A Guide to the Amphibians
and Reptiles of California

Yosemite Toad - Anaxyrus canorus

(Camp, 1916)

(= Bufo canorus)

Click on a picture for a larger view

Description • Taxonomy • Species Description • Scientific Name • Alt. Names • Similar Herps • References • Conservation Status

Red: Historical Range in California

Click on the map for a topographical view

Map with California County Names

Listen to this toad:

One short call

More Sounds of
Yosemite Toad

Breeding, Eggs,
and Tadpoles

Adult Males

Adult male, Alpine County

Adult Male, Alpine County

Adult male in calling position, Alpine County, hunkered down in a small self-made cavity in a meadow.

Adult male, Alpine County

Adult male, Mono County
© Douglas Aguillard

This adult male sat at the edge of a small trickle at the edge of a small lake in Alpine County for several hours, probably feeding on insects.

Adult male, Alpine County

Male, Tuolumne County
© Paul Maier

Adult male, raised up in a defensive stance, Alpine County © Richard Porter

Adult female (left) and male,
Fresno County © Patrick Briggs

Male, Tuolumne County
© Paul Maier

Male Yosemite Toads With an Unusual Appearance

Male with unusually reddis coloration, Tuolumne County © Paul Maier

Melanistic adult male, Mariposa County
© Paul Maier

Oddly-pigmented male in pond with tadpoles, Mariposa County © Paul Maier

Adult male with unidentified dorsal black spots, possibly from a disease, parasite, or genetic mutation, Fresno County
© Paul Maier

Adult Females

Adult Female, Alpine County

Adult female in a small meadow cavity, Alpine County

Adult female, Mono County
© Ben Witzke

Adult female, Fresno County
© Paul Maier

Adult female wedged between two snow banks while migrating to the breeding pond Tuolumne County © Paul Maier

Adult female, Tuolumne County
© Paul Maier

Very dark adult female with a lot of black coloring,
Mono County © Andrew de Koeyer

Adult female, Fresno County
© Paul Maier

Juveniles

Juvenile, Alpine County

Juvenile, showing typical orange tubercles on the palms of their hands and feet, Fresno County © Paul Maier

Juvenile, Tuolumne County
© Paul Maier

Reproduction, Eggs, and Tadpoles
(See More Pictures Here)

Adults in amplexus with the female depositing her eggs, Alpine County

Calling male, Alpine County

Eggs, Fresno County
© Julie Nelson

Tadpoles, Alpine County

Habitat

Habitat, 8,900 ft, Alpine County

Breeding habitat, 8900 ft., Alpine County (site of amplexing adults and eggs shown above is in shallow water at lower left)

Habitat, Alpine County

Toad in habitat in late summer (in the center of the photo on the bank of a small creek) 8,800 ft., Alpine County.

Adult male, Alpine County, (at very bottom of pictures) at edge of snow-melt runoff in a meadow in which there are a few calling males during the beginning of the breeding season.

Tadpoles habitat, 8,900 ft,. Alpine County

Habitat, Alpine County

Habitat at breeding time - meadow saturated with
snow melt 8,900 ft., Alpine County.

Former habitat, 9,100 ft. Mono County

Habitat, Mono County © Ben Witzke

Two views of breeding habitat at 9200 ft. elevation in Fresno County
during the breeding period just after snow melt in late May.

Subalpine habitat in breeding season, with pond in foreground showing tadpole divots, Fresno County © Paul Maier

Habitat in breeding season,
Mariposa County © Paul Maier

Subalpine habitat, Tuolumne County
© Paul Maier

Transitional habitat, Tuolumne County
© Paul Maier

Montane habitat, Tuolumne County
© Paul Maier

Short Videos

Male Yosemite Toads swim and hop around a meadow surrounded by melting snow.

Juvenile and adult male Yosemite Toads around a high-elevation lake.

This is a 20 second video of a male toad calling in the afternoon from a snow-melt pool in a high-altitude wet meadow surrounded by snow at 9200 ft. elevation in Fresno County. The air temperature was 37 degrees, but the shallow water was over 60 degrees F. due to the sun. Pacific Treefrogs and water sounds are heard in the background.

Many thanks to Stephanie Weber, aquatic biologist and toad Muse, for helping me to get this recording by inspiring some cold and sluggish toads to call.

This is a short video of a male and female in amplexus in Fresno County. A release call, probably made by the female (on the bottom), can be heard as the frogs hop together. A female typically produces this call after she has already laid her eggs and wants the male to release her.
© Julie Nelson

These are short videos of a male calling from on top of and underneath
a piece of buried tree root in a wet meadow in Alpine County.

Tiny recently-hatched tadpoles swim in shallow puddles in a high mountain meadow in Alpine County

A juvenile toad in Alpine County.

A short video of adults in amplexus hopping around the breeding pond in Tulumne County. You can hear the female making a faint release call.
© Paul Maier

Description

Size

Adults are 1.25 - 2.74 inches from snout to vent ( 4.4 - 6.9 cm). (Stebbins, 2003)

Appearance

A robust and stocky toad with dry, uniformly warty skin.
No cranial crests are present.
Paratoid glands are large, flat, and oval.
Eyes are closely set with horizontal pupils.
A dorsal stripe is very faint or absent.

Color and Pattern

Male and females are very different in appearance.

Males are pale yellowish green or olive above, with few or no dark blotches.
Females and young are heavily blotched on a light background.
The throat and belly are pale on both sexes.

Male/Female Differences

Besides the differences in color and pattern described above, males are smaller than females and have fewer and smaller warts.

Young

Young have no dorsal stripe immediately after transformation.
The bottoms of their feet is bright orange or yellow.

Larvae (Tadpoles)

Tadpoles are very dark brown, possibly as a protection from ultraviolet solar radiation which is very strong at the high elevation locations inhabited by these toads
Eyes are inset from the edges of the head on the top.
The tip of the tail is rounded.
Tadpoles grow to about 1.5 inches (3.7 cm) in length before undergoing metamorphosis. (Stebbins & McGinnis 2012)

Life History and Behavior

Activity

Active mostly in daytime, usually in sunny areas, where basking in sunlight is needed to maintain an optimal body temperature.
Activity period is relatively short, from April - July, to late September - early October.

Overwintering

During winter, Yosemite Toads shelter in the burrows of small mammals, willow thickets, forest edges adjoining meadows, and in clumps of vegetation near water.

Movement

Like most toads, this one is slow moving, often using a walking or crawling motion along with short hops.

Defense

For defense Yosemite toads rely on parotoid glands and warts which can secrete a poison that deters some predators.
They may also retreat into burrows or jump into water to hide from threats.

Territoriality

Calling males at breeding sites will defend their territory against intrusion by other males.

Longevity

Kagarise Sherman and Morton (1984) estimated that females may live at least 15 years and males at least 12 years.
(Kagarise Sherman, 1980 - referenced in Davidson and Fellers, Lanoo 2005)

Voice (Listen)

A long, loud, rapid musical trill, repeated at frequent intervals.

Diet

Diet consists of a wide variety of invertebrates, including beetles, ants, siders, bees, wasps, flies, and millipedes. The prey is located by vision, then the toad lunges with a large sticky tongue to catch the prey and bring it into the mouth to eat.

Reproduction

Reproduction is aquatic.
Fertilization is external, with the male grasping the back of the female and releasing sperm as the female lays her eggs.
Amplexus is axillary - the male grabs the female around her shoulders or arpits.

The reproductive cycle is similar to that of most North American Frogs and Toads. Mature adults come into breeding condition and migrate to ponds or ditches where the males call to advertise their fitness to competing males and to females. Males and females pair up in amplexus in the water where the female lays her eggs as the male fertilizes them externally. The adults leave the water and the eggs hatch into tadpoles which feed in the water and eventually grow four legs, lose their tails and emerge onto land where they disperse into the surrounding territory.

Females are reproductively mature at 4–6 years of age, but do not breed every year.
Males first breed when they are 3–5 years old. (Kagarise Sherman, 1980 - referenced in Davidson and Fellers, Lanoo 2005)

Mating and egg-laying takes place from May to July shortly after the snow melts in shallow pools in meadows, the margins of lakes and quiet streams.
Males arrive at breeding sites a few days before females. (Males stay for 1 - 2 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. Calls are made during the day, peaking at mid day. When a female arrives, the male amplexes her and rides her to a location where she decides to lay her eggs.

Eggs

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 laid an estimated 1,500 to 2,000 eggs at one location.
Eggs hatch in 10 - 12 days.

Tadpoles and Young

Tadpoles metamorphosed in 52 - 63 days at one location.
Tadpoles are preyed upon by other frogs, birds, diving beetles, and probably gartersnakes.

Juvenile toads feed and overwinter near the breeding pond, in small burrows or root tangles.

Hybrids

Hybridizes with A. b. halophilus in the northern part of its range. (Stebbins 2003.)

Habitat

Inhabits wet mountain meadows, willow thickets, and the borders of forests, usually not more than a hundred meters from permanent water.
After breeding, males and females move from the breeding pond into meadows where they feed for 2 - 3 months before the snows return.

Geographical Range

Endemic to California.
Found only at high elevations in the Sierra Nevada Mountains.
Most authors indicate that the distribution is from the Ebbets Pass area of Alpine County south to the Spanish Mountains area in Fresno County, but there are mentions of Yosemite Toads from farther north than Ebbets Pass: Stebbins (2003/2012) notes their northernmost range as Grass Lake, El Dorado County (just north of the Alpine County line) and there are museum specimens from 1956 taken from Fallen Leaf Lake, El Dorado County, which is just south of Lake Tahoe.

Range map information courtesy of Paul Maier, San Diego State University.

Elevational Range

Found at elevations of 4,800 - 12,000 ft. (1,460 - 3,630 m.) (Stebbins & McGinnis, 2012)

Notes on Taxonomy

Formerly included in the genus Bufo. In 2006, Frost et al replaced the long-standing genus Bufo in North America with Anaxyrus, restricting Bufo to the eastern hemisphere. Bufo is still used in most existing references (in 2013).

Alternate and Previous Names (Synonyms)

Bufo canorus - Yosemite Toad (Stebbins 1954, 1966, 1985, 2003, Stebbins & McGinnis 2012)
Bufo canorus - Yosemite Toad (Yosemite Park Toad) (Wright and Wright 1949)
Bufo canorus - Yosemite Park Toad (Storer 1925)
Bufo canorus - Yosemite Park Toad (Grinnell and Camp 1917)
Bufo canorus (Camp 1916)

Conservation Status

It has been estimated from population studies that the Yosemite Toad has disappeared from over 50% of its historic range, even in habitats that still appear to be unaltered. Remaining populations may not be reproducing enough to survive. One population at Tioga Pass, counted for more than 20 years, had declined by 90 percent in 1993.

The causes of the decline are unclear. Disease, degradation of habitat by grazing livestock, increased ultraviolet radiation, introduced predatory fishes, a severe 1980's drought, windborne pesticide contamination, and increased predation by Common Ravens, whose population has increasd greatly due to human activities, are all causes which are thought to have contributed to the decline.

Proposed for Federal ESA Threatened listing 4/25/13.
Federally listed as Threatened under the Endangered Species Act 4/25/14.

In August, 2016, the U.S. Fish and Wildlife Service announced the designation of 1.8 million acres of protected critical habitat in the Sierra Nevada mountains for Rana sierrae, the Sierra Nevada Yellow-legged Frog, the northern population of Rana muscosa, the Southern Mountain Yellow-legged Frog, and Anaxyrus canorus, the Yosemite Toad. BiologicalDiversity.org

Taxonomy
Family	Bufonidae	True Toads	Gray, 1825
Genus	Anaxyrus	North American Toads	Tschudi, 1845
Species	canorus	Yosemite Toad	(Camp, 1916)
Original Description
Bufo canorus Camp, 1916 - Univ. California Publ. Zool., Vol. 17, No. 6, p. 59 from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
Meaning of the Scientific Name
Bufo - toad Anaxyrus - Greek - A king or chief canorus - Latin for tuneful - "melodious trill uttered by this toad" - referring to the male's breeding call Taken in part from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
Related or Similar California Frogs
Anaxyrus boreas boreas Anaxyrus boreas halophilus Anaxyrus woodhousii Anaxyrus californicus Anaxyrus exsul
More Information and References
NatureServe Explorer AmphibiaWeb California Department of Fish and Game Stebbins, Robert C., and McGinnis, Samuel M. Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012. Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972. Flaxington, William C. Amphibians and Reptiles of California: Field Observations, Distribution, and Natural History. Fieldnotes Press, Anaheim, California, 2021. Samuel M. McGinnis and Robert C. Stebbins. Peterson Field Guide to Western Reptiles & Amphibians. 4th Edition. Houghton Mifflin Harcourt Publishing Company, 2018. Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003. Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992. Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998. Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Amphibians of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009. Elliott, Lang, Carl Gerhardt, and Carlos Davidson. Frogs and Toads of North America, a Comprehensive Guide to their Identification, Behavior, and Calls. Houghton Mifflin Harcourt, 2009. Lannoo, Michael (Editor). Amphibian Declines: The Conservation Status of United States Species. University of California Press, June 2005. Storer, Tracy I. A Synopsis of the Amphibia of California. University of California Press Berkeley, California 1925. Wright, Albert Hazen and Anna Wright. Handbook of Frogs and Toads of the United States and Canada. Cornell University Press, 1949. Basey, Harold E. Discovering Sierra Reptiles and Amphibians. Yosemite Association and Sequoia Natural History Association, 1976, 1991. Davidson, Carlos. Booklet to the CD Frog and Toad Calls of the Pacific Coast - Vanishing Voices. Cornell Laboratory of Ornithology, 1995. Robert C. Thomson, Amber N. Wright, and H. Bradley Shaffer. California Amphibian and Reptile Species of Special Concern. University of California Press, 2016. Joseph Grinnell and Charles Lewis Camp. A Distributional List of the Amphibians and Reptiles of California. University of California Publications in Zoology Vol. 17, No. 10, pp. 127-208. July 11, 1917.

Conservation Status
The following conservation status listings for this animal are taken from the January 2024 State of California Special Animals List and the January 2024 Federally Listed Endangered and Threatened Animals of California list (unless indicated otherwise below.) Both lists are produced by multiple agencies every year, and sometimes more than once per year, so the conservation status listing information found below might not be from the most recent lists. To make sure you are seeing the most recent listings, go to this California Department of Fish and Wildlife web page where you can search for and download both lists: https://www.wildlife.ca.gov/Data/CNDDB/Plants-and-Animals. A detailed explanation of the meaning of the status listing symbols can be found at the beginning of the two lists. For quick reference, I have included them on my Special Status Information page. If no status is listed here, the animal is not included on either list. This most likely indicates that there are no serious conservation concerns for the animal. To find out more about an animal's status you can also go to the NatureServe and IUCN websites to check their rankings. Special Animals List Notes: 1) Formerly Bufo canorus; Frost, Grant, Faivovich, Bain, Haas, Haddad, De Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green & Wheeler (2006. The Amphibian Tree of Life. Bulletin of the American Museum of Natural History 297: 1-370) placed this species in the genus Anaxyrus (Tschudi, 1845). The standard common name remains Yosemite toad. 2) The USFWS published a final rule on April 29, 2014, to list the Yosemite toad as Threatened. The effective date for this rule is June 30, 2014.
Organization	Status Listing	Notes
NatureServe Global Ranking	G2G3	Imperiled - Vulnerable
NatureServe State Ranking	S2S3	Imperiled - Vulnerable
U.S. Endangered Species Act (ESA)	FT	Listed as Threatened 6/30/2014
California Endangered Species Act (CESA)	None
California Department of Fish and Wildlife	SSC	Species of Special Concern
Bureau of Land Management	None
USDA Forest Service	S	Sensitive
IUCN	EN	Endangered

Return to the Top