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
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
Adults have dry skin with small warts, and are gray, brown, or olive green with paler mottling or spots. A prominent white or yellowish line runs down the center of the back (very young transformed toads typically lack the dorsal line and often have reddish brown warts). Adult body length is 2.5 to 5 inches. Parallel cranial crests are present between the eyes and the post-orbital crests connect them at a right angle behind the eyes; the post-orbital crests typically touch the parotoid glands. If a lump is present on the snout it does not extend back between the eyes. Adults have two black tubercles on each hind foot. Eggs and Tadpoles: Similar to the Western Toad.
The Western Toad lacks cranial crests. The Great Plains Toad has large, white-bordered, dark dorsal blotches. The Canadian Toad has a lump between the eyes and frequently has the parotoid gland separate from the post-orbital crest, which is often broken. Note: it is difficult to distinguish among the four Montana toad species in recently transformed toadlets.
Western Hemisphere Range
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)
Adults are partially terrestrial but usually found near water; they typically breed in permanent lakes, ponds, reservoirs, and slow streams, where they prefer shallow areas with mud bottoms. They are usually found in irrigated agricultural areas and floodplains. Breeding and egg laying is spread out over spring and early summer. Most records are from non-forested eastern MT, but some occur in transition vegetation in ponderosa pine and savannah forests (Black 1970). Found in floodplains and moist grass areas around water (Black 1970, Baxter and Stone 1980).
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: http://mtnhp.org/requests/default.asp
) 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.
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- 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
Known to collect under street-lights and feed on insects. Prey includes virtually every kind of terrestrial invertebrate, and stomach contents can account for up to 16% of body weight. Food habits of early postmetamorphic stages in South Dakota discussed by Flowers and Graves (1995).
Probably most versatile and wide-ranging toads in regard to distribution (Black 1970). Temperatures of 20 to 30 degrees C most favorable for nocturnal activity. During day remain under cover of rocks, or burrowed in soil or damp cover near water (Hammerson 1982). May live over 20 years in the wild (Engeman and Engeman 1996).
Breed late April to July dependent on spring/summer rains. Breed in streams, rivers, irrigation ditches, in shallow water without strong current (Black 1970).
- Literature Cited AboveLegend: View Online Publication
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- Black, J.H. 1970. 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.
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- Hammerson, G.A. 1982. Bullfrog eliminating leopard frogs in Colorado? Herpetological Review 13: 115-116.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
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