A medium-sized toad, typically characterized by its stocky build and warty skin, common traits among Anaxyrus species. Its coloration varies from gray to greenish or brown, helping it blend into its natural surroundings. Like other toads in its genus, it has prominent parotoid glands that secrete a toxic substance when threatened, which serves as a deterrent to many predators. 

The southwestern toad or Mexican Madre toad (Anaxyrus mexicanus) is endemic to northwestern Mexico, found in the Sierra Madre Occidental in eastern Sonora, western Chihuahua, and southwestern Durango. Its habitat includes riverside locales, desert springs, and other moist areas crucial for its survival in the predominantly arid regions it inhabits. The toad’s ability to thrive in these specific niches, where water is intermittently available, demonstrates significant ecological adaptability.

This toad, like its relatives, is nocturnal, spending the day hidden under rocks or in burrows to avoid the desert heat and retain moisture. It emerges at night to feed mainly on insects, spiders, and occasionally small invertebrates. The diet of the Southwestern toad helps control the populations of potential pest species, highlighting its role in the ecological balance of its habitat. Their breeding is closely tied to the availability of water, occurring typically in temporary pools formed by rain or in riverbeds during the rainy season. The females lay eggs in strings that attach to vegetation in water, where they are somewhat protected from predators. The eggs hatch into tadpoles, which must develop quickly into toadlets before their aquatic habitats dry up, a common challenge in their desert environment.

Distribution

Country

Population est.

Status

Year

Comments

Mexico

2017

Chihuahua, Durango, Sinaloa, Sonora