along the Wasatch Front. However, historically, this was
largely due to a lack of knowledge regarding the declining status of
the spotted frog. Beginning in the mid-1990s, conservation of the
spotted frog became a focus of many State and Federal agency efforts,
resulting with implementation of the interagency Conservation Agreement
and long-term protection for extant spotted frog populations.
Importantly, the extant populations are now largely protected from
imminent threats and there are ongoing conservation actions aimed at
providing long-term protection for unoccupied habitats.
Existing regulatory mechanisms that also may provide protection for
spotted frogs and their habitats include--(1) State laws, (2) National
Environmental Policy Act, and (3) section 404 of the Clean Water Act.
These laws provide additional protection and awareness above and beyond
completed and ongoing conservation efforts.
The spotted frog is currently designated as a sensitive species in
the State of Utah and is managed under a Conservation Agreement. State
of Utah Rule 657-3 regulates the collection, importation, and
possession of spotted frogs. The State of Utah Fish Stocking and
Transfer Procedures (Policy W2ADM-1) protects the spotted
frog and other sensitive species in Utah by preventing the stocking of
nonnative and other potentially harmful species in spotted frog
habitats, and outlining protocols to decrease potential transmission of
harmful pathogens to spotted frog populations.
National Environmental Policy Act
The National Environmental Policy Act (NEPA) requires Federal
agencies to describe a proposed action, consider alternatives,
identify, and disclose potential environmental impacts of each
alternative, and involve the public in the decision-making process.
Federal agencies are not required to select the alternative having the
least significant environmental impacts, but environmental impacts,
including those to wetlands and wildlife, are included as part of the
public review process and NEPA analysis.
The NEPA can be an effective mechanism in the conservation of the
spotted frog where a Federal nexus exists, and agencies are actively
involved in spotted frog conservation; i.e., the Conservation Agreement
provides a mechanism for coordination and awareness in this regard.
Land use and activities on private lands which includes more than half
of the spotted frog populations are not required to comply with NEPA.
Many large-scale land activities and water development projects
occurred before there was a local awareness about the historically
declining status of the spotted frog. However, most Federal agencies
with interest or planned actions that might affect spotted frog are
currently signatories to the Conservation Agreement. Although their
involvement in and of itself does not legally bind the signatories to
specific actions under NEPA, since the inception of the agreement these
agencies have included spotted frog impacts and conservation as part of
Clean Water Act Section 404
Section 404 of the Clean Water Act, administered by the
Environmental Protection Agency and the Army Corps of Engineers, is the
primary Federal law that potentially provides protection for the
spotted frog by regulating fill to wetlands and other aquatic habitats
determined to be ``jurisdictional,'' in part through proximity to
surface water connections. The types of wetland impacts addressed by
section 404 include:
(1) Actions that impact jurisdictional wetlands defined as ``waters
of the United States,'' 33 U.S.C. Sec. 1363(7);
(2) Discharge of dredged or fill material into waters of the United
(3) Limited activities in upland habitats that may have indirect
to adjacent wetlands where fill is permitted.
Recent court decisions (National Mining Association v. U.S. Army
Corps of Engineers 145 F.3d-1399 (D.C. Cir. 1998) (overturning the
Tulloch Rule); Solid Waste Agency of Northern Cook County v. United
States Army Corps of Engineers 531 U.S. 159 (2001) (narrowing the
definition of waters of the United States)) have recently reduced the
authority of section 404 to protect wetland habitats.
Because of their hydrologic connection to navigable waterways
(e.g., Provo River, San Pitch River), the Corps still regulates the
remaining unprotected remnant spotted frog wetland areas and large
areas of unoccupied habitats. The Service maintains an important
advisory role to the Corps in the section 404 permitting process.
Because of questions concerning the success of spotted frog
translocations and spotted frog habitat creation, recent discussions
with the Corps have focused on using habitat protection (acquisitions,
easements) and restoration techniques for mitigation of spotted frog
habitats where necessary.
Resource agencies have been successful at incorporating actions and
project conditions that protect and enhance spotted frog habitat.
Ongoing efforts include the protection and restoration of spotted frog
habitat along the upper Provo River associated with the proposed
Victory Ranch development and planned acquisitions of other properties
along the Upper Provo River. In addition, ongoing negotiations have
been successful in relocating a proposed wastewater treatment plant in
the San Pitch Valley near Fairview to a location outside of spotted
frog habitat. Furthermore, the applicant is proposing to donate
approximately 1.6 hectares (4 acres) of mixed uplands and wetlands for
a conservation easement for spotted frogs as a part of the project.
Some areas of unoccupied habitats may be considered
nonjurisdictional, i.e., not subject to regulations under section 404.
However, a large portion of remaining unoccupied habitats are not
imminently threatened, and some unoccupied suitable habitats, like
those at Utah Lake and the Weber River, are protected in perpetuity.
Unoccupied habitats are important for future reintroduction and range
expansion efforts now that the extant populations are stable. Although
there are no documented records of spotted frogs in these areas, Utah
Lake and the Weber River fall within its historic range and provide
presumably suitable habitat.
In summary, section 404 certainly does not provide complete
protection for the spotted frog and its habitats. Historically,
regulatory inadequacies likely resulted in the loss of large amounts of
occupied spotted frog habitats. Agencies have more recently been
successful in working with local landowners and the 404 permitting
process to protect and restore spotted frog populations and habitat.
The cooperative environment that has resulted from the Conservation
Agreement has facilitated efforts to prioritize the spotted frog
through the section 404 permitting process. Because of this emphasis,
actions that could affect occupied spotted frog habitats are more
thoroughly evaluated and efforts are made to avoid or minimize
potential impacts. Therefore, potential regulatory inadequacies do not
threaten the long-term persistence of the Wasatch Front spotted frog.
E. Other Natural or Manmade Factors Affecting its Continued Existence
Drought may play a role in reducing reproduction of spotted frogs
on the Wasatch Front. Decreased rain and snowfall can dry wetlands,
dessicate spotted frog egg masses and larvae, and reduce survival rates
of subadults and adults (U.S. Fish and Wildlife Service 2000). The
combination of increased water demands and natural drought cycles may
further reduce the extent and quality of spotted frog habitat and the
size of the remaining populations on the Wasatch Front.
Contaminants have not been specifically implicated in the decline
of any spotted frog population on the Wasatch Front. However, given the
prevalence of agriculture and urban development, the species is likely
exposed to a variety of toxins from urban and agricultural sources.
While the sensitivity of this species is largely unknown, studies of
similar amphibian species show sublethal and lethal effects at the
These factors are not currently known to be significant threats to
the long-term persistence of the Wasatch Front spotted frog.
Conclusions and Findings
Currently, there are seven populations of spotted frog included in
the Wasatch Front DPS, including the newly discovered Vernon population
in the Rush Valley near the town of Vernon. Survey efforts since 1999
have greatly expanded the known range of most populations. Most
notably, approximately 19 kilometers (12 miles) of occupied spotted
frog habitat were discovered in the upper Provo River corridor. All
extant populations, with the exception of the very small, isolated
Springville Hatchery/T-Bone Bottom population, have either increased
(documented colonization of unoccupied newly created or restored sites)
or have been found to be of a larger population size (additional
occupied sites or greater density of sites found within known
population boundaries) than previously thought (Table 3).
Table 3.--Numbers of Documented Breeding Sites in Spotted Frog Populations on the Wasatch Front
1994 1995 1996 1997 1998 1999 2000 2001 2002
Jordanelle/Francis...................... 14 14 14 14 14 23 23 33 48
Heber Valley............................ 22 23 33 52 56 57 74 74 91
Springville Hatchery/T-Bone Bottom...... 3 3 3 3 3 3 3 3 3
Burraston Ponds/Mona Springs Complex.... 4 4 4 4 4 7 7 7 7
Holladay Springs........................ 2 2 2 2 2 4 4 4 4
Fairview................................ 11 11 11 11 11 13 26 26 26
Vernon.................................. ...... ...... ...... ...... ...... ...... ...... ...... 1
The Springville/T-Bone Bottom remains the most vulnerable to
extirpation. All other populations (Heber Valley, Jordanelle/Francis,
Mona/Burraston, Holladay, and Fairview) have exhibited stable or
increasing egg-mass trends based on a review of almost 10 years of egg-
mass number data. Populations, however, are
cyclic and exhibit continuous, natural high/low fluctuations.
Population declines are not unusual; amphibian populations are
naturally dynamic, and exhibit sporadic breeding in response to
environmental stressors (Duellmann and Trueb 1986).
Population fluctuations (as evidenced by egg mass numbers) have
occurred, but have been attributed to natural population dynamics
resulting largely from climatic conditions, and not the result of
changed landscape conditions. In addition, the Vernon population was
discovered in 2002. This discovery and that of an additional 19
kilometers (12 miles) of occupied habitat along the Provo River
(Jordanelle/Francis population) implies that additional populations and
occupied habitat could yet be discovered.
Based on this recent data, extant populations of the Wasatch Front
spotted frog DPS, after decades of decline, have been exhibiting a
stable to increasing trend in the most recent time period examined
(from 1998 to present; Table 4, Table 5).
Table 4.--Numbers of Egg Masses at Documented Breeding Sites in Spotted Frog Populations on the Wasatch Front
1994 1995 1996 1997 1998 1999 2000 2001 2002
Jordanelle/Francis............. 92 79 29 21 21 20 59 31 44
(63) (99) (165) (260)
Heber Valley................... 120 156 323 219 176 206 151 123 206
(167) (473) (491) (372) (438) (431) (418) (550)
Springville Hatchery/T-Bone 7 6 0 65 87 44 50 25 9
Burraston Ponds/Mona Springs 5 66 63 148 78 61(78) 111P 69 41
Complex....................... (120) (73) (41)
Holladay Springs............... 24 33 29 64 122 144 135 52 27
(192) (160) (68) (27)
Fairview....................... 35 34 24 24 22 17 59 20 * 8
(25) (130) (163) (86)
Vernon......................... ....... ....... ....... ....... ....... ....... ....... ....... 4
() = egg masses at original breeding site + egg masses at recently discovered breeding sites.
* Three of 11 sites were not surveyed because access was mistakenly denied to the property. This situation has
been corrected and full access to these sites has been restored.
Table 5.--Summary of Spotted Frog Population Trends
Time period Number of populations Population stability/size
Pre-settlement........................... 18 \a\ No data.
Early to Mid 1900s....................... 18 \a\ Presumed decreasing.
Up to 1993............................... 9 Documented decreased.
1995 to 1998............................. 6 Stable.
1998 to 2002............................. 7 \b\ Stable to increasing.
\a\ Includes documented historic and current populations. Current populations are assumed to have been present
\b\ Includes recently discovered Vernon population.
The recent change in species status and trends is due in part to
our increased knowledge of the species distribution and in part due to
the success of already-completed conservation efforts that have
minimized or reduced many of the imminent threats to extant
populations. Although not all actions necessary to alleviate concerns
have been completed, completed conservation actions have addressed and
removed or sufficiently reduced threats and the risk of extinction.
The development and implementation of the Conservation Agreement
represented an important shift in awareness and effort for conservation
of the Wasatch Front spotted frog. Since the initiation of the
Conservation Agreement in 1997-1998 and the subsequent conservation
actions, monitoring and survey data has shown that populations are
larger than previously thought.
Conservation actions have been successful at addressing localized
threats to the species at the extant population areas. For example,
habitat protection and removal of grazing at Mona Springs has resulted
in significant improvements to spotted frog habitat. Habitat
acquisitions specific for existing spotted frog populations have
occurred (e.g., Heber Valley and Mona/Burraston) and significant
acreages of unoccupied historic habitat have been purchased and
protected (e.g., Utah Lake Wetland Preserve) as mitigation for prior
impacts to aquatic resources associated with the Central Utah Project.
Funds also have been allocated for research into the life history,
habitat requirements, and genetics of the spotted frog.
Specific conservation actions and large-scale land acquisitions
have occurred that may provide reintroduction areas for spotted frog
range expansion efforts. For example, acquisition of the Utah Lake
Wetland Preserve and parcels in the Weber River drainage to provide
historical, but currently unoccupied habitats.
Of the extant populations, there is a range of ecological size and
function that provides a level of diversity. Some populations occur
along riparian wetland corridors while others occupy complex spring
systems in the valley floor. Although populations are undoubtedly
smaller than they were historically, most exhibit stable or increasing
trends. The Heber Valley, Jordanelle/Francis, Fairview, and
possibly the Mona/Burraston population are large enough to provide some
small scale metapopulation function (genetic and demographic buffer)
within individual population boundaries. Although not discrete
populations, these locations occur over a geographic area of sufficient
size and habitat diversity to yield localized genetic interchange.
These sub-population dynamics provide local genetic and demographic
buffer for the overall population. Other populations like the
Springville and Holladay populations, provide small, isolated genetic
and demographic refuge and a locally unique ecological function to the
Wasatch Front DPS.
There is no specific answer in conservation literature as to the
number of populations necessary to allow long-term persistence of a
species in a natural evolutionary trajectory. For amphibians, most
experts agree metapopulation dynamics provide a critical role in
population stability. In the absence of large, connected
metapopulations, multiple spotted frog populations of different sizes
that represent a range of natural ecological function can provide a
reasonable level of assurance for long-term persistence of the species.
Newly created or isolated small populations can provide demographic and
genetic refuge for other populations. Larger, better connected
populations can prevent loss of genetic diversity and prevent
detrimental genetic affects that can occur in small populations.
The number of extant populations is one factor affecting the
viability of a species. The greater number of populations that occur,
the less likely the species will go extinct. This also can be
misleading. One large metapopulation fragmented into two smaller
populations by human impacts does not translate into a greater chance
of persistence. Other factors, such as population size (relative
density, abundance, or effective size) and stability (protection of
habitat, stable or increasing trend in monitoring data) must be
considered in concert with number of populations. When there is a
positive or stable trend in population size and numbers and a reduction
in threats due to completed and ongoing conservation actions, the
species is likely to persist into the future.
The overall level of threats to the long-term persistence of the
Wasatch Front spotted frog has decreased in recent years, particularly
since 1998. Although most of the human activities that contributed to
these threats still occur to some extent throughout the Wasatch Front,
there is no longer the same level of impacts on the spotted frog that
resulted in past wide-spread habitat destruction and the loss of
spotted frog populations. Much of the occupied habitat for the spotted
frog is under State or Federal ownership and ongoing management of
these lands emphasizes the long-term persistence of the spotted frog.
This is not to say that threats have been eliminated. Localized areas
continue to be affected by specific problem activities.
However, mechanisms are in place through Federal, State, and local
conservation and land-use plans to identify these activities, correct
the problems, and protect spotted frog populations. To date, these
actions have been successful at reducing threats to extant populations,
largely by acquiring important habitats and implementing management
actions that improve habitat conditions. Success is evidenced by the
stable to improving status of the spotted frog throughout the Wasatch
Front in the most recent time period evaluated.
Based on this analysis of the effects of conservation actions
already in place, the trajectory of the Wasatch Front spotted frog
status continues to be towards more secure populations, reduced
threats, and improved habitat conditions. Although some threats
continue and may increase, most threats have been or are being
addressed through completed or ongoing actions and at this time do not
threaten the long-term persistence of the spotted frog. Our analysis of
the five factors under section 4(a)(1), individually and collectively,
indicates that the spotted frog is not in danger of extinction or
likely to become in danger of extinction in the foreseeable future
throughout all or a significant portion of the Wasatch Front.
Therefore, the Service finds that the Wasatch Front spotted frog is
``not warranted'' for listing under the Act. If new information
indicating that the level of threats have become more severe or the
status of the spotted frog or its habitat degenerates in the future,
the status of the spotted frog will be reevaluated.
Recommendations for the Future
Following historical habitat and population losses, the current
populations are stable to improving and most are protected to a large
degree from ongoing direct habitat loss, due to already completed
conservation actions. Further habitat acquisitions and protections are
in progress for the Jordanelle/Francis, Heber Valley, Mona/Burraston,
and Fairview populations. Current ventures are focused on acquiring
habitat easements along approximately 9.7 kilometers (6 miles) above
Jordanelle Dam, including occupied and suitable spotted frog habitats.
Easements are currently being pursued with 7 Fairview landowners to
protect approximately 162 hectares (400 acres) of occupied spotted frog
habitat and migration corridors from potential water and residential
development. The remaining 15 percent of the Provo River corridor in
the Heber Valley is projected to be purchased and protected by 2004. In
the Mona/Burraston population, fee-title purchase or conservation
easements are currently being negotiated for 7.9 hectares (19.5 acres)
which would allow for protection of all spring and potential spotted
frog habitat on this site.
Completion of habitat protection activities which have resulted in
a reduction of threats to the extant populations allows conservation
efforts to now focus on population expansion into historic, unoccupied
habitats. Habitat protection and reintroduction of frogs into suitable,
unoccupied habitats will further improve the long-term status of the
species along the Wasatch Front. For example, recent habitat
acquisitions that also will benefit the spotted frog include 5,544
hectares (13,700 acres) at Utah Lake and 3.2 kilometers (2 miles) along
the upper Weber River.
Therefore, the focus of spotted frog conservation efforts can
reasonably shift to acquisition of additional occupied and unoccupied,
suitable habitats and range expansion efforts, including:
(1) Land protection mechanisms, such as conservation easements and
fee-title acquisitions generally provide the most long-term benefits
for sensitive species. Voluntary conservation actions on parcels of
private land may provide site-specific benefits to the frog. Future
conservation should continue to focus on land acquisition and easements
that include buffer zones sufficient to minimize direct and indirect
impacts from land use as well as protection and maintenance of
dispersal or migration corridors. Furthermore, steps should be taken to
protect water sources (i.e., Juab Valley) where potential threats are
(2) Although there is no specific number of populations necessary
to prevent extinction, reintroduced populations provide ecological
redundancy in ecological function and genetic and demographic
stochasticity. There are several habitats already identified which may
provide suitable reintroduction sites. Future conservation should
include reestablishment of spotted frog populations, and associated
and land management necessary to maintain new populations in: (1) Areas
where populations previously occurred if suitable habitat remains and
(2) other suitable habitat within the natural range of the species.
(3) Some Wasatch Front spotted frog populations are notably small
in size and vulnerable to risks of detrimental genetic processes
(inbreeding, loss of genetic diversity) and demographic uncertainty.
Springville Hatchery/T-Bone Bottom population is particularly
vulnerable based on its current size and decreasing trend. Actions
should be taken to augment or through some other process, increase the
size of this population. Furthermore, the current trend should be
evaluated to determine if specific land or water use activities are
exacerbating the decrease. If specific threats are identified, priority
should be placed on reducing these threats such that the population
would remain secure into the future.
A complete list of all references cited is available upon request
from the Utah Field Office (see ADDRESSES above).
The primary authors of this document are Jessica Gourley and Laura
Romin (see ADDRESSES above).
The authority for this action is section 4(f) of the Endangered
Species Act, 16 U.S.C. 1533(f).
Dated: August 23, 2002.
[FR Doc. 02-22160 Filed 8-29-02; 8:45 am]
BILLING CODE 4310-55-P