Small to medium sized toad, with a maximum snout-vent length of 80 mm in females and 75 mm in males. These toads typically possess a pale mark on each sacral hump, and a pale bar extending across the head onto each eyelid. Mid-dorsal stripe is weak or absent. Parotoid glands are rounded. Cranial crests weak, if apparent.
Distribution and Habitat
Country distribution from AmphibiaWeb's database: United States
U.S. state distribution from AmphibiaWeb's database: Arizona, California, New Mexico, Nevada, Utah
The subspecies A. m. microscaphus occurs in a series of isolated populations from the Mogollon plateau of sounthwestern New Mexico to northwestern Arizona, southern Nevada, and southwestern Utah. A. m. californicus ranges from southwestern California to northern Baja, extending into the Mojave desert along the mojave river. A. m. mexicanus is found at high elevations in the Sierra Madre Occidental of Chihuahua, Durango, and Sonora. There is an isolated population along a headwater of the Rio Aguanaval in northwestern Zacatecas. Prefered habitat is near permanent or intermittent shallow water flowing over sandy or rocky substrates, from desert to pine-fir forest. Increasingly common in artificial habitats such as irrigated cropland and reservoirs.
Trends and Threats
Human alteration has allowed A. woodhousii to invade habitat previously occupied only by A. microscaphus. Studies show some indication that A. woodhousii may be replacing A. microscaphus in some drainages.
Possible reasons for amphibian decline
General habitat alteration and loss
See another account at californiaherps.com.
Price, A. H. and Sullivan, B. K. (1963). ''Bufo microscaphus.'' Catalogue of American Amphibians and Reptiles. American Society of Ichthyologists and Herpetologists, 415.1-415.3.
Written by April Robinson (holden AT uclink4.berkeley.edu), UC Berkeley
First submitted 2001-01-31
Edited by Kellie Whittaker (2012-08-15)
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Citation: AmphibiaWeb: Information on
amphibian biology and conservation. [web application]. 2016. Berkeley, California:
(Accessed: Jun 25, 2016).
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