FWS Focus

Overview

Characteristics
Overview

The Yosemite toad, first discovered in Yosemite National Park, was listed as threatened in 2014. Critical habitat for the species was designated in Alpine, Fresno, Inyo, Madera, Mariposa, Mono and Tuolumne counties, California.

Yosemite toads are stocky, have bumpy skin and range in color from yellowish green to olive green. These toads move by walking instead of hopping. While they use small pools for breeding, the toads spend most of their time in underground burrows to keep cool and hide from predators.

Yosemite toads can be found in the Sierra Nevada from Alpine County, California to Fresno County, California. These toads are still found scattered throughout their historic range in high elevations (8,500 to 10,000 feet). The species is estimated to occur at only 50 percent of historically occupied sites.

Scientific Name

Anaxyrus canorus
Common Name
Yosemite Toad
FWS Category
Amphibians
Kingdom

Location in Taxonomic Tree

Genus

Identification Numbers

TSN:

Characteristics

Characteristic category

Life Cycle

Characteristics
Life Cycle

A unique quality of the Yosemite toad is that it walks instead of hops. Toads can walk up to a mile between burrows and breeding grounds.  

Life Cycle
Reproduction

Breeding season starts in May and extends through July. Males can first breed at 3 to 5 years of age. Females are sexually mature at 4 to 6 years. Females lay approximately 1,500 to 2,000 eggs at a time in a jelly-like group called a clutch.

Life Span

Yosemite toads have a long lifespan – up to 15 years for females and 12 years for males.

Characteristic category

Behavior

Characteristics
Behavior

A unique quality of the Yosemite toad is that it walks instead of hops. Toads can walk up to a mile between burrows and breeding grounds.  

Yosemite toad populations continue to decline because of:

  • Habitat loss: Habitat degradation and loss, especially meadow degradation, caused by grazing, timber and fuels management, recreation and water development. Yosemite toads are sensitive to even minor changes in hydrology and water quality.
  • Disease: Batrachochytrium dendrobatidis, also known as Bd or the amphibian chytrid, is a known cause for amphibian declines worldwide. Although its specific effects on the Yosemite toad are still being researched, the disease has been found in dead Yosemite toads. Because many species closely related to the Yosemite toad have been negatively affected by Bd, it is thought that the fungus will have a detrimental effect on the Yosemite toad population. Bd thrives in cold temperatures and the fungus spores are spread through waterbodies across the Sierra Nevada, where the Yosemite toad is found.
  • Climate change: Yosemite toads have a low tolerance for both extreme cold and hot temperatures - meaning that any climate shift, even slight, could have a negative effect on Yosemite toad populations. In addition, Yosemite toads breed in shallow pools of water, and changes to the temperatures can have an effect on the hydrologic cycle.
  • Mortality: Direct mortality from road crossings and trampling from livestock and packstock.
Characteristic category

Habitat

Characteristics
Habitat

Yosemite toads require two types of habitat. The toad requires slow bodies of fresh water, including wet meadows, slow-moving streams, shallow ponds, springs or shallow areas of lakes for breeding. They also require upland habitat such as conifer forests and the edges of steep slopes for foraging and overwintering. Toads overwinter in upland underground areas such as root tangles at the bases of willows, crevices beneath rocks and stumps and burrows of small mammals. These upland areas provide coverage for the toad from predators, protection from bad weather and a steady supply of food. The toad can travel nearly a mile between the aquatic breeding sites and upland foraging and overwintering sites.

Mountain
River or Stream
Lake
Wetland
Forest

Land covered by evergreen trees in cool, northern latitudes. Also called taiga.

Characteristic category

Food

Characteristics
Food

The Yosemite toad eats different foods throughout its lifecycle. Tadpoles will graze for food at the bottom of shallow waterbodies, eating algae, zooplankton and plant materials. Adult Yosemite toads hunt for food in waterbodies and on land. Adults wait for an invertebrate to approach, and then use their sticky tongue to capture it. Adults eat various small invertebrates such as flies, spiders, ants and beetles.

Characteristic category

Physical Characteristics

Characteristics
Color & Pattern

Males range in color from yellowish green or olive, with few or no spots. Females are lighter in color and have many dark spots on top of a light green back. The throat and belly are pale on both sexes.

Size & Shape

The Yosemite toad is stocky with bumpy skin and widespread legs. Females are often larger than males.

Measurements:Length for both sexes: 1.2 to 2.8 inches (3.0 to 7.1 centimeters)

Weight

Measurements:

Both Sexes: 1.2 to 2.8 inches (3.0 to 7.1 centimeters)

Geography

Characteristics
Range

Yosemite toads can be found in the Sierra Nevada from Alpine County, California to Fresno County, California. These toads are still found scattered throughout their historic range in high elevations (8,500 to 10,000 feet).

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