Woodhouse's Toad - Anaxyrus woodhousii
(see State Rank Reason below)
State Rank Reason (see State Rank above)
Species is apparently secure and not at risk of extirpation or facing significant threats in all or most of its range.
- Details on Status Ranking and Review
Woodhouse's Toad (Anaxyrus woodhousii) Conservation Status Review
Review Date = 05/03/2018
ScoreF - 20,000-200,000 km squared (about 8,000-80,000 square miles)
Comment194,937 square Kilometers from Natural Heritage Program range maps
ScoreD - Moderate Decline (decline of 25-50%)
CommentMany riparian habitats (prairie stream pool habitats) have been lost to land use changes over the last century. However species readily uses reservoirs and other man-made waterbodies if available. A net loss of habitat is likely since European arrival.
ScoreE - Stable. Population, range, area occupied, and/or number or condition of occurrences unchanged or remaining within ±10% fluctuation
CommentPopulations appear stable based on lentic surveys conducted over the last 15 years. Species was detected regularly during 2016 calling surveys.
ScoreH - Unthreatened. Threats if any, when considered in comparison with natural fluctuation and change, are minimal or very localized, not leading to significant loss or degradation of populations or area even over a few decades’ time. (Severity, scope, and/or immediacy of threat considered Insignificant.)
ScoreB - Moderately Vulnerable. Species exhibits moderate age of maturity, frequency of reproduction, and/or fecundity such that populations generally tend to recover from decreases in abundance over a period of several years (on the order of 5-20 years or 2-5 generations); or species has moderate dispersal capability such that extirpated populations generally become reestablished through natural recolonization (unaided by humans).
CommentThis species has high fecundity, a moderate age of maturity, and recruitment can be low.
ScoreC - Moderate. Generalist. Broad-scale or diverse (general) habitat(s) or other abiotic and/or biotic factors are used or required by the species but some key requirements are scarce in the generalized range of the species within the area of interest.
CommentDistributed widely across shrublands, grasslands, and badlands. Appears to use a range of lentic waterbody types for breeding
Raw Conservation Status Score
3.5 + 0 (geographic distribution) + 0 (environmental specificity) + 0 (short-term trend) + 1 (threats) = 4.5
Laid in long single or double strands containing up to or greater than 28,493 eggs (Smith 1934, Krupa 1995a). Each ovum is black above, gray below, and is loose within the outer jelly string (Smith 1934). Ovum diameters are 1.0 to 1.4 mm (0.04-0.06 in), but total egg diameters, including the outer jelly string are approximately 3.5 mm (0.14 in) (Smith 1934).
Body and tail musculature are black to dark brown with gold flecking dorsally and laterally and gray to white ventrally (Youngstrom and Smith 1936). The dorsal tail fin is dendritically pigmented, and the ventral tail fin is clear. Total length (TL) of 2.5 to 35 mm (0.1-1.4 in) (Youngstrom and Smith 1934, Hammerson 1999).
JUVENILES AND ADULTS
Except for small metamorphs, parallel cranial crests are found on the snout and behind the eyes in the shape of an “L”. Large parotid glands are present behind the eyes. The post-orbital crests typically touch the paratoid glands. If a lump is present on the snout, it does not extend back between the eyes. Very young transformed toads typically lack the dorsal line and often have reddish warts. Adults have dry skin with small warts and each hind foot has two dark digging ‘spades’ on their soles. A white stripe extends down the center of the back on adults and is surrounded by a green and creamy-yellowish mottling with greener toward the center line and creamier yellow toward the lateral surface. Usually completely white ventrally, but some black spotting may be present (Bragg 1940b, Maxell et al. 2009). Snout-vent length (SVL) of adults is 63.5-127 mm (2.5-5 in) (Smith 1934, Underhill 1960).
Calls are loud and can carry over a distance of 800 meters (~ 2,625 feet) (Bryce Maxell, personal communication). Calls are high-pitched nasal "waaaaaaaaah" that sounds lie a crying baby, lasting 2-10 seconds and repeated regularly or irregularly (Werner et al. 2004).
See the geographic range of Western Toad (Anaxyrus boreas
) for possible areas of overlap. Adults of the Western Toad lack cranial crests and are rarely found in areas far from forests. The Canadian toad (Anaxyrus hemiophrys
), if present, is likely to only occur in the extreme northeast corner of the state and has a lump between the eyes and frequently has the paratoid gland separate from the post-orbital crest, which is often broken.
Although overlap in habitat use exists the Great Plains Toad (Anaxyrus cognatus
) is more commonly associated with heavier soils in upland habitats (Timken and Dunlap 1965). Adults of the Great Plains Toad have a raised shield on the tip of the snout and the cranial crests between their eyes diverge to form a “V”. The Great Plains Toad has large, white-bordered, dark dorsal blotches. Metamorphs of the Great Plains Toad have large paired dorsal blotches.
Eggs and larvae of Western Toad, Great Plains Toad, and Canadian Toad are very similar and may not be differentiable by even thoroughly trained herpetologists. However, eggs and larvae of Great Plains Toad are more likely to be found in temporary waters (Bragg 1940a).
Western Hemisphere Range
The systematics of the Woodhouse’s Toad species complex have a long history, but most authors now seem to agree that allozyme and call differentiation studies support evidence for the existence of two subspecies. These subspecies range from southern Texas to northern Montana and North Dakota, across the desert southwest to northern Utah, and as isolated populations in Idaho, Washington and California (Stebbins 2003, Conant and Collins 1998, Gergus 1994 as cited in Sullivan et al. 1996b, Sullivan et al. 1996b). Across this range they have been reported at elevations up to 2,440 m (8,000 ft) (Hammerson 1999). Only the Woodhouse’s Toad (Bufo w. woodhousii) is present in Montana and they have been documented across the plains east of Livingston and Fort Benton and south of the Milk and Missouri Rivers.
Maximum elevation: 1,326 m (4,350 ft) in Rosebud County (FWP Prairie Fish Survey Crew, MTNHP 2007).
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
The Woodhouse’s Toad can be found in upland habitats with harder soils around areas with permanent waters. They are most common in floodplain and moist grassy areas around water that have loose sandy soils or muddy bottoms (Bragg 1940b, Timken and Dunlap 1965, Black 1970d, Baxter and Stone 1980). Many records from eastern Montana are in non-forested habitats, but some occur in transition vegetation, including Ponderosa Pine (Pinus ponderosa
) and savannah forests (Black 1970d). Adults shelter under surface debris, in rodent burrows, or in shallow, self-excavated burrows when terrestrial conditions are not favorable (Bragg 1940b, Smith and Bragg 1949, Clarke 1974a, Labanick and Schleuter 1977, Flowers and Graves 1995, Swanson et al. 1996). Egg strings are wrapped around vegetation in shallow areas of lakes, reservoirs, river backwaters, floodplain pools, and irrigation ditches (Black 1970d, Maxell et al. 2009). Juveniles may not normally move greater than 200 m (656 ft) from natal sites, but individuals are known to disperse up to 2 km (1.2 mi) from natal breeding sites (Breden 1988).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: mtnhp.org/requests
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
- Commonly Associated with these Ecological Systems
Forest and Woodland Systems
Human Land Use
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Sparse and Barren Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Human Land Use
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Tadpoles feed on algae and detritus, while adults feed on a variety of invertebrates. Adults have been known to collect under streetlights and feed on insects. Stomach contents can account for up to 16% of body weight. (Youngstrom and Smith 1936, Bragg 1940b, Breden 1988, Flowers and Graves 1995).
The Woodhouse’s Toad is believed to be one of the most versatile and wide-ranging toads regarding distribution (Black 1970d). Temperatures of 20 to 30 °C (68-86 °F) are most favorable for nocturnal activity. During the day, individuals remain under cover of rocks or burrowed in soil or damp cover near water (Hammerson 1982). Adults are known to live up to 19 years of age (Engeman and Engeman 1996).
Breeding and egg laying are spread out over spring and early summer (April to July) in streams, rivers, irrigation ditches, in shallow water without strong current (Black 1970d). Breeding takes place during or after spring or summer rains when temperatures are at least 10 °C (50 °F). Choruses may form in drier weather and larger breeding choruses may only form at or above 16 °C (60.8 °F) (Breden 1988). Tadpoles hatch within three days and usually transform in 5-8 weeks (Youngstrom and Smith 1936; Bragg 1940b; Breden 1988).
The following was taken from the Status and Conservation section for the Woodhouse’s Toad account in Maxell et al. 2009
Woodhouse’s Toads are widely distributed and common in river valleys, smaller water courses with pools, and artificial permanent water bodies on the prairies east of the Rocky Mountains and island mountain ranges. However, their status north of the Missouri River is largely uncertain. Risk factors relevant to the viability of populations of this species are likely to include grazing, nonindigenous species and their management, road and trail development and on- and off-road vehicle use, development of water impoundments, and habitat fragmentation, all as described above. Individual studies that specifically identify risk factors or other issues relevant to the conservation of Woodhouse’s Toad include the following. (1) Taylor et al. (1999) found that Woodhouse’s Toad adults exposed to 0.0011 mg of Malathion per gram of toad (a level similar to levels commonly applied) suffered 40% mortality rates. Furthermore, when exposed to Malathion and subsequently injected with the bacteria Aeromonas hydrophila
the mortality rate increased. Thus, the application of the pesticide clearly reduced the immune function of Woodhouse’s Toads. Similarly, Ferguson and Gilbert (1967) found juveniles of the Woodhouse’s Toad to be very sensitive to the insecticides aldrin and dieldrin, but found that animals collected from sites that were contaminated with these chemicals exhibited up to a 200-fold increase in resistance over animals collected from pristine sites. Finally, Sanders (1970a) studied the sensitivities of larval Woodhouse’s Toads to 18 pesticides and herbicides and found most of them to result in high rates of mortality when exposed for 48 or 96 hours. However, a number of pesticides and herbicides had significant impacts on survival after a 24-hour exposure. The extent of the application of these herbicides and pesticides in Montana is not known, but it is likely that both herbicides and pesticides represent lethal and sublethal threats to Woodhouse’s Toad populations. (2) Bragg (1940b) and Hammerson (1999) both report that thousands of Woodhouse’s Toads are killed by or on roads near breeding sites. Furthermore, Barrass (1986) found that noise associated with highway traffic alters the reproductive behavior of Woodhouse’s Toads. Animals were less likely to move toward a breeding chorus and were more likely to call closer to one another in an established chorus in the presence of highway noise. (3) Freda and Dunson (1986) found embryos were intolerant of low pH (pH < 4.0) in the lab and were absent from all ponds with pH lower than 4.1. Furthermore, they found that larvae grew significantly slower in waters with pH less than 6.0. Pierce and Montgomery (1989) exposed larvae to short term acidic conditions (three days in water at pH = 4.0) and found that while short term exposures temporarily reduced the growth rates of individuals, long-term effects on growth, size at metamorphosis, and time to metamorphosis were not evident. (4) Many toad larvae are unpalatable to fish and may, therefore, have some resistance to the impacts of fish introductions. Kruse and Stone (1984) found that largemouth bass (Micropterus salmoides
) learned to avoid feeding on Woodhouse’s Toad tadpoles because of their unpalatability and aggregative behavior. However, bass did still prey on some tadpoles and the indirect effects of fish may still have considerable consequences. For example, Lawler (1989) found Woodhouse’s Toad tadpoles to greatly reduce activity levels in the presence of a fish predator. This decreases their foraging efficiency and increases their larval period, which exposes them to other predators for a longer period of time. (5) Bragg (1940b) reports that they are preyed upon by American Bullfrogs (Lithobates catesbeianus
). (6) Bragg (1940b) notes that young toads are commonly used as fish bait in Oklahoma.
- Literature Cited AboveLegend: View Online Publication
- Barrass, A.N. 1986. The effects of highway traffic noise on the phonotactic and associated reproductive behavior of selected anurans. Dissertation Abstracts International B Sciences and Engineering 46(8): 2609.
- Baxter, G.T. and M.D. Stone. 1980. Amphibians and reptiles of Wyoming. Wyoming Game & Fish Department, Cheyenne. 137 pp.
- Black, J.H. 1970d. Some aspects of the distribution, natural history and zoogeography of the toad genus Bufo in Montana. M.S. thesis. University of Montana, Missoula, MT. 70 p.
- Bragg, A. N. 1940a. Observations on the ecology and natural history of Anura. I. Habits, habitat and breeding of Bufo cognatus Say. American Naturalist 74: 322-349, 424-438.
- Bragg, A.N. 1940b. Observations on the ecology and natural history of Anura II. Habits, habitat, and breeding of Bufo woodhousei woodhousei (Girard) in Oklahoma. American Midland Naturalist 24: 306-321.
- Breden, F. 1988. Natural history and ecology of Fowler's toad (Bufo woodhousei fowleri) (Amphibia: Bufonidae), in the Indiana Dunes National Lakeshore (USA). Fieldiana Zoology No. 49: 1-16.
- Clarke, R.D. 1974a. Activity and movement patterns in a population of Fowler's toad, Bufo woodhousei fowleri. American Midland Naturalist 91: 140-147.
- Conant, R. and J.T. Collins 1998. A field guide to reptiles and amphibians of eastern and central North America. Third edition, expanded. Houghton Mifflin Company. Boston, MA. 616 p.
- Engeman, R.M. and E.M. Engeman. 1996. Longevity of Woodhouse's toad in Colorada. Northwestern Naturalist 77: 23.
- Ferguson, D.E. and C.C. Gilbert. 1967. Tolerances of three species of anuran amphibians to five chlorinated hydrocarbon insecticides. Journal of Mississippi Academy of Sciences 13: 135-138.
- Flowers, M.A. and B.M. Graves. 1995. Prey selectivity and size-specific diet changes in Bufo cognatus and Bufo woudhousii during early postmetamorphic ontogeny. Journal of Herpetology 29(4): 608-612.
- Freda, J. and W.A. Dunson. 1986. Effects of low pH and other chemical variables on the local distribution of amphibians. Copeia 1986(2): 454-466.
- Gergus, E.W.A. 1994. Systematics and biogeography of Bufo microscaphus (Anura: Bufonidae), with a preliminary report on americanus group phylogeny. M.S. Thesis, San Diego State University.
- Hammerson, G.A. 1982. Bullfrog eliminating leopard frogs in Colorado? Herpetological Review 13: 115-116.
- Hammerson, G.A. 1999. Amphibians and reptiles in Colorado. University Press of Colorado & Colorado Division of Wildlife. Denver, CO. 484 p.
- Krupa, J.J. 1995a. Bufo woodhousi (Woodhouse's toad). Fecundity. Herpetological Review 26: 142-144.
- Kruse, K.C., and B.M. Stone. 1984. Largemouth bass (Micropterus salmoides) learn to avoid feeding on toad (Bufo) tadpoles. Animal Behaviour 32(4):1035-1039.
- Labanick, G.M. and R.A. Schlueter. 1977. Diets of sympatric Acris crepitans and juvenile Bufo woodhousei fowleri in western Indiana. Proceedings of the Indiana Academy of Science 86: 460.
- Lawler, S.P. 1989. Behavioral responses to predators and predation risk in four species of larval anurans. Animal Behaviour 38: 1039-1047.
- Pierce, B.A. and J. Montgomery. 1989. Effects of short-term acidification on growth rates of tadpoles. Journal of Herpetology 23(2): 97-102.
- Sanders, H.O. 1970a. Pesticide toxicities to tadpoles of thet western chorus frog (Pseudacris triseriata) and Fowler's toad (Bufo woodhousei fowleri). Copeia 1970: 246-251.
- Smith, C.C. and A.N. Bragg. 1949. Observations on the ecology and natural history of Anura, VII. Food and feeding habits of the common species of toads in Oklahoma. Ecology 30(3): 333-349.
- Smith, H.M. 1934. The amphibians of Kansas. American Midland Naturalist 15(4): 377-528.
- Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. 3rd Edition. Houghton Mifflin Company, Boston and New York. 533 p.
- Sullivan, B.K., K.B. Malmos and M.F. Given. 1996b. Systematics of the Bufo woodhousii complex (Anura: Bufonidae): advertisement call variation. Copeia 1996: 274-280.
- Swanson, D.L., B.M. Graves and K.L. Koster. 1996. Freezing tolerance/intolerance and cryoprotectant synthesis in terrestrially overwintering anurans in the Great Plains, USA. Journal of Comparative Physiology B Biochemistry, Systematics and Environment
- Taylor, S.K., E.S. Williams, and K.W. Mills. 1999. Effects of malathion on disease susceptibility in Woodhouse's toads. Journal of Wildlife Diseases 34(3): 536-541.
- Timken, R.L. and D.G. Dunlap. 1965. Ecological distribution of the two species of Bufo in southeastern South Dakota. Proceedings of the South Dakota Academy of Sciences 44: 113-117.
- Underhill, J.C. 1960. Breeding and growth in Woodhouse's toad. Herpetologica 16: 237-242.
- Youngstrom, K.H. and H.M. Smith. 1936. Description of the larvae of Pseudacris triseriata and Bufo w. woodhousii. American Midland Naturalist 17: 629-633.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- [DCC] Decker Coal Company. 1998. 1997 Consolidated annual progress report. Decker Coal Company West, North and East Pits. Decker, MT.
- [OEA] Olson Elliot and Associates Research. 1985. 1983-1984 Wildlife monitoring report for the CX Ranch project. Olson Elliot and Associates Research. Helena, MT.
- [PRESI] Powder River Eagle Studies Incorporated. 1998a. Big Sky Mine 1997 wildlife monitoring studies. Powder River Eagle Studies Incorporated. Gillete, WY.
- [PRESI] Powder River Eagle Studies Incorporated. 1998b. Spring Creek Mine 1997 wildlife monitoring studies. Powder River Eagle Studies Incorporated. Gillete, WY.
- [WESCO] Western Ecological Services Company. 1983a. Wildlife inventory of the Knowlton known recoverable coal resource area, Montana. Western Ecological Services Company, Novato, CA. 107 p.
- [WESCO] Western Ecological Services Company. 1983b. Wildlife inventory of the Southwest Circle known recoverable coal resource area, Montana. Western Ecological Services Company, Novato, CA. 131 p.
- [WESTECH] Western Technology and Engineering Incorporated. 1998. Wildlife Monitoring Absaloka Mine Area 1997. Western Technology and Engineering, Inc., Helena, Mt.
- Altig, R. and W. McDearman. 1975. Percent assimilation and clearance times of five anuran tadpoles. Herpetologica 31(1): 67-69.
- Anderson, B.D., M.E. Feder and R.J. Full. 1991. Consequences of a gait change during locomotion in toads (Bufo woodhousei fowleri). Journal of Experimental Biology 158: 133-148.
- Atkinson, E.C. and M.L. Atkinson. 2004. Amphibian and reptile survey of the Ashland and Sioux of the Custer National Forest with special emphasis on the Three-Mile Stewardship Area:2002. Marmot's Edge Conservation. 22 p.
- Bacon, L.M. 1996. Nesting ecology of the Interior Least Tern on the Yellowstone River, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 69 p.
- Barrass, A.N. and L.F. Cohn 1984. Variation of the spacing of calling male Bufo woodhousei and Hyla cinerea near highway noise. American Zoologist 24(3): 15A.
- Baxter, G.T. and M.D. Stone. 1985. Amphibians and reptiles of Wyoming. Second edition. Wyoming Game and Fish Department. Cheyenne, WY. 137 p.
- Bergeron, D. 1978. Terrestrial Wildlife Survey Coal creek Mine Area, Montana. Unpublished report for Coal Creek Mining Co., Ashland, Montana.
- Black, J.H. 1967a. Toads of Montana. Montana Wildlife 1967(Spring): 22-28.
- Black, J.H. 1971. The toad genus Bufo in Montana. Northwest Science 45: 156-162.
- Black, J.H., and A.N. Bragg. 1968. New additions to the herpetofauna of Montana. Herpetologica 24: 247.
- Blair, W.F. 1956a. Comparative survival of hybrid toads (B. woodhousei X B. valliceps) in nature. Copeia 1956: 259-260.
- Blem, C.R. 1992. Lipid reserves and body composition in postreproductive anurans. Comparative Biochemistry and Physiology A Comparative Physiology 103(4): 653-656.
- Boone, M.D. 2005. Juvenile frogs compensate for small metamorph size with terrestrial growth: Overcoming the effects of larval density and insecticide exposure. Journal of Herpetology 39(3):416-423.
- Boone, M.D. and R.D. Semlitsch. 2002. Interactions of an insecticide with competition and pond drying in amphibian communities. Ecological Applications 12(1):307-318.
- Bragg, A.N. 1939a. Possible hybridization of Bufo cognatus and B. w. woodhousii. Copeia 1939(3): 173.
- Bragg, A.N., and O. Sanders. 1951. A new subspecies of the Bufo woodhousii group of toads (Salientia: Bufonidae). Wasmann Journal of Biology 9: 363-378.
- Bramblett, R.G., and A.V. Zale. 2002. Montana Prairie Riparian Native Species Report. Montana Cooperative Fishery Research Unit, Montana State University - Bozeman.
- Breden, F. 1987. The effect of post-metamorphic dispersal on the population genetic structure of Fowler's Toad (Bufo woodhousei fowleri). Copeia 1987(2): 386-395.
- Breden, F., A. Lum, and R. Wassersug. 1982. Body size and orientation in aggregates of toad tadpoles Bufo woodhousei. Copeia 1982(3): 672-680.
- Breden, F.J. 1982. Population structure and ecology of the Fowler’s toad, Bufo woodhousei fowleri, in the Indiana Dunes National Lakeshore. Ph.D. Dissertation, University of Chicago.
- Brown, L.E. 1970. Interspecies interaction as possible causes of racial size differences in the toads, Bufo americanus and Bufo woodhousei. Texas Journal of Science 21(3): 261-267.
- Brown, L.E. 1971. Natural hybridization and reproductive ecology of two toad species in a disturbed environment. American Midland Naturalist. 86(1): 78-85.
- Brown, L.E. and J.A. Brownell. 1971. Relative survival of two toad species and their natural hybrids in a disturbed environment. American Midland Naturalist. 86(1): 235-238.
- Brunson, R.B. 1955. Check list of the amphibians and reptiles of Montana. Proceedings of the Montana Academy of Sciences 15: 27-29.
- Burton, S.R., D.A. Patla, and C.R. Peterson. 2002. Amphibians of Red Rock Lakes National Wildlife Refuge: occurrence, distribution, relative abundance, and habitat associations. Herpetology Laboratory, Department of Biological Sciences, Idaho State University, Pocatello, ID. 66 p.
- Bush, F.M. and E.F. Menhinick. 1962. The food of Bufo woodhousei fowleri. Herpetologica 18: 110-114.
- Butts, T.W. 1997. Mountain Inc. wildlife monitoring Bull Mountains Mine No. 1, 1996. Western Technology and Engineering. Helena, MT.
- Calisi, R.M. 2005. Variation in Bidder's organ volume is attributable to reproductive status in Bufo woodhousii. Journal of Herpetology 39(4):656-659.
- Chiszar, D. and H.M. Smith. 1992. Bufo woodhousii woodhousii (Woodhouse’s toad). Herpetological Review 23(4): 122.
- Chiszar, D. and H.M. Smith. 1993. Bufo woodhousii woodhousii (Woodhouse’s toad). Herpetological Review 24(4): 153.
- Clarke, R. D. 1974a. Activity and Movement Patterns in a Population of Fowler'S Toad, Bufo Woodhousii Fowleri. American Midland Naturalist 92:257-274.
- Clarke, R.D. 1972. The effect of toe clipping on survival in Fowler's toad (Bufo woodhousei fowleri). Copeia 1972: 182-185.
- Clarke, R.D. 1974b. Food habits of toads, genus Bufo (Amphibia:Bufonidae). American Midland Naturalist 91(1): 140-147.
- Clarke, R.D. 1974d. The autoecology of Fowler’s toad Bufo woodhousei fowleri Hinckley. Ph.D. Dissertation, Yale University. 182 p.
- Clarke, R.D. 1975. Post-metamorphic growth rates in a natural population of Fowler's toads (Bufo woodhouseii fowleri). Canadian Journal of Zoology 52: 1489-1498.
- Clarke, R.D. 1977. Postmetamorphic survivorship of Fowler's toad (Bufo woodhousei fowleri). Copeia 1977(3): 594-597.
- Claussen, D.L. 1974. Urinary bladder water reserves in the terrestrial toad, Bufo fowleri, and the aquatic frog, Rana clamitans. Herpetologica 30(4): 360-367.
- Claussen, D.L. and J.R. Layne, Jr. 1983. Growth and survival of juvenile toads, Bufo woodhousei, maintained on four different diets. Journal of Herpetology 17(2): 107-112.
- Confluence Consulting Inc. 2010. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Confluence Consulting Inc. 2011. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Cope, E. D. 1879. A contribution to the zoology of Montana. American Naturalist 13(7): 432-441.
- Cope, E.D. 1889. The Batrachia of North America. Bulletin of the U.S. National Museum 34: 1-525, figs. 1-119, pls. 1-86.
- Corn, P.S., E. Muths, and W.M. Iko. 2000. A comparison in Colorado of three methods to monitor breeding amphibians. Northwestern Naturalist 81:22-30.
- Coues, E. and H. Yarrow. 1878. Notes on the herpetology of Dakota and Montana. Bulletin of the U.S. Geological Geographic Survey of the Territories 4: 259-291.
- Crother, B.I. (ed.) 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico. SSAR Herpetological Circular No. 37:1-84.
- Day, D. 1989. Montco Terrestrial Wildlife Monitoring Report. Unpublished report for Montco, Billings, Montana.
- Day, D., P.J. Farmer, and C.E. Farmer. 1989. Montco terrestrial wildlife monitoring report December, 1987 - July, 1989. Montco, Billings, MT, and Western Technology and Engineering, Inc. Helena, MT.
- Dodd, C.K., Jr. 1977. Immobility in juvenile Bufo woodhousei fowleri. Journal of the Mississippi Academy of Science 22: 90-94.
- Dood, A.R. 1980. Terry Badlands nongame survey and inventory final report. Montana Department of Fish, Wildlife, and Parks and Bureau of Land Management, Helena, MT. 70 pp.
- Edwards, J.R., J.L. Jenkins, and D.L. Swanson. 2004. Seasonal effects of dehydration on glucose mobilization in freeze-tolerant chorus frogs (Pseudaris triseriata) and free-tolerant toads (Bufo woodhousii and B. cognatus). Journal of Experimental Zoolo
- Engeman, R.M. and M.A. Engeman. 2003. Longevity of a Woodhouse's Toad. Northwestern Naturalist 84:45.
- Fairchild, L. 1981. Mate selection and behavioral thermoregulation in Fowler's toads. Science 212: 950-951.
- Farmer, P. 1980. Terrestrial wildlife monitoring study, Pearl area, Montana June, 1978 - May, 1980. Western Technology and Engineering, Inc. Helena, MT.
- Farmer, P. J. 1980. Terrestrial Wildlife Monitoring Study, Pearl Area, Montana, June, 1978 - May, 1980. Tech. Rep. by WESTECH for Shell Oil Co.
- Fjell, Alan K., 1986, Peabody Coal Company Big Sky Mine, Rosebud County, MT. Wildlife monitoring report: 1985 field season. March 1986.
- Flath, D.L. 2002. Reptile and amphibian surveys in the Madison-Missouri River Corridor, Montana. Annual Progress Report. 14pp.
- Flowers, M.A. and B.M. Graves. 1994. Feeding ecology of juvenile great plains toad (Bufo cognatus) and woodhouse's toad (Bufo woudhousii). North Dakota Academy of Science Proceedings. 48: 22
- Force, E.R. 1925. Notes on reptiles and amphibians of Okmulgee County, Oklahoma. Copeia 1925(141): 25-27.
- Gates, M.T. 2005. Amphibian and reptile baseline survey: CX field study area Bighorn County, Montana. Report to Billings and Miles City Field Offices of Bureau of Land Management. Maxim Technologies, Billings, MT. 28pp + Appendices.
- Girard, C.F. 1854. Proceedings of the Academy of National Sciences, Philadelphia. Volume 7, p. 86.
- Given, M.F. 1993. Vocal interactions in Bufo woodhousii fowleri. Journal of Herpetology 27(4): 447-452.
- Given, M.F. 1996. Intensity modulation of advertisement calls in Bufo woodhousii fowleri. Copeia 1996(4): 970-977.
- Given, M.F. 2002. Interrelationships among calling effort, growth rate, and chorus tenure in Bufo fowleri. Copeia 4:979-987.
- Goldberg, S.R., C.R. Bursey, K.B. Malmos, B.K. Sullivan and H. Cheam. 1996. Helminths of the southwestern toad, Bufo microscaphus, woodhouse's toad, Bufo woodhousii (Bufonidae), and their hybrids from central Arizona. Great Basin Naturalist 56(4): 369-
- Green, D.M. 1989. Fowler's toad (Bufo woodhousii fowleri) in Canada: biology and population status. Canadian Field Naturalist 103(4): 486-496.
- Green, D.M. 1992. Fowler's toads (Bufo woodhouseii fowleri) at Long Point, Ontario: changing abundance and implications for conservation. In: C.A. Bishop and K.E. Pettit (eds.), Declines in Canadian amphibian populations : designing a national monitor
- Green, D.M. 1992. Fowler's toads (Bufo woodhouseii fowleri) at Long Point, Ontario: changing abundance and implications for conservation. In: C.A. Bishop and K.E. Pettit (eds.), Declines in Canadian amphibian populations : designing a national monitoring strategy, pp. 37-45. Canadian Wildlife Service Occ. Publ 76, Ottawa.
- Grogan, W.L., Jr., and P.G. Bystrak. 1973. Early breeding activity of Rana sphenocephala and Bufo woodhousei fowleri in Maryland. Bulletin of the Maryland Herpetological Society 9: 106.
- Grubb, J.C. 1973. Olfactory orientation in Bufo woodhousei fowleri, Pseudacris clarki and Pseudacris streckeri. Animal Behavior 21(4): 726-732.
- Hadfield, S. 1966. Observations on body temperature and activity in the toad Bufo woodhousei fowleri. Copeia 1966: 581-582.
- Hanauska-Brown, L., B.A. Maxell, A. Petersen, and S. Story. 2014. Diversity Monitoring in Montana 2008-2010 Final Report. Montana Fish, Wildlife & Parks. Helena, MT. 78 pp.
- Hardin, E.L. and J Janovy, Jr. 1988. Population dynamics of Distoichometra bufonis (Cestoda: Nematotaeniidae) in Bufo woodhousei. Journal of Parasitology 74(3): 360-365.
- Hayden, F.V. 1862. On the geology and natural history of the upper Missouri. Transactions of the American Philosophical Society New Series 12(1): 1-218
- Hendricks, P. 1999a. Amphibian and reptile survey of the Bureau of Land Management Miles City District, Montana. Montana Natural Heritage Program, Helena, MT. 80 p.
- Hendricks, P. and J.D. Reichel. 1996b. Preliminary amphibian and reptile survey of the Ashland District, Custer National Forest: 1995. Montana Natural Heritage Program, Helena, MT. 79 p.
- Hendricks, P. and J.D. Reichel. 1998. Amphibian and reptile survey on Montana refuges: 1996. Montana Natural Heritage Program, Helena, MT. 19 p.
- Hendricks, P., S. Lenard, D.M. Stagliano, and B.A. Maxell. 2013. Baseline nongame wildlife surveys on the Fort Peck Indian Reservation. Report to the Assiniboine and Sioux Tribes of the Fort Peck Indian Reservation. Montana Natural Heritage Program, Helena, MT. 83 p.
- Hossack, B. and P.S. Corn. 2001. Amphibian survey of Medicine Lake National Wildlife Refuge Complex: 2001. USGS Northern Rocky Mountain Science Center, Aldo Leopold Wilderness Research Institute, Missoula, MT. 13 p.
- Hranitz, J.M., W.J. Diehl and T.S. Klinger. 1992. Genetic diversity in insular, peninsular and mainland populations of Bufo woodhousei fowleri. Journal of the Mississippi Academy of Science 37(1):65.
- Humphris, Michael., 1993, Wildlife Monitoring Report. Spring Creek Coal Company 1993 Mining Annual Report. Appendix I. April 11, 1993.
- Humphris, Michael., 1994, Wildlife Monitoring Report. Spring Creek Coal Company 1994 Mining Annual Report. Appendix I. April 1994.
- Jilek, R. and R. Wolff. 1978. Occurrence of Spintectus gracilis Ward and Magath 1916 (Nematoda: Spiruroidea) in the toad Bufo woodhousei fowleri in Illinois. Journal of Parasitology 64(4): 619.
- John-Alder, H.B., and P.J. Morin. 1990. Effects of larval density on jumping ability and stamina in newly metamorphosed Bufo woodhousii fowleri. Copeia 1990(3): 856-860.
- Johnson, J.D. and T.J. LaDuc. 1994. Bufo woodhousii woodhousii (Woodhouse’s toad) Herpetological Review 25(4):159.
- Johnson, V.O. 1939. A supplementary note on the larvae of Bufo woodhousii woodhousii. Herpetologica 1: 162-164.
- Jones, J.M. 1973. Effects of thirty years hyridization on the toads Bufo americanus and Bufo woodhousei fowleri at Bloomington, Indiana. Evolution 27: 435-448.
- Jones, Lawrence L. C., W. P. Leonard and D. H. Olson, eds. 2005. Amphibians of the Pacific Northwest. Seattle Audubon Society: Seattle, WA, 227 pp.
- Joslin, Gayle, and Heidi B. Youmans. 1999. Effects of recreation on Rocky Mountain wildlife: a review for Montana. [Montana]: Montana Chapter of the Wildlife Society.
- Kellner, A. and D.M. Green. 1995. Age structure and age at maturity in Fowler's toads (Bufo woodhousii fowleri) at their northern range limit. Journal of Herpetology 29(3): 485-489.
- Klimstra, W.D. and C.W. Myers. 1965. Foods of the toad, Bufo woodehousi fowleri Hinckley. Transactions of the Illinois State Academy of Science 58: 757-764.
- Labanick, G.M. and R.A. Schlueter. 1976. Growth rates of recently transformed Bufo woodhousei fowleri. Copeia 1976(4): 824-826.
- Landreth, H.F. and D.E. Ferguson. 1968. The sun compass of Fowler's toad (Bufo woodhousei fowleri). Behaviour 30: 27-43.
- Laurin, G. and D.M. Green. 1990. Spring emergence and male chorus behavior in Fowler's toads, Bufo woodhousei fowleri, at Long Point, Ontario (Canada). Canadian Field Naturalist 104(3): 429-434.
- Lawler, S.P. and P.J. Morin. 1993. Temporal overlap, competition, and priority effects in larval anurans. Ecology 74(1): 174-182.
- Leary, C.J. 1996. Anura: Bufo woodhousii and B. americanus (woodhouse's toad and American toad). Vocalization. Herpetological Review 27(3): 139.
- Leary, C.J., T.S. Jessop, A.M. Garcia, and R. Knapp. 2004. Steroid hormone profiles and relative body condition of calling and satelittle toads: implications for proximate regulation behavior in anurans. Behavioral Ecology 15(2):313-320.
- Lillywhite, H.B. 1978. Anuran thermoregulation: new insights from a field study of Bufo woodhousei. American Zoologist 18(3): 573.
- Loftus Hills, J.J. 1975. The evidence for reproductive character displacement between the toads Bufo americanus and Bufo woodhousei fowleri. Evolution 29: 368-369.
- Lomolino, M.V. and G.A. Smith. 2004. Terrestrial vertebrate communities at black-tailed prairie dog (Cynomys ludovicianus) towns. Biological Conservation 115(1):89-100.
- Londos, P.L. and R.J. Brooks. 1988. Effect of temperature acclimation on locomotory performance curves in the toad, Bufo woodhousei woodhousei. Copeia 1988(1): 26-32.
- Londos, P.L. and R.J. Brooks. 1990. Time course of temperature acclimation of locomotory performance in the toad, Bufo woodhousei woodhousei. Copeia 1990(3): 827-835.
- Long, D.R. 1987a. A comparison of energy substrates and reproductive patterns of two anurans, Acris crepitans and Bufo woodhousei. Comparative Biochemistry and Physiology A Comparative Physiology 87(1): 81-92.
- Martin, P.R. 1980a. Terrestrial wildlife habitat inventory in southeastern Montana. Montana Department of Fish, Wildlife and Parks and Bureau of Land Management, Helena MT. 114 p.
- Martin, P.R. 1980b. Terrestrial wildlife inventory in selected coal areas of Montana. Montana Department of Fish, Wildlife and Parks and Bureau of Land Management, Helena, MT. 84 p.
- Martin, P.R., K. Dubois and H.B. Youmans. 1981. Terrestrial wildlife inventory in selected coal areas, Powder River resources area final report. Montana Department of Fish, Wildlife and Parks and Bureau of Land Management, Helena, MT. No. YA-553-CTO- 24. 288 p.
- Masta, S. E., N.M. Laurent, and E.J. Routman. 2003. Population genetic structure of the toad Bufo woodhousii: an empirical assessment of the effects of haplotype extinction on nested cladistic analysis. Molecular Ecology 12(6): 1541-1554.
- Matthews, W.L. 1979. Wibaux-Beach wildlife baseline study - nongame species. Bureau of Land Management, Miles City, MT. 93 p.
- Matthews, W.L. 1980b. Wildlife of Prairie County Terry study area. Bureau of Land Management, Miles City, MT. 52 p.
- Matthews, W.L. 1981. Broadus-Pumpkin Creek baseline inventory - wildlife. Bureau of Land Management, Miles City, MT. 83 p.
- Matthews, W.L. 1982. Bloomfield-North Fork Baseline Inventories - Wildlife. Unpublished report to the Bureau of Land Management, Miles City, Montana. 61 pp.
- Maxell, B. A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to USFS Region 1, Order Number 43-0343-0-0224. University of Montana, Wildlife Biology Program. Missoula, MT. 161 p.
- Maxell, B.A. 2016. Northern Goshawk surveys on the Beartooth, Ashland, and Sioux Districts of the Custer-Gallatin National Forest: 2012-2014. Montana Natural Heritage Program. Helena, MT. 114pp.
- Maxell, B.A., J.K. Werner, P. Hendricks, and D.L. Flath. 2003. Herpetology in Montana: a history, status summary, checklists, dichotomous keys, accounts for native, potentially native, and exotic species, and indexed bibliography. Society for Northwestern Vertebrate Biology, Northwest Fauna Number 5. Olympia, WA. 135 p.
- Maxim Technologies, Inc., 2002, Western Energy Company Rosebud Mine, Colstrip, Montana: 2002 Annual Wildlife Monitoring Report; December 1, 2001 - November 30, 2002. Febr. 24, 2002.
- McEneaney, T. and J. Jensen. 1974. The reptiles and amphibians of the Charles M. Russell National Wildlife Range - 1974. Charles M. Russell National Wildlife Refuge. Lewistown, MT. 3 p.
- Mecham, W.R. 1962. Factors affecting secondary intergradation between two allopatric populations in the Bufo woodhousei complex. American Midland Naturalist 67: 282-304.
- Mitchell, S.L. 1990. The mating system genetically affects offspring performance in Woodhouse's toad (Bufo woodhousei). Evolution 44(3): 502-519.
- Moll, E.O. 2004. Patronyms of the pioneer west. IV. Bufo woodhousii, Girard 1854--Woodhouse's toad. Sonoran Herpetologist 17(1):2-5.
- Morin, P.J., S.P. Lawler, and E.A. Johnson. 1988. Competition between aquatic insects and vertebrates: Interaction strength and higher order interactions. Ecology 69(5): 1401-1409.
- Mulcahy, D.G., M.R. Cummer, J.R. Mendelson III, B.L. Williams, and P.C. Ustach. 2002. Status and distribution of two species of Bufo in the Northeastern Bonneville Basin of Idaho and Utah. Herpetological Review 33(4):287-289.
- Nussbaum, R.A., E.D. Brodie, Jr. and R.M. Storm. 1983. Amphibians and reptiles of the Pacific Northwest. University of Idaho Press. Moscow, ID. 332 pp.
- O'Connor, M.P. 1990. Thermoregulation in anuran amphibians: physiology, biophysics, and ecology. Ph.D. Dissertation, Colorado State University.
- O'Connor, M.P. and C.R. Tracy. 1992. Thermoregulation by juvenile toads of Bufo woodhousei in the field and in the laboratory. Copeia 1992(3): 865-876.
- OEA Research. 1985. Wildlife Inventory:Monitoring Report for the CX Ranch Project. 1983-1984. Unpublished report for Consolidation Coal Company, Pittsburgh, Pennsylvania.
- Pack, H.J. 1922. Toads in regulating insect outbreaks. Copeia 107: 46-47.
- Pilliod, D.S. and T.C. Esque. 2023. Amphibians and reptiles. pp. 861-895. In: L.B. McNew, D.K. Dahlgren, and J.L. Beck (eds). Rangeland wildlife ecology and conservation. Cham, Switzerland: Springer. 1023 p.
- Powder River Eagle Studies, Inc., Gillette, WY., 1993, Big Sky Mine 1992 wildlife monitoring. Rev. February 1993.
- Powder River Eagle Studies, Inc., Gillette, WY., 1996, Spring Creek Mine 1995 Wildlife Monitoring Studies. Spring Creek Coal Company 1995-1996 Mining Annual Report. Vol. I, App. I. May 1996.
- Powder River Eagle Studies, Inc., Gillette, WY., 1999, Spring Creek Mine 1998 Wildlife Monitoring. March 1999.
- Powder River Eagle Studies, Inc., Gillette, WY., 2000, Spring Creek Mine 1999 Wildlife Monitoring. March 2000.
- Powder River Eagle Studies, Inc., Gillette, WY., 2000, Spring Creek Mine 2000 Wildlife Monitoring. March 2000.
- Powder River Eagle Studies, Inc., Gillette, WY., 2002, Spring Creek Mine 2001 Wildlife Monitoring. March 2002
- Rauscher, R.L. 1998. Amphibian and reptile survey on selected Montana Bureau of Reclamation impoundments. Montana Department of Fish, Wildlife and Parks, Nongame Program. Bozeman, MT. 24 pp.
- Rauscher, R.L. 2000. Amphibian and reptile survey on selected Montana Bureau of Reclamation impoundments. Unpublished report, Montana Fish, Wildlife & Parks Non-game Program. 12 pp + maps, tables.
- Reichel, J. and D. Flath. 1995. Identification of Montana's amphibians and reptiles. Montana Outdoors 26(3):15-34.
- Reichel, J. D. In prep. Amphibian and reptile survey of USFWS lands in north-central Montana: 1996. Unpublished report.
- Reichel, J.D. 1995b. Preliminary amphibian and reptile survey of the Sioux District of the Custer National Forest: 1994. Montana Natural Heritage Program, Helena, MT. 75 p.
- Reichel, J.D. 1996. Preliminary amphibian and reptile survey of the Helena National Forest: 1995. Montana Natural Heritage Program. Helena, MT. 87 pp.
- Relyea, R.A. 2005a. The lethal impact of Roundup on aquatic and terrestrial amphibians. Ecological Applications 15(4): 1118-1124.
- Roedel, M.D. and P. Hendricks. 1998a. Amphibian and reptile survey on the Bureau of Land Management Lewistown District: 1995-1998. Montana Natural Heritage Program, Helena, MT. 53 p.
- Roedel, M.D. and P. Hendricks. 1998b. Amphibian and reptile inventory on the Headwaters and Dillon Resource Areas in conjunction with Red Rocks Lakes National Wildlife Refuge: 1996-1998. Montana Natural Heritage Program, Helena, MT. 46 p.
- Russell, A. P. and A. M. Bauer. 1993. The amphibians and reptiles of Alberta. University of Calgary Press. Calgary, Alberta. 264 p.
- Ryan, M.J. 1991. Sexual selection and commmunication in frogs. Trends in Ecology and Evolution 6(11): 351-355.
- Shannon, F.A. 1949. A western subspecies of Bufo woodhousei hitherto erroneously associated with Bufo compactilis. Bulletin of the Chicago Academy of Science 8: 301-312.
- Shannon, F.A. and C.H. Lowe. 1955. A new subspecies of Bufo woodhousei from the inland southwest. Herpetologica 11: 185-190.
- Sherman, E. 1980. Ontogenetic change in thermal tolerance of the toad Bufo woodhousii fowleri. Comparative Biochemistry and Physiology A Comparative Physiology 65(2): 227-230.
- Shively, J.N., J.G. Songer, S. Prchal, M.S. Keasey, III and C.O. Thoen. 1981. Mycobacterium marinum infection in Bufonidae. Journal of Wildlife Diseases 17(1): 3-7.
- Spring Creek Coal Company., 1992, Wildlife Monitoring Report. Spring Creek Coal Company 1992 Mining Annual Report. Appendix I.
- Sullivan, B.K. 1982b. Sexual selection in Woodhouse’s toad (Bufo woodhousei) I. Chorus organization. Animal Behavior 30(3): 680-686.
- Sullivan, B.K. 1982c. Significance of site, temperature and call attributes to sexual selection in Bufo woodhousei australis. Journal of Herpetology 16(2): 103-106.
- Sullivan, B.K. 1983a. Sexual selection and mating system variation in the Great Plains toad (Bufo cognatus Say) and woodhouse’s toad (Bufo woodhousei australis Shannon and Lowe). Ph.D. Dissertation, Arizona State University. 138 pp.
- Sullivan, B.K. 1983c. Sexual selection in Woodhouse's toad (Bufo woodhousei). II Female choice. Animal Behaviour 31: 1011-1017.
- Sullivan, B.K. 1985. Sexual selection and mating system variation in anuran amphibians of the Arizona-Sonoran desert. Great Basin Naturalist 45(4): 688-696.
- Sullivan, B.K. 1986a. Hybridization between the toads Bufo microsaphus and Bufo woodhousei in Arizona: morphological variation. Journal of Herpetology 20: 11-21.
- Sullivan, B.K. 1986b. Intra-populational variation in the intensity of sexual selection in breeding aggregations of woodhouse's toad (Bufo woodhousei). Journal of Herpetology 20(1): 88-90.
- Sullivan, B.K. 1989. Interpopulational variation in vocalizations of Bufo woodhousei. Journal of Herpetology 23(4): 368-373.
- Sullivan, B.K. 1995. Temporal stability in hybridization between Bufo microscaphus and Bufo woodhousii (Anura: Bufonidae): Behavior and morphology. Journal of Evolutionary Biology 8(2): 233-247.
- Sullivan, B.K. and G.E. Walsberg. 1985. Call rate and aerobic capacity in woodhouse's toad (Bufo woodhousei). Herpetologica 41(4): 404-407.
- Sullivan, B.K. and M.R. Leek. 1986. Acoustic communication in Woodhouse's toad (Bufo woodhousei): I. Response of calling males to variation in spectral and temporal components of advertisement calls. Behaviour 98(1-4): 305-319.
- Sullivan, B.K. and M.R. Leek. 1987. Acoustic communication in Woodhouse's toad (Bufo woodhousei): II. Response of females to variation in spectral and temporal components of advertisement calls. Behaviour 103(1-3): 16-26.
- Sullivan, B.K. and T. Lamb. 1988. Hybridization between the toads Bufo microscaphus and Bufo woodhousii in Arizona: variation in release calls and allozymes. Herpetologica 44: 325-333.
- Sullivan, B.K., C.R. Propper, M.J. Demlong and L.A. Harvey. 1996a. Natural hermaphroditic toad (Bufo microscaphus x Bufo woodhousii). Copeia 1996(2): 470-472.
- Thompson, L.S. 1981. Circle West wildlife monitoring study: Third annual report. Technical report No. 8. Montana Department of Natural Resources and Conservation. Helena, Montana.
- Thompson, L.S. 1982. Circle West Wildlife Monitoring Study. Fourth annual report. Technical report 10. Montana Department of Natural Resources and Conservation, Helena, Montana.
- Thornton, W.A. 1955. Interspecific hybridization in Bufo woodhousei and Bufo valliceps. Evolution 9: 455-468.
- Thornton, W.A. 1960. Population dynamics in Bufo woodhousei and Bufo valliceps. Texas Journal of Science (12) 176-200.
- Timken, R. No Date. Amphibians and reptiles of the Beaverhead National Forest. Western Montana College, Dillon, MT. 16 p.
- Tran, D.Y., K.V. Hoff and S.D. Hillyard. 1992. Effects of angiotensin II and bladder condition on hydration behavior and water uptake in the toad, Bufo woodhousei. Comparative Biochemistry and Physiology A Comparative Physiology 103(1): 127-130.
- Tucker, J.K. and C.H. Theiling. 1994. Bufo woodhousii fowleri (Fowler's toad). Herpetological Review 25(1): 32.
- Turner, F.B. 1951. A checklist of the reptiles and amphibians of Yellowstone National Park with incidental notes. Yellowstone Nature Notes 25(3): 25-29.
- Turner, F.B. 1955. Reptiles and amphibians of Yellowstone National Park. Yellowstone Interpretive Series No. 5. Yellowstone Library and Museum Association. Yellowstone National Park, WY. 40 p.
- Van Kirk, R., L. Benjamin, and D. Patla. 2000. Riparian area assessment and amphibian status in the watersheds of the Greater Yellowstone Ecosystem. Greater Yellowstone Coalition, Bozeman, MT. 102 p.
- Verma, N. and B.A. Pierce. 1994. Body mass, developmental stage, and interspecific differences in acid tolerance of larval anurans. Texas Journal of Science 46(4) 319-327.
- Vitt, L.J., J.P. Caldwell, and D.B. Shepard. 2005. Inventory of amphibians and reptiles in the Billings Field Office Region, Montana. Sam Noble Oklahoma Museum of Natural History and Department of Zoology, University of Oklahoma, Norman, OK. 33 pp.
- VTN Colorado, Inc. Decker Coal Company., 1975, Draft environmental impact assessment for the proposed North Extension of the West Decker Mine.
- Waage, B.C. 1998. Western Energy Company Rosebud Mine 1997 annual wildlife monitoring report December 1, 1996 to November 30, 1997 survey period. Western Energy Company, Colstrip, MT.
- Waage, Bruce C., 1996, Western Energy Company Rosebud Mine, Colstrip, Montana: 1995 Annual Wildlife Monitoring Report; December 1, 1994 - November 30, 1995. February 28, 1996.
- Waage, Bruce C., 1998, Western Energy Company Rosebud Mine, Colstrip, Montana: 1997 Annual Wildlife Monitoring Report; December 1, 1996 - November 30, 1997 Survey Period. March 23, 1998.
- Waage, Bruce C., 1999, Western Energy Company Rosebud Mine, Colstrip, Montana: 1998 Annual Wildlife Monitoring Report; December 1, 1997 - November 30, 1998 Survey Period. February 24, 1999.
- Waage, Bruce C., 2000, Western Energy Company Rosebud Mine, Colstrip, Montana: 1999 Annual Wildlife Monitoring Report; December 1, 1998 - November 30, 1999. February 2000.
- Waage, Bruce C., 2001, Western Energy Company Rosebud Mine, Colstrip, Montana: 2000 Annual Wildlife Monitoring Report; December 1, 1999 - November 30, 2000. March 30, 2001.
- Waage, Bruce C., 2002, Western Energy Company Rosebud Mine, Colstrip, Montana. 2001 Annual Wildlife Monitoring Report; December 1, 2000 - November 30, 2001. Febr. 26, 2002.
- Waltin, M. 1988. Relationships among metabolic, locomotory, and field measures of organismal performance in the Folwer's toad (Bufo woodhousei fowleri). Physiological Zoology 61: 107-118.
- Wassersug, R.J., A.M. Lum and M.J. Potel. 1981. An analysis of school structure for tadpoles (Anura: Amphibia). Behavioral Ecology and Sociobiology 9(1): 15-22.
- Werner, J.K., B.A. Maxell, P. Hendricks and D.L. Flath. 2004. Amphibians and Reptiles of Montana. Mountain Press Publishing Company: Missoula, MT. 262 pp.
- Western Technology and Engineering, Inc. (WESTECH)., 1997, Wildlife Monitoring Absaloka Mine Area Annual Report, 1996. Montana SMP 85005. OSMP Montana 0007D. Mar. 1997.
- Western Technology and Engineering, Inc. (WESTECH)., 1999, Wildlife Monitoring Absaloka Mine Area Annual Report, 1998. SMP 85005. OSMP Montana 0007E. April 1999.
- Western Technology and Engineering, Inc. (WESTECH)., 2000, Wildlife Monitoring Absaloka Mine Area Annual Report, 1999. Montana SMP 85005. OSMP Montana 0007E. February 2000.
- Western Technology and Engineering, Inc. (WESTECH)., 2001, Wildlife Monitoring Absaloka Mine Area Annual Report, 2000. Montana SMP 85005. OSMP Montana 0007E. February 2001.
- Wheeler, G.C. and J. Wheeler. 1966. The amphibians and reptiles of North Dakota. University of North Dakota, Grand Forks, ND. 104 pp.
- Wied, M.P. 1865. Verzeichniss der reptilien, welche auf einer reise in nordlichen America beobachtet wurden, von Maximilian, Prinzen zu Wied. Eigengangen bei der Akademie am 1, Juni 1865. Druck von E. Blochmann und Sohn, Dresden, Germany. 141 p.
- Witters, L.R. and L. Sievert. 2001. Feeding causes thermophily in the woodhouse's toad (Bufo woodhousii). Journal of Thermal Biology 26(3):205-208.
- Woodward, B.D. 1982. Male persistence and mating success in Woodhouse’s toad (Bufo woodhousei). Ecology 63(2): 583-585.
- Woodward, B.D. 1982. Sexual selection and nonrandom mating patterns in desert anurans (Bufo woodhousei, Scaphiopus couchi, S. multiplicatus, and S. bombifrons). Copeia 1982(2): 351-355. 28.
- Woodward, B.D. 1984a. Arrival to and location of Bufo woodhousei in the breeding pond. Effect on the operational sex ratio. Oecologia 62(2): 240-244.
- Woodward, B.D. 1987b. Interactions between Woodhouse's toad tadpoles (Bufo woodhousei) of mixed sizes. Copeia 1987(2): 380-386.
- Yancey, F.D., II and K.J. Roberts, 1996. Bufo woodhousii woodhousii (Woodhouse's toad) Herpetological Review 27(3):148.
- Yarrow, H.C. 1882. Check list of North American reptilia and batrachia, with catalogue of specimens in the U.S. National Museum. United States National Museum Bulletin 24. 249 p.
- Zweifel, R.G. 1968a. Effects of temperature, body size and hybridization on mating calls of toads, Bufo a. americanus and Bufo woodhousei fowleri. Copeia 1968: 269-285.
- Additional Sources of Information Related to "Amphibians"