iPhone App
Electronic Field Guide to the
Reptiles and Amphibians of
Southern California
Available Now at the
iTunes App Store. |
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| Adult, Riverside County |
Adult, Riverside County |
Adult, Riverside County |
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| Adult, Riverside County |
Adult, Riverside County |
Adult, Imperial County
© Patrick Briggs |
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| Cranial crests converge at the front. |
Comparison of Anaxyrus cognatus on right and Anaxyrus woodhousii on left.
The cranial crests of A. cognatus point inward at the front, often coming together.
The parotoid glands of A. woodhousii are more elongated than on A. cognatus. |
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| Breeding Adults |
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| Calling adult male, Riverside County |
Calling adult male, Riverside County |
Calling males, Riverside County |
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Male and female in amplexus,
Riverside County |
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| Great Plains Toads From Outside California |
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Adult, Cochise County, Arizona |
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| Adult, Cochise County, Arizona |
Adult, New Mexico |
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| Habitat |
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| Breeding habitat, edge of irrigated field, Riverside County |
Breeding habitat, edge of irrigated field, Riverside County |
Habitat, agricultural irrigation pond, Riverside County |
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Irrigation canal habitat,
Imperial County
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| Short Video |
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Ttwo male toads calling at night in Riverside County.
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Description |
Size |
| Adults are 1 4/5 - 4 1/5 inches from snout to vent ( 4.6 - 11.4 cm). |
| Appearance |
A large and robust toad with dry, warty skin. Cranial crests form a boss on snout and separate widely toward the rear of the head. A sharp tubercle on each hind foot. Light brown, gray, or olive above with large, symmetrical olive, or green blotches with light borders. May have a thin stripe along the middle of the back. Pale whitish below usually with no spots. Young have many small red tubercles and a v-shaped crest.
Parotoid glands are elongated. Pupils are horizontal. |
| Voice (Listen) |
| The call of this toad is an explosive jackhammer-like metallic trill lasting from 5 seconds to almost a minute. It can be almost deafening when heard from a close distance. Calls are made at night. |
| Behavior |
Adults are nocturnal, juveniles are diurnal. Sometimes seen out during daylight on cloudy, rainy days. A good burrower, this toad remains underground in the daytime burrowed into loose soil. Remains underground during periods of prolonged cold and heat - which can be 63 - 77 percent of the year.
A typical toad: slow moving, often using a walking or crawling motion along with short hops. For defense, like most toads, this toad relies on parotoid glands and warts which can secrete a poison that deters some predators.
Long-lived, from 10 - possibly 20 years. |
| Diet |
| This toad's diet consists of a variety of invertebrates, including ants, flies, centipedes, mites, and cutworms. 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 and Young |
Reproduction is aquatic. Fertilization is external. Throughout most of their range, they emerge from burrows after heavy spring rains and move to breeding wetlands, generally from March to September. (In the irrigated agricultural lands in the desert where this toad has increased its range in California, breeding might be stimulated by another factor such as irrigation or temperature change, since little rain falls in the area.) Reproduction can take place throughout the season and females may lay eggs multiple times in a single year.
Adults are reproductively mature at 2 - 5 years of age. (2 years in Arizona, and probably the same in California.)
Breeding and egg-laying takes place in temporary pools, slow streams, irrigation ditches, holding ponds and flooded fields. Eggs are laid in either single or double strings and attached to debris in clear, shallow, water with little current. According to one expert (Krupa, 1994) egg laying usually begins at dawn and finishes by noon. At one location study, females laid from 1,342 - 45,054 eggs, an average of 11,074. Eggs generally hatch in 2 - 7 days.
Tadpols graze on submerged rocks or plants feeding on plant material and decomposing invertebrate remains. Tadpoles begin to metamorphose anywhere from 17 - 45 days after hatching, depending on water temperature and evaporation rates. Tadpole survival rate varies from year to year, with few surviving during a bad year.
Newly metamorphed toads stay near their birth pond for about a month or less if it dries up. They then move into agricultural fields where they can burrow into the soil, sometimes forming large aggregations. |
| Range |
In California, Great Plains Toads are found in the Imperial Valley in Imperial and Riverside Counties, and along the Colorado River in Imperial, Riverside, and San Bernardino Counties. They most likely spread up the Imperial Valley from the Colorado River with the development of agriculture.
The species ranges throughout the plains states east of the Rockies east into the eastern edges of Minnesota, Iowa, and Missouri, into western Texas, New Mexico, and Arizona, into parts of Utah and Nevada, and into Canada and Mexico. |
| Habitat |
This toad inhabits creosote bush and mesquite deserts and desert scrub, prairie grasslands, sandhills, sagebrush plains, and agricultural regions, in asociation with temporary ponds, wetlands, and irrigation ponds and ditches. Great Plains Toads are more tolerant of dry conditions than most toad species.
From below sea level to 8,000 ft. (2,440 m.) |
| Taxonomic Notes |
| 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. |
| Conservation Issues (Conservation Status) |
| None |
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Taxonomy |
| Family |
Bufonidae |
True Toads |
| Genus |
Anaxyrus |
North American Toads |
| Species |
cognatus |
Great Plains Toad
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Original Description |
Bufo cognatus Say, 1823 - in James, Long's Exp. Rocky Mts., Vol. 2, p. 190
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Bufo - toad
Anaxyrus - Greek - A king or chief
cognatus - Latin - related by birth
Taken in part from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Bufo cognatus
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Related or Similar California Frogs |
Anaxyrus boreas halophilus
Anaxyrus woodhousii
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
AmphibiaWeb
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.
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.
Wright, Anna. Handbook of Frogs and Toads of the United States and Canada. Cornell University Press, 1949.
Davidson, Carlos. Booklet to the CD Frog and Toad Calls of the Pacific Coast - Vanishing Voices. Cornell Laboratory of Ornithology, 1995.
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| Conservation Status |
The following status listings come from the Special Animals List which is published by the California Department of Fish and Wildlife.
This toad is not on the Special Animals List. There are no significant conservation concerns for it in California.
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Organization
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Status Listing
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| U.S. Endangered Species Act (ESA) |
None |
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| California Endangered Species Act (CESA) |
None |
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| California Department of Fish and Wildlife |
None |
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| Bureau of Land Management |
None |
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| USDA Forest Service |
None |
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| Natureserve Global Conservation Status Ranks |
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World Conservation Union - IUCN Red List
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