Colorado River Toad

Characteristics

This is the largest western toad at 4-7.5 inches long. It is chunky and short-legged, with dark olive-green leathery skin above and a smooth creamy-white underside. It has a prominent cranial crests, and an enlarged whitish wart near the angle of the jaw. Both males and females have pale throats. Its vocal sac is absent or vestigial. Its voice is weak and low-pitched, resembling a ferryboat whistle.

Species Specifics

Physical Characteristics

Ecology

Habitat

Occurs in a variety of habitats including creosote bush ( a desert scrub), grasslands, oak-pine woodlands, thornscrub, and tropical deciduous forest.

Distribution

Ranges from arid mesquite lowlands and arid grasslands into the groves in mountain canyons. Often found near permanent springs, reservoirs and streams. Ranges include southern Colorado across Arizona to extreme southwestern New Mexico. Also found in northwestern Sinaloa to extreme southeastern California.

Diet

Carnivorous. Insects, spiders, beetles, grasshoppers, lizards, rodents, and other toads.

Ecological Web

Secondary consumer. Also controls crop pests such as snails.

Activity and Behavior

Activity Pattern

Nocturnal. The Colorado River Toad remains underground during the heat of the day. Activity is stimulated by rainfall, but is not dependent on rainfall for breeding. Most active from May-July, (living in burrows under the ground during the winter). Breeding usually occurs in spring and summer. Colorado River Toads are more aquatic than most toad species.

Behavior

Social Behavior

Solitary. This toad is a solitary species until the mating season in the summer months, when large groups of toads gather at temporary pools to mate.

Reproductive Behavior

Colorado River Toads appear when the summer showers start and breed in the temporary pools that form after the rains begin. Mating occurs from May to July. Males croak incessantly, but have a relatively weak call, compared to other frogs and toads. The female lays strands of black eggs. There can be as many as 8,000 eggs in a single strand! The tadpoles hatch within 2-12 days. After the breeding season is over, this toad will return to its burrow where it will spend the winter.

Offspring

Born as yellow-brown tadpoles, but quickly grow into toadlets after about one month.

Conservation

Status

Not endangered in most of its range, but near extinction in California. Listed as a species of Least Concern by IUCN. However, in California the toad is classified as Endangered and in New Mexico it is considered Threatened.

Historical

Historically its range extended throughout southeastern California, though it has not been seen there since the 1970's.

Current Threats

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