The boreal toad is Colorado's only alpine species of toad. Females generally grow to 11 centimeters and males to 9 centimeters. Both sexes appear warty and usually have a light stripe along the middle of the back. Juveniles may have red warts.
Range: The species occurs throughout most of western North America, from southeastern Alaska to northern Baja California, Utah and northern New Mexico. The distinct Southern Rocky Mountain population is distributed from southern Wyoming to southern Colorado, and is currently believed to be extirpated from northern New Mexico. In Colorado, the boreal toad is distributed throughout the Rockies from the northern state border to Mineral and Hinsdale counties in the south at elevations between 7,500 and 12,000 feet.
Habitat: Distribution of the boreal toad is restricted to areas with suitable breeding habitat in spruce-fir forests and alpine meadows. Breeding habitat includes lakes, marshes, ponds, and bogs with sunny exposures and quiet, shallow water.
Diet: Boreal toads feed on a wide range of invertebrates and insects, including flies, mosquitoes, grasshoppers, beetles and moths.
Reproduction: Toads breed in still waters in marshy areas from May to late July. Unlike many species of toad, the boreal does not have a loud mating call. Males will emit a soft chirp, and sometimes call in groups. Females typically lay 3,000 to 8,000 eggs and larvae development takes two months or more.