Sonoran Desert Toad
© 2007 Manny Rubio
The Sonoran Desert Toad (Bufo alvarius) is one of the largest toads native to North America. They are olive green to brown color on their backs, pale underneath with lumpy skin, large lumps on their hind legs, gold-colored eyes with horizontally elliptical pupils, and large, poison-filled paratoid glands behind their eyes.
To avoid the heat of the summer day these toads are nocturnal. To avoid the cool dry winters these toads bury themselves under ground. The spring rains “wake” the toad. The toad survives on fat in its body.
They inhabit grasslands, arid desert lowlands, mountain canyons, and pinyon-oak-juniper mountain forests. They can be found in washes, river bottoms, reservoirs, canals, irrigation ditches, streams, and temporary rain pools.
They are found from southeastern California, northern Mexico, and through southern Arizona to western New Mexico.
These toads are considered to be a species of least concern. The total adult population size for this species is unknown but surely is many thousands. It is common throughout its range.
These toads are carnivorous eating small rodents, reptiles, insects, and even other toads.
Snakes as well as other amphibians prey upon these toads, but they are well protected against predation by mammals. The skin of the toad produces a toxin that reacts with mucous inside a mammals’ mouth. If a dog or other mammal bites onto a toad, it will suffer severe discomfort with the possibility of paralysis and death.
Sonoran Desert toads spend time in the water during the summer, but during the winter months either dig a burrow for themselves or take over an abandoned rodent burrow.
It is estimated that they live 10-20 years in the wild.
These toads can be up to 7 1/2 inches (19 cm) long.
This species is also known as the Colorado River toad.
The female toad will lay an average of 7,500 - 8,000 eggs in still or slow-moving water, in long, single, jelly-coated strings.