U.S. Fish & Wildlife Service

Sacramento Fish & Wildlife OfficeServing the people, conserving the fish, wildlife, and plants of California

A Unit Of The Pacific Southwest Region

Species Information

Picture of Yosemite Toad

Photo Credit: Rob Grasso/NPS

Yosemite Toad

Anaxyrus canorus

Basic Species Information

STATUS

Threatened. The species is likely to become endangered in the foreseeable future throughout all or a significant portion of its range.

DESCRIPTION

The Yosemite toad is a medium-sized toad, usually about 1.2 to 2.8 inches in length. It is found in wet meadows and forests at high elevations (about 4,800 to 12,000 feet), and tends to be most active during the day, usually in sunny areas.

While the male toads are smaller and one solid color, yellow-green to a darker greenish-brown, females have black spots or splotches edged with white or cream, set against a grey, tan, or brown color. Both male and female toads have a rough “warty” skin, and a stocky thick look. They have a stripe down the middle of their back that fades and can disappear with age. Males also have fewer and smaller warts. Eyes are closely set with horizontal pupils. The iris of their eyes is dark brown with gold reflective cells.

Yosemite toads have the largest size difference between males and females of any other North American frog or toad. They both also have slightly oval glands on each side of their head that produce a toxin to help protect them from predators.

Adults are thought to be long-lived, and this factor allows for persistence in variable conditions and more marginal habitats where only periodic good years allow high reproductive success. Females have been documented to reach 15 years old, and males as many as 12 years. However, the average longevity of the Yosemite toad in the wild is not known.

FOOD SOURCES

The Yosemite toad diet consists of a wide variety of invertebrates: beetles; ants; spiders; bees; wasps; flies; and millipedes. Their prey is located by vision, then the toad lunges while deploying a large sticky tongue to catch the prey.

HABITAT

Yosemite toads are usually in sunny areas, where basking in sunlight is needed to maintain an optimal body temperature. In hotter, drier months they can often be found in moister areas within or near the meadow, including within natural cover or even cattle hoofprints. They use spaces under surface objects, including logs and rocks, for temporary refuge.

During their terrestrial lifestages, Yosemite toads use rodent burrows for overwintering. Males and females likely inhabit different areas and habitats when not breeding, but usually they are not more than a about 300 feet from permanent water. Females tend to move farther from breeding ponds than males. The majority of their life is spent in the upland habitats close to their breeding meadows.

HIBERNATION

Their activity period is relatively short, from April through July to late September or early October. During winter, Yosemite toads shelter in the burrows of small mammals, willow thickets, forest edges adjoining meadows, and in clumps of vegetation near water.

MATING

Mating and egg-laying take place from May to July, shortly after the snow melts in shallow pools in meadows, the margins of lakes and quiet streams. Females are reproductively mature at four to six years of age, but do not breed every year. Males first breed when they are three to five years old.

The reproductive cycle is similar to that of most North American frogs and toads. Males arrive at breeding sites a few days before females. Males stay for one to two weeks, while females leave after a few days.

Males set up a territory in shallow water and make a trilled breeding call to attract a female. Part of the species name, the specific epithet “canorus” means 'tuneful' in Latin, referring to the male's sustained melodious trill. Calls are made during the day, peaking at midday. Calling males at breeding sites will defend their territory against intrusion by other males. When a female arrives, the male grasps the back of the female and hangs on until she finds a location where she decides to lay her eggs. The male releases sperm externally to fertilize the eggs as the female lays them.

Darkly-pigmented eggs are laid in strings of single or double strands or in a radiating network several eggs deep in shallow pools and slow moving meadow streams. Females have been known to lay an estimated 1,500 to 2,000 eggs at one location.

After mating and egg deposition, males and females move from the breeding pond into meadows where they feed for two to three months before the snows return. The eggs hatch into tadpoles in 10 to 12 days. The tadpoles, which feed in the water, eventually grow four legs, lose their tails, and emerge onto land where they disperse into the surrounding territory in a relatively short period of time (5-7 weeks).

RANGE

Indigenous to California, Yosemite toads are found in a 150 mile span of the Sierra Nevada Mountains from Ebbetts Pass in Alpine County in the north to Fresno and northern Inyo Counties in the south.

Once abundant, this species has been in dramatic decline for several decades and is now found primarily on publicly managed lands at high elevations, including streams, lakes, ponds, and meadow habitats located within national forests and national parks.

THREATS

Threats to the Yosemite toad include destruction, modification, and curtailment of the species' habitat and range. Studies show that the toad has seen range-wide declines in habitat occupancy estimated at almost 50 percent, by watershed. Remaining populations are invariably small and at greater risk of extirpation by various threat factors.

Past land uses have altered meadow communities by permanently reducing habitat quantity and quality unless active and costly restoration is implemented. Climate change is a current threat of high magnitude and predation by ravens is a threat of increasing concern. In addition, there is ongoing research on the role of chytrid fungus in historical declines of the Yosemite toad.

WHAT YOU CAN DO

Wherever you live in California, there are zoos and nature centers where you can see and learn about toads.

Need more specifics? Download the Yosemite toad scientific species account.

Last updated: November 30, 2017