Great Plains Toad
Scientific Name: Anaxyrus cognatus
Other/Previous Names: Bufo cognatus
Taxonomy Group: Amphibians
Range: Alberta, Saskatchewan, Manitoba
Last COSEWIC Assessment: April 2010
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Special Concern
Image of Great Plains Toad
The adult toad is large and broad, with a body length of 4.5 to 10 cm for males, and 5 to 11 cm for females. The back is covered by numerous tubercles or "warts," most of which are less than 1 mm in diameter. It varies in colour from greenish to brown, brown-yellow, or grey, with conspicuous blotches. The blotches are usually paired, and can be rounded or irregular in shape. Dark brown to olive in colour, they have well-defined narrow borders. The belly is almost always uniformly white or cream in colour, and is rarely spotted. Breeding males have a black vocal sac; when expanded, it is sausage-shaped and extends above and beyond the snout. The breeding call of the toad is a loud, "metallic-sounding" trill. Newly hatched tadpoles are black and range in size from 1 to 4 mm. As the larvae develop, the belly becomes iridescent and lighter in colour.
Distribution and Population
The Great Plains Toad occurs throughout an extensive range in western North America and the northern half of Mexico. In Canada, it is likely widely distributed throughout the area bounded by the Saskatchewan border to the east, the Trans-Canada Highway and Alberta Provincial Highway No. 3 to the south, the Taber-Vauxhall-Lake Newall area to the west, and the Red Deer River to the north. In Alberta, the species is restricted to the southeastern grasslands; in Saskatchewan, most of the few records are near the Alberta border. In recent years (1983 on), there have been reports of the species in extreme southwestern Manitoba. In Alberta, past concerns about declining populations may have been due to lack of investigation during years of higher precipitation, when the species can be detected more readily. More recent surveys (1994, 1996) suggest there are large numbers of the toad at Suffield National Wildlife Area (NWA), Alberta. No information is available to assess the size or trend of populations in Saskatchewan or Manitoba.
The Great Plains Toad breeds mainly in temporary wetlands that fill with water following heavy rains in late spring and early summer. At Suffield NWA, breeding sites were associated with large, shallow, seasonal wetlands with limited residual growth and some new emergent grass along the margins. During periods of extended drought in Alberta, the toads appear to rely upon irrigated areas for breeding habitat.
The Great Plains Toad is primarily nocturnal. Research in Oklahoma suggests that there is a high correlation between precipitation and breeding in this species. Breeding does not occur in the absence of rain, even in irrigated areas. The amount of rain that stimulates breeding activity can vary considerably, and the actual breeding can be delayed until the air temperature has reached 12°C or more. Males arrive at breeding ponds in Suffield NWA in early May and commence a chorus of breeding calls, beginning nightly about 45 minutes after sunset and continuing until dawn. Calling males concentrate along the fringes of shallow wetlands where grasses and sedges stick out of the water. A female usually approaches a calling male by swimming underwater. The male climbs on the female’s back and remains there until egg-laying has been completed some 24 hours later. The pair moves together to an appropriate egg-laying site. The male uses his legs or feet to gather the eggs as they are being laid by the female and fertilizes them before they are released. Larger females lay more eggs than smaller females, but even an average-sized female can lay about 20 000 eggs. The larval development period is typically about 45 days, but is decreased when the water temperature is warmer. Tadpoles are about 11 to 13 mm long at the time of metamorphosis (transformation to adult/toad stage). Metamorphosis is highly synchronous (occurring at the same time), but often unsuccessful. Many tadpoles die because the breeding pools frequently dry up. However, toads can avoid dry conditions, including high air temperature with low humidity, by burrowing into the soil beneath the water surface. The heart rate decreases (brachycardia) and there is a shift to anaerobic metabolism, to cope with the lack of oxygen during burrowing.
Grassland habitat may be widely available for this species within its range, but many areas of grassland may not include depressions (such as sloughs) suitable for breeding when high spring runoff or heavy rains trigger breeding. Progressive conversion of grasslands to cropland, application of herbicides and pesticides, and local impacts by grazing, may be slowly reducing the quantity and quality of available habitat.
Federal ProtectionMore information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
In Alberta, the Great Plains Toad is afforded protection as a non-game animal. It cannot be killed for any reason, cannot be bought or sold, and a permit is required for holding one in captivity for educational or scientific purposes. In Saskatchewan, any person may collect, study, hunt, and hold in captivity, without a licence, any toad that is not in a protected area (game preserve, wildlife refuge, regional park, and provincial park or recreation site). In Manitoba, it is covered under a ministerial amendment to the provincial Wildlife Act. Large areas of grassland habitat are associated with federal and provincial pastures, parks, and military reserves, and these are protected from conversion to cropland.
Provincial and Territorial Protection
Recovery Progress and Activities
Summary of Progress to Date A multi-jurisdictional team is being assembled to prepare a management plan for the Great Plains Toad in Alberta, Saskatchewan, and Manitoba. Summary of Recovery Activities A stewardship guide for landowners has been developed by the Alberta Conservation Association and distributed to landowners. It outlines beneficial management practices for species at risk, including the Great Plains Toad. Some 200 hectares of native riparian habitat are being secured through perpetual conservation agreements.
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
13 record(s) found.
- COSEWIC Status Reports (2 record(s) found.)
- COSEWIC Assessments (2 record(s) found.)
- Response Statements (2 record(s) found.)
- Management Plans (1 record(s) found.)
- Orders (3 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (2 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2010 (2010)Under Canada’s Species At Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. During the past year, COSEWIC held two Wildlife Species Assessment Meetings and reviewed the status of 79 wildlife species (species, subspecies, populations). During the meeting of November 2009, COSEWIC assessed or reviewed the classification of the status of 28 wildlife species. COSEWIC assessed or reviewed the classification of an additional 51 wildlife species (species, subspecies and populations) during their April 2010 meeting. For species already found on Schedule 1 of SARA, the classification of 32 species was reviewed by COSEWIC and the status of the wildlife species was confirmed to be in the same category (extirpated - no longer found in the wild in Canada but occurring elsewhere, endangered, threatened or of special concern). The wildlife species assessment results for the 2009-2010 reporting period include the following: Extirpated: 6 Endangered: 39 Threatened: 16 Special Concern: 17 Data Deficient: 1 This report transmits to the Minister the status of 46 species newly classified as extirpated, endangered, threatened or of special concern, fulfilling COSEWIC’s obligations under SARA Section 24 and 25. A full detailed summary of the assessment for each species and the reason for the designation can be found in Appendix I of the attached report. Since its inception, COSEWIC has assessed 602 wildlife species in various risk categories, including 262 Endangered, 151 Threatened, 166 Special Concern and 23 Extirpated. In addition, 13 wildlife species have been assessed as Extinct. Also, to date, 46 wildlife species have been identified by COSEWIC as Data Deficient and 166 wildlife species were assessed as Not at Risk. This year has been a particularly productive year for COSEWIC’s Aboriginal Traditional Knowledge (ATK) Subcommittee. In April 2010 COSEWIC approved the Aboriginal Traditional Knowledge Process and Protocol Guidelines, providing clear and agreed principles for the gathering of Aboriginal Traditional Knowledge to carry out COSEWIC functions as required under Section 15(2) of SARA (See Appendix III of the attached report). We are grateful for the rich and enthusiastic contribution made by community elders and experts in helping the ATK Subcommittee prepare the ATK protocols.
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