(DRAFT) - Taxonomy
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
TAXONOMY
NAME - TOAD, WYOMING
OTHER COMMON NAMES - TOAD, WYOMING; TOAD, DAKOTA; TOAD, CANADIAN; TOAD and MANITOBA
ELEMENT CODE -
CATEGORY - Amphibians
PHYLUM AND SUBPHYLUM - CHORDATA,
CLASS AND SUBCLASS - AMPHIBIA,
ORDER AND SUBORDER - ANURA,
FAMILY AND SUBFAMILY - BUFONIDAE,
GENUS AND SUBGENUS - BUFO,
SPECIES AND SSP - HEMIOPHRYS, BAXTERI
SCIENTIFIC NAME - BUFO HEMIOPHRYS BAXTERI
AUTHORITY -
TAXONOMY REFERENCES -
Taxonomy - 1 (DRAFT) - Taxonomy
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
COMMENTS ON TAXONOMY -
Wyoming Toad
Bufo hemiophrys baxteri Porter, 1968
KINGDOM: Animal GROUP: Amphibian
PHYLUM: Chordata CLASS: Amphibia
ORDER: Anura FAMILY: Bufonidae
Adult length about 55 mm, females slightly larger than males.
Dorsal surface of body with round warts. Cranial crests fusing
medially to form an elongate boss, either a ridge with a median groove
or paired parallel ridges. The boss often cornified. Postorbital
ridges indistinct or absent. Tympanum round, smaller than the eye.
Cutting tubercles on the hind foot well developed. Background color
dark brown, gray or greenish, with small dark dorsal blotches and a
median light stripe. Belly spotted; mature males with a dark throat.
Distinguished from Bufo americanus, Bufo fowleri and Bufo woodhousei
by its smaller size and the fused cranial crests (02).
Other common names for the Wyoming toad include: Canadian toad,
Dakota toad, and Manitoba toad.
Type specimens, U.S. Nat. Museum (01). Additional specimens,
University of Wyoming Zoology Museum; University of Kansas Museum of
Zoology.
Taxonomy - 2 (DRAFT) - Status
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
STATUS
Coded Status
E: Federal Endangered
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Wyoming toad (Bufo hemiophrys baxteri) has been designated as
Endangered pursuant to the Endangered Species Act of 1973 (50 CFR
17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C. 1531-1540), as amended.
The subspecies has this status wherever found including the State of
Wyoming.
This species is protected by the Lacey Act (P.L. 97-79, as
amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to import,
export, transport, sell, receive, acquire, or purchase any wild animal
(alive or dead including parts, products, eggs, or offspring):
(1) in interstate or foreign commerce if taken, possessed,
transported or sold in violation of any State law or
regulation, or foreign law; or
(2) if taken or possessed in violation of any U.S. law,
treaty, or regulation or in violation of Indian tribal law.
It is also unlawful to possess any wild animal (alive or dead
including parts, products, eggs, and offspring) within the U.S.
territorial or special maritime jurisdiction (as defined in
18 U.S.C. 7) that is taken, possessed, transported, or sold in
violation of any State law or regulation, foreign law, or Indian
tribal law.
RESPONSIBLE FEDERAL AGENCIES:
USFWS -Responsible for the management/recovery, listing, and
law enforcement/protection of this species.
BLM -Responsible for the law enforcement/protection of this
species with applicable State and Federal laws on
public land under their control (43 CFR 4140). Also
responsible for management/recovery on Bureau of Land
Management lands.
All Federal agencies have responsibility to ensure that any
action authorized, funded, or carried out by that agency is not likely
to jeopardize the continued existence of the species or result in the
destruction or adverse modification of Critical Habitat (50 CFR 402),
and to utilize their authorities to carry out programs for the
conservation of the species.
STATE STATUSES AND LAWS:
STATE: Wyoming
STATUS: Recognized Endangered
Status - 1 (DRAFT) - Status
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
ADMINISTRATIVE AGENCY: Wyoming Game and Fish Dept.
STATE STATUTE: WY Stat. Annot. 23-1-101, 23-1-103, 23-3-301,
23-4-101, and 23-1-302; Regs. Chapt. XXXIII,
Issuance of Sci. Permits.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
None.
ECONOMIC STATUSES:
None.
82/12/30:47 FR 58454/58460 - Notice of review of proposed rule
83/01/27:48 FR 03794/03796 - Proposed rule
84/01/17:49 FR 01992/01994 - Final rule, Endangered
Status - 2 HABITAT ASSOCIATIONS
HABITAT - AQUATIC
TERRESTRIAL
INLAND AQUATIC
LAND USE -
Cropland and Pasture
Mixed Rangeland
Streams and Canals
Lakes
Nonforested Wetland
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Lacustrine, littoral EM2
2AB
Lacustrine, littoral AB1
Lacustrine, littoral AB
Lacustrine, littoral
Palustrine EM5
Palustrine EM1
Palustrine EM
Palustrine AB2
Palustrine AB1
Palustrine AB
Palustrine
COMMENTS ON HABITAT ASSOCIATIONS -
During the period from 1939 when it was first recognized in
the Laramie Basin, until at least the mid-sixties, the Wyoming toad
was relatively abundant but restricted to a relatively small range of
not more than about 600 square miles. The Laramie Basin is at an
elevation of between 7200 and 7500 feet above sea level; it is a
semi-arid, intermountain basin characterized by a predominant
vegetation of short-grasses and sagebrush. Since settlement and
development of agriculture, the central, lower portions of the basin
are irrigated using water diverted from the two major rivers, the Big
and Little Laramie Rivers (04).
The habitats utilized by the Wyoming toad were floodplains ponds,
small ponds and lakes produced by irrigation runoff, and the many
small seepage lakes in the basin. These last mentioned habitats are
shallow, seepage lakes whose basins were produced by wind erosion in a
prehistoric dry period when many blowout basins as well as sand dunes
were created in the Basin. They were surely very saline, and even dry
during periods of drought, in the years before irrigation was
initiated in the area. In the years when they were abundant in the
Basin, adult and immature toads were restricted to the sedge and grass
wet-meadows at the margins of these lakes, and to ponds on the
floodplain of the streams in the Basin. And adult toads were not
evident at all in late summer; they probably resorted to burrowing and
being active at night during late summer (04). The habitat is unique
in that the toads inhabit the bogs created by underground water
collecting into seepage lakes at the base of plateaus in "hollows"
created by the wind erosion. The habitat is very wet and be
classified as a wet grassland rangeland (09).
Any major change in land use patterns, and particularly in the
Habitat Associations - 1 manner of irrigation, such as sprinkle irrigation in place of
flooding, would affect the toad, probably adversely.
Hibernation (winter dormancy) behavior was never studied
carefully in this area. It was not believed to have been
water-related. In Minnesota, the parent species has been observed to
burrow into so-called Mima-mounds to a depth of 46 inches or more
(07). In the Laramie Basin, a good guess is that the toads burrowed
into softer soils such as areas where pocket gophers have tilled the
soils, possibly into the pocket gopher burrows themselves, possibly
into the extinct sand dunes that are quite common in areas where the
toad formerly occurred. In one way or another, the toad needed to
burrow to a depth below the frost line (08).
Mima-mound topography occurs in the Laramie Basin, but out on the
short-grass prairies these mounds are capped with cobblestones and are
of a texture making it difficult for a toad to burrow. On the
floodplains, in the areas where the toad was last observed, the
"Mimi-mounds" produce elevations two or three feet above the water
level when the meadows are being irrigated, and the caps of the mounds
are frquently heavily utilized by pocket gophers. It seems quite
likely that the Wyoming toad may have used such situations for
burrowing and winter dormancy, much the same as was observed in
Minnesota. Again, this is speculative; no one ever studied this
possibility scientifically. But herpetologists have speculated that
the existence of Mima-mound topography in the Laramie Basin may
explain the presence of the relict population of the "Canadian" or
Wyoming toad in Albany County, Wyoming (02).
Habitat Associations - 2 (DRAFT) - Food Habits
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
FOOD HABITS
TROPHIC LEVEL -
OMNIVORE
LIFESTAGE FOOD FOOD PART
General Algae
General Arthropods
Food Habits - 1 (DRAFT) - Environment Associations
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G
G
G Aquatic Features: Springs [flowing]
G Inland Wetlands: Bogs
G Terrestrial Features: Burrows
G
Environment Associations - 1 (DRAFT) - Life History
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
LIFE HISTORY
Detailed food habit studies for the Wyoming toad have never been
made. Adult toads are insectivorous and opportunistic in selection of
food. The literature on toad food habits always mentions ants and
beetles as preferred foods, but this may be simply because those hard-
to-digest items are the most conspicuous items in stomach contents.
Larvae of anurans feed primarily on periphytic algae. It is unlikely
that availability of food for either adults or larvae was in any way
limiting for this toad.
HOME RANGE/TERRITORY:
Home range and territory behavior of the Wyoming toad are
unknown.
PERIODICITY:
The adults and sub-adults are abundant and active during the
daylight hours in the sedges and grasses on the floodplain during June
and early July, but adults disappear during late July, probably
becoming largely nocturnal during the dry part of the summer and
remaining beneath the surface of the ground during the day; from
Baxter, 1950 (04).
MIGRATION PATTERNS:
This species is non-migratory (04).
COVER/SHELTER REQUIREMENTS:
The Wyoming toad needs vegetative cover such as sedges, grasses,
in a moist situation throughout the summer to protect against the high
evaporative power of the air in the relatively arid climate of the
Laramie Basin. It probably utilizes any soft earth such as pocket
gopher burrows, sand dunes, etc., to burrow to below the frost line
for winter dormancy (04,08).
REPRODUCTIVE SITE REQUIREMENTS:
The Wyoming toad requires warm (over 60 degrees F), shallow ponds
or lake margins, for reproduction; these ponds must remain filled
during the period from late May until at least mid-August for
completion of the tadpole stage (04,08).
REPRODUCTIVE CHARACTERISTICS:
In the period when this toad was common in the Larami Basin, the
adult toads emerged from winter dormancy in late May or early June,
after daily air temperatures approach 80 degrees F. Breeding
congresses developed in the warm, shallow floodplain ponds, and eggs
were laid there. Tadpoles normally completed their transformation to
adults by early August. Drying up of the floodplain ponds was a
noticeable cause of considerable mortality to the tadpoles (04).
Breckenridge and Testor determined that the parental subspecies
in Minnesota becomes sexually mature after about 23 months (07). This
was never determined for the subspecies found in Wyoming, but is
believed to be the same, at least for males; females may require a
year longer to become sexually mature (04,08).
Life History - 1 (DRAFT) - Life History
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
PARENTAL CARE:
None (04).
POPULATION BIOLOGY:
Never studied in detail.
SPECIES INTERRELATIONSHIPS:
None.
OTHER LIFE HISTORY DESCRIPTORS:
None known.
Life History - 2 (DRAFT) - Management Practices
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Maintaining/Controlling Water Flow
Beneficial Developing/maintaining/protecting wetlands
Beneficial Controlling water levels
Beneficial Controlling/Restricting Pesticide Use
Beneficial Maintaining Sperm/Seed Banks
Beneficial Stocking captive-reared wild-strain animals
Beneficial Transplanting Wild Eggs/Wild Seeds
Beneficial Disease Control Measures
Adverse Food Supply Reduction
Existing Food Supply Reduction
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Disease
Existing Disease
Adverse Predation
Existing Predation
Adverse Strip mining
Existing Strip mining
Adverse Water Level Fluctuation
Existing Water Level Fluctuation
Adverse Irrigating
Existing Irrigating
Adverse Applying herbicides
Existing Applying herbicides
Adverse Applying pesticides
Existing Applying pesticides
Adverse Grazing
Existing Grazing
Adverse
Existing
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
COMMENTS ON MANAGEMENT PRACTICES -
Reasons for the population decline are not entirely clear. The
1985 edition of Amphibians and Reptiles of Wyoming (02) stating,
"Widespread spraying of insecticides to control mosquitoes, changes in
agricultural practices, increases in predation, diseases, and climatic
changes have been suggested as casuses of the decline in numbers of
the Wyoming toad, but no certain cause has been identified."
The widespread decline of the Wyoming toad and other amphibian
species in the Laramie Basin coincided with the aerial application of
Baytex (Fenthion), an organophosphate pesticide, for mosquito control.
Although some laboratory tests have shown that Baytex is not toxic to
amphibians at levels prescribed for field applications, these results
do not entirely refute the connection between this pesticide toxicity
and the decline in the Wyoming toad population. Hall (10) reported
that ranid frog (Rana catesbeiana) tad poles significantly
Management Practices - 1 (DRAFT) - Management Practices
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
bioconcentrate Baytex, up to 62 times. These elevated concentrations
could have significant affects on larva toads when they undergo
metamorphosis into subadults. The biomagnification of Baytex by
algae is another major concern, since this is primarily found in
larval toads. Baytex spraying may also have significant effects on
subadults and adults food sources (insects), and could affect the
ability of the toad to overwinter.
Predation has been suggested as a possible cause of the
population crash. Toads in general do not suffer much predation
losses, since predators normally avoid them due to the bad taste
produced from their skin glands. During the time of the toads massive
decline, the California gull population has more than doubled. Gulls
are known to be a significant predator on other aquatic vertebrates
and it is conceivable that they maybe preying on the toads especially
tadpoles and larval toads undergoing metamorphosis. Raccoons and
white pelicans can not be ruled out either. Both species have
increased significantly in the Basin during the period of the toads
population decline. Predation of larvae and eggs by aquatic insects
also may be a concern. The overall concensus of the recovery working
group is that predation probably was not a significant factor in the
decline of the species, but is expected to be a major factor in
preventing the toads recovery.
Diseases are another possible cause of the population decline.
Amphibians are very susceptible to most fish diseases, especially red
leg. This disease has been suggested as a possible cause of frog
declines in upper mid-western United States (11).
An additional scenario may have been involved in the reduction in
numbers and possible extinction of the Wyoming toad. In the Laramie
Basin, the floodplains of the streams are utilized by agriculture, as
irrigated native hay meadows. In prehistoric times, the Wyoming toad
was probably restricted to these floodplains. In late May and early
June, during the spring runoff from the surrounding mountains, the hay
meadows are flooded and become an almost continuous shallow aquatic
system for many square miles. This period coincides exactly with the
breeding period of the Wyoming toad. In order to dry out the meadows
so that the hay can be harvested, the irrigation waters are turned
off abruptly sometime between the middle of July and the first of
August. Within a relatively short time, the hay is mowed. The
habitat is transformed from a very wet situation with a great deal of
vegetative cover to a very dry situation with almost no cover
whatsoever. The larvae may have not yet transformed at this time and
suffered high or complete mortalities, or the newly metamorphosed
immature toads may have been exposed to high rates of evaporation and
suffered high mortalities.
This is speculative. It is not known for sure what the specific
reason for the decline in numbers of the Wyoming toads.
UNAPPROVED PLAN:
No recovery plan has been prepared for the Wyoming toad as of yet.
The plan is scheduled to be completed in 1988.
The 1987 discovery of a healthy breeding population of this
Management Practices - 2 (DRAFT) - Management Practices
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
species has prompted the Service to establish a recovery working
group. This group will be responsible for developing the recovery
plan and assisting in its implementation. Mike Stone of the Wyoming
Game and Fish Department has the lead in writing the plan, which is
scheduled to be completed in 1988. Conservation measures being
discussed include:
1. Studies to determine exact reason for the decline, i.e.,
Baytex toxicity studies on surrogate species, predation,
diseases.
2. Egg transplants into suitable habitat. The concensus of
the working group is not to try adult transplants
(apparently adults have a strong homing ability); but to
transplant portions of egg masses and keep them in
protective cages until metamorphism has occurred.
3. Captive propagation was viewed as a last ditch effort by
the group. Zoos, however, may provide a good fall back
situation to keep a few individuals in case something
happened to the wild population.
4. Studies to determine important components of this species
wintering and breeding life histories.
5. Since the only known population is located solely on
private lands, it is extremely important that good
landowner relationship be maintained. Members of the
working group have contacted the primary landowner, and
he has been very supportive of our recovery efforts. The
Nature Conservancy has also been contacted, and they have
indicated their willingness to assist in the recovery
efforts, both monetarily and with landowner relationships.
6. Work with the local Mosquito Central Districts in an
effort to get a more biological sound mosquito control
program implemented. This program has been initiated.
Management Practices - 3 (DRAFT) - References
Species TOAD, WYOMING
Species Id ESIS206001
Date 14 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Porter, K.R. 1968. Evolutionary status of a relict population of
Bufo hemiophrys Cope. Evolution 22:583-594.
02 Baxter, G.T., and M.D. Stone. 1985. Amphibians and reptiles of
Wyoming. 2nd Ed. WY Game and Fish Dept., Laramie, WY.
03 Baxter, G.T. 1946. A study of the amphibians and reptiles of
Wyoming. Unpubl. M.S. thesis. Univ. of WY.
04 Baxter, G.T. 1952. The relation of temperature to the altitudinal
distribution of frogs and toads in southwestern Wyoming. Unpubl.
Ph.D. thesis. Univ. of Mich., Ann Arbor, Mich.
05 Baxter, G.T., and J.S. Meyer. 1982. The status and decline of the
Wyoming toad, Bufo hemiophrys baxteri. J. CO-WY Acad. of Sci.
14:33.
06 Baxter, G.T., M.R. Stromberg, and C.K. Doss, Jr. 1982. The status
of the Wyoming toad (Bufo hemiophrys baxteri). Environmental
Conserv. 9:348.
07 Breckenridge, W.J., and J.R. Tester. 1961. Growth, local
movements and hibernation of the Manitoba toad, Bufo hemiophrys.
Ecology 42(4):637-646.
08 Baxter, G.T. 1985. Pers. observ. Laramie, WY 82070.
09 Baxter, G.T. 1987. Pers. observ. Laramie, WY 82070.
10 Hall, R.J., Kolbe, E. 1980. Bioconcentration of organophosphorous
pesticides to hazardous levels by amphibians. J. Toxicol. Environ.
Health 6:853-860.
11 Anderson, A. 1988. Pers. knowledge. U.S. Fish and Wildl. Serv.,
Cheyenne, WY.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Baxter, G.T. 1964. A study of the amphibians and reptiles of
Wyoming. Unpubl. thesis, Univ. of WY., Laramie.
02 Baxter, G.T. and M.D. Stone. 1985. Amphibians and Reptiles of
Wyoming, 2nd Ed. Wyoming Game and Fish Dept., Laramie.
03 Baxter, G.T., and J.S. Meyer. 1982. The status and decline of the
Wyoming toad, Bufo hemiophrys baxteri. J. Colorado-Wyoming Acad.
of Sci. 14:33.
04 Lewis, D.L., et al. 1985. Possible extinction of the Wyoming
toad, Bufo hemiophrys baxteri. J. Herpetology 19(1):166-168.
05 Baxter, G.T. 1985. Pers. observ. Laramie, WY 82070.
06 Baxter, G.T. 1987. Pers. observ. Laramie, WY 82070.
07 Anderson, A. 1988. Pers. observ. U.S. Fish and Wildl. Serv.,
Cheyenne, WY.
References - 1