Western (Boreal) Toad

AARC Blog #3
Dr. Teresa Bousquet
Exotic Animal Veterinarian and AARC Board Member

Creature Feature – Western (Boreal) Toad Anaxyrus boreas

One of my first Alberta herping experiences was at the Wagner Bog with my friend, and fellow AARC Board Member, Ian Kanda. It was a late summer evening, shortly after dark, and we were looking for Boreal Toads.

There are 3 native toad species in Alberta: the Canadian Toad, The Great Plains Toad, and The Western Toad. True toads have “warty” skin, little webbing between the toes, enlarged parotid glands, and prominent tubercles on their feet for digging. In addition to our “true” toads, we also have the Plains Spadefoot Toad, which is not as warty as the other species, and lack the parotid gland.

Western Toads are native to western North America. In Canada, they are found in British Columbia, Alberta, Yukon and Northwest Territories. In Alberta, they are found primarily in the western and central part of the province. They tend to live near lakes, streams and ponds in boreal, foothill and mountain regions. Adults feed on slugs, worms, and insects, while tadpoles are algae eaters. They are the largest of Alberta’s toads, ranging from 2-5” in length. The average lifespan for a Western Toad is 9-11 years

Male Western Toads are sexually mature at 3 years, while the females are mature at 4-5 years. At breeding sites, males can out-number females 20 to 1. It is thought that this ratio may be related to the size of the egg clutches produced. Western Toads are described as “explosive” breeders, with females producing 5000-15000 eggs at a time. It is thought that this effort is so energetically draining that females can only breed every few years.

Western Toads populations are considered “Sensitive” in Alberta.

http://esrd.alberta.ca/fish-wildlife/wild-species/amphibians/toads/western-toad.aspx
http://www.sararegistry.gc.ca/species/speciesDetails_e.cfm?sid=748