In Alberta, the historical distribution of Canadian Toads encompasses much of the eastern half of the province, with records as far north as the confluence of the Peace and Mikkwa rivers and Fort McMurray, and as far west as Slave Lake, the Rocky Mountain House area, and Calgary. Most records occurred in the northern prairie region and in the aspen
parkland, which no doubt partly reflects the greater number of observers in these areas. The most southerly records occurred near Brooks, with the exception of a single record at Milk River in the 1890s.
The distribution of Canadian Toads in Alberta appears to be confined to regions below 1000 metres in elevation. However, the reason for this pattern is unclear, as numerous environmental variables correlate with elevation. A large proportion of sites where Canadian Toads have been observed are in regions of high groundwater probability. However, without a comparable random sample of sites where toads are not found, it is not possible to ascertain whether toads are disproportionately selecting areas with high groundwater, or whether the apparent preference simply results from there being a large number of relatively wet sites available to Canadian Toads in these areas.
Historically, Canadian Toads have been found in grassland,
parkland and boreal forest regions of the Interior Plains, extending from immediately north of the Alberta/Northwest Territories border near Forth Smith, south to Montana, the Dakotas and Minnesota.
Reprinted from Alberta Wildlife Status Report No. 12 (1998), with permission
from Alberta Sustainable