Summary ²

The western toad (Anaxyrus boreas) more commonly known as Bufo boreas (both names accurate) is a large toad species, between 5.6 and 13 cm long, of western North America. It has a white or cream dorsal stripe, and is dusky gray or greenish dorsally with skin glands concentrated within the dark blotches. Its parotoid glands are oval, widely separated, and larger than the upper eyelids. It has a mottled venter and horizontal pupils but lacks cranial crests.

Distribution and habitat ³

Populations of A. b. halophilus are found in California, w. Nevada, and n. Baja California. Populations of A. b. boreas are found in southern Alaska, British Columbia, Alberta, Washington, Oregon, Idaho, Montana, Wyoming, Colorado, northern California, Nevada, New Mexico, and Utah. This toad frequents a wide variety of habitats such as, desert streams, grasslands, woodlands, and mountain meadows, and can be found in or near a variety of water bodies (Stebbins 1985).

Life history, abundance, activity, and special behaviors ⁴

This species is an explosive breeder. Females deposit thousands of eggs in long strings, usually in shallow ponds. These toads are nocturnal at low elevations and diurnal at higher elevations. During the winter, A. boreas buries itself in loose soil or uses the burrow of a small mammal (Stebbins 1985). This species tends to walk rather than hop. Both males and females lack an advertisement call (Duellman and Trueb 1986) although they are known to have a release call (Brown and Littlejohn 1971).

Sources and Credits

1. (c) J. N. Stuart, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/21786539@N03/4831258337
2. Adapted by Michelle S. Koo from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Anaxyrus_boreas
3. (c) AmphibiaWeb © 2000-2011 The Regents of the University of California, some rights reserved (CC BY), http://eol.org/data_objects/23849664
4. (c) AmphibiaWeb © 2000-2011 The Regents of the University of California, some rights reserved (CC BY), http://eol.org/data_objects/23849665

More Info

• iNat taxon page
• AMNH Amphibian Species of the World
• AmphibiaWeb
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• CalPhotos
• Global Biodiversity Information Facility (GBIF)
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