Adults are usually 110-187mm long from snout to vent. Their olive skin is smooth, leathery, and scattered with small rounded tubercles. Behind the angle of the jaws there is at least one conspicuous white tubercle. The length of each paratoid gland is twice the paratoid width, and equal to the distance from the nostril to the tympanum. On the dorsal surfaces of the limbs there are several enlarged glands that resemble the paratoids. Above each eye curves a distinct cranial crest.
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Mexico, United States
U.S. state distribution from AmphibiaWeb's database: Arizona, California, New Mexico
Found from southern Arizona(USA), through most of Sonora to northern Sinaloa (Mexico). Its range extends into the southeastern parts of California, USA and the northeastern corner of Baja California, Mexico. These toads are primarily found in the desert, but also occur in grassland and lower oak-woodland. They frequently take refuge in rodent burrows. Though they often breed in temporary pools, they appear to be dependant on the presence of a permanent water source.
Life History, Abundance, Activity, and Special Behaviors
These toads appear in Tuscon just prior to the summer showers, and congregate once the rains begin. They breed in temporary pools, croaking incessantly. Males have a reduced vocal sac and their call is weak. Their eggs are strikingly different from those of related species B. boreas and B. canorus. The larval period is believed to be no more than a month. Their diet includes beetles, grasshoppers, spiders, small lizards, Bufo cognatus and Scaphiopus couchi.
Trends and Threats
Habitat destruction and possibly pesticide use have caused populations to become extinct. Collecting by certain groups is also a threat to populations in some areas. Little more is known, therefore conservation efforts are limited.
The glands of the toads produce a toxin that can cause intoxication in humans, and therefore is a controlled substance.
See another account at californiaherps.com.
Fouquette, M. J., Jr (1963). ''Bufo alvarius.'' Catalogue of American Amphibians and Reptiles. American Society of Ichthyologists and Herpetologists, 93.1-93.4.
Written by April Robinson (holden AT uclink4.berkeley.edu), UC Berkeley
First submitted 2001-01-29
Edited by Arie van der Meijden and Vance Vredenburg (2004-04-05)
Species Account Citation: AmphibiaWeb 2004 Incilius alvarius: Sonoran Desert Toad <http://amphibiaweb.org/species/97> University of California, Berkeley, CA, USA. Accessed Jan 21, 2019.
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Citation: AmphibiaWeb. 2019. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Jan 2019.
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