COSEWIC status report on the Great Plains toad Bufo cognatus in Canada in COSEWIC assessment and status report on the great plains toad Bufo cognatus in Canada
Publication Type: |
Journal Article |
Year of Publication: |
1999 |
Authors: |
Andrew B. Didiuk |
Publication/Journal: |
|
Keywords: |
anuran, bufo cognatus, canada, great plains toad, population size, wildlife protection legislation |
Abstract:
Executive Summary: The Great Plains toad, Bufo cognatus, is a widely-distributed species in western North America. In Canada, it is restricted to south-eastern Alberta, southern Saskatchewan, and extreme south-western Manitoba where it is associated with mixed-grass prairie.
Bufo cognatus is a grassland anuran adapted to survive and breed under xeric conditions. Fossorial habits and relatively long life allow it to disperse widely and survive extended periods of drought and the freezing temperatures of winter. When suitable breeding wetland conditions become available enormous numbers of young toads may be produced, but limited information suggests high overwinter mortality of juveniles is probably common.
In Alberta past concerns about declining populations may have been due to lack of investigation during years of higher water when the species can be detected more readily. Recent surveys suggest large numbers of B. cognatus occur at Suffield National Wildlife Area, Alberta. No information is available to assess the size or trend of populations in Saskatchewan or Manitoba.
Grassland habitat may be widely available for B. cognatus within its range, but many areas of grassland may not include depressions suitable for breeding when high spring runoff or heavy rains stimulate breeding. Progressive conversion of grasslands to cropland, and local impacts by grazing, may be slowly reducing quantity and quality of habitat.
Currently no federal or provincial protective legislation applies specifically to B. cognatus. No information is available to indicate the relative effectiveness of current wildlife protection legislation in terms of protecting the Great Plains toad and its habitat.