Woodhouse's Toad

Anaxyrus woodhousii woodhousii (Bufo woodhousii)

Woodhouse's Toad

Distribution in Wyoming

 

 

 

 

 

 

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The distribution of Woodhouse’s Toad extends from Montana and North Dakota south through the plains into Texas and Mexico, and westerly into Arizona, Utah, and Idaho. In Wyoming it is found in the eastern and north central counties where it inhabits the grassland and sagebrush communities of the prairie and foothill life zones below 6,500 feet. This species prefers loose, porous soils found in irrigated agricultural areas, along the floodplains of lowland streams and rivers, and locations near the permanent water of larger lakes and reservoirs—especially adjacent cottonwood woodlots and sandy beaches. It is primarily nocturnal but is often seen foraging during the day. Its distribution in Wyoming overlaps with the Great Plains Toad and the Plains Spadefoot.

Woodhouse's Toad Woodhouse's Toad

The typical SVL for these toads is 3-4 inches but females with lengths reaching 5 inches are occasionally found. Their dorsal skin is covered with many small, rounded warts which may be tipped with a minute bristle or prickle. These warts are surrounded by a black border which is in turn encircled by a white secondary ring. They have a distinct white stripe running midline along the back. There is considerable color variation but they generally have a foreground of olive, gray, or brown which is contrasted against a lighter background with smudges of green scattered about; this dorsal pattern extends along the sides and onto the legs. The belly is white or cream, free of spots, and has an apron of slightly darker pigmentation covering the pelvic area. (The pelvic patch is a highly vascularized area that facilitates water absorption through the skin.)

Woodhouse's Toad Woodhouse's Toad

The cranial crest consists of two parallel ridges resting between the eyes (interorbital) which diverge laterally just behind the eyes (postorbital), creating a shape similar to a pair of opposing L’s placed back-to-back. This crest distinguishes it from the Great Plains Toad whose cranial ridges merge into the shape of a V as they advance toward the nostrils. The toad is easily identified from the Plains Spadefoot by its dry, glandular skin, the presence of a parotoid gland, and by having rounded rather than elliptical pupils.

Woodhouse's Toad Woodhouse's Toad

Breeding aggregations begin to assemble after spring rains, but such collections may also form in the absence of rains when toads gather along the margins of permanent water bodies or in the pools of low areas flooded by irrigation runoff. Males call while sitting in shallow water by expanding the vocal sac of the throat into a spherical, resonating chamber and issuing a nasal, squalling “whrrrrr” that can be heard from a great distance. Calling activity is greatest in the first few hours after sunset but they are often heard calling during the day. Females seem to prefer larger and louder males. The eggs are laid single file and enclosed within the membrane of a long gelatinous string—actually, as with other species of toads, two strings entwined, each originating from separate oviducts. The string is strewn amongst the submerged vegetation and may be many feet long and contain more than 10,000 eggs. The eggs hatch 2-4 days after fertilization and it takes the resulting tadpoles another 4-7 weeks to complete metamorphosis. Adults reach sexual maturity within 2-3 years.