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 Arizona Toad occurs in a series of isolated populations from the Mogollon plateau of southwestern New Mexico to northwestern Arizona, southern Nevada, and southwestern Utah. Preferred 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 Anaxyrus 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
Former subspecies A. m. californicus, which ranges from southwestern California to northern Baja, extending into the Mojave desert along the Mojave river, is now considered A. californicus. Former subspecies A. m. mexicanus is found at high elevations in the Sierra Madre Occidental of Chihuahua, Durango, and Sonora (Stebbins 2003).
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.
Stebbins, R. C. (2003). Western Reptiles and Amphibians, Third Edition. Houghton Mifflin, Boston.
Originally submitted by: April Robinson (first posted 2001-01-31)
Distribution by: Michelle S. Koo (updated 2021-06-03)
Trends and threats by: Michelle S. Koo (updated 2021-06-03)
Comments by: Michelle S. Koo (updated 2021-06-03)
Edited by: Kellie Whittaker, Michelle S. Koo (2021-06-03)
Species Account Citation: AmphibiaWeb 2021 Anaxyrus microscaphus: Arizona Toad <https://amphibiaweb.org/species/237> University of California, Berkeley, CA, USA. Accessed Jul 31, 2021.
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Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 31 Jul 2021.
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