Range in California: Green
Click the map for a guide
to the other subspecies.
Listen to this toad:
One short call
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Adult, northern Humboldt County |
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Adult, northern Humboldt County |
Adult, northern Humboldt County |
Juvenile, northern Humboldt County |
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Adult male, Thurston County, Washington, courtesy of Jim Lynch, Ft. Lewis Dept. of Fish and Wildlife |
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Juvenile, Deschutes County, Oregon |
Juvenile, Deschutes County, Oregon |
Nuptial pad on front foot of adult male, Thurston County, Washington. Specimen courtesy of Jim Lynch, Ft. Lewis Dept. of Fish and Wildlife |
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Adults in amplexus, Thurston County, Washington. Access to specimens courtesy of Jim Lynch, Ft. Lewis Dept. of Fish and Wildlife |
Tadpole, Deschutes County, Oregon |
Tadpole, Deschutes County, Oregon |
Habitat |
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Habitat, temporary pools on coastal plain, Humboldt County |
Habitat, Humboldt County coast
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More pictures of this toad and its habitat in the Nortwest are available on our Northwest Herps page.
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| Short Video |
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A toad gives a release call after he is picked up and gently grasped across the back. (It may sound like this toad is suffering, but it is not being harmed. This is a warning call, the same one he makes when another male toad comes into his territory or climbs onto his back and grabs him tightly with his legs.) |
An adult Boreal Toad hops around a coastal plain in Humboldt County.
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Description |
| Size |
| Adults grow to 2 - 5 inches from snout to vent ( 5.1 - 12.7 cm). |
| Appearance |
Large and robust with dry, warty skin. No cranial crests. Oval parotoid glands. Tarsal fold is well-developed. Pupils are horizontal. Coloring is greenish, tan, reddish brown, dusky gray, and yellow above with a light-colored stripe down the middle of the back. Warts are often rusty and set on dark blotches. There is much dark blotching above and below, becoming all dark at times. Males are usually less blotched than females and have smoother skin. Male and female throats are pale. Young have no dorsal stripe immediately after transformation.
More blotched below than B. b. halophilus. The head is also narrower with smaller eyes with more distance between the upper eyelids and the feet are also larger than B. b. halophilus. (Stebbins) |
| Voice (Listen) |
Male Boreal Toads do not have a pronounced vocal sac, but they do make a call during breeding aggregations. Their call has been described as a high-pitched plinking
sound, like the peeping of a chick, repeated seveal times. The sound of a group of males calling has been compared to the sound of a distant
flock of geese.
Calls are produced at night and during the day during the short breeding season. Males make their call primarily when they are in close
contact with other males. Rather than being advertisement calls made to attract females, these calls are generally considered encounter or aggressive calls, or release calls, which serve to maintain territory and spacing between males. The calls may also serve other purposes - a lone
male toad has been observed calling.1 It could also be possible that female toads are attracted to the sounds of male encounter calls, and can judge a male's condition by his call, similar to the function of an advertisement call.
Unreceptive females may also produce a release call when grasped on the back by a male. Males and females sometimes make a release call when grabbed across the back by a human hand. (See video above.) |
| Behavior |
Diurnal and nocturnal. Often diurnal after winter emergence, becoming nocturnal in the summer after breeding.
Toads are not territorial except when breeding. Amplexing males will kick away other males, and males may briefly fight other males at breeding sites.
For defense, this toad relies on
parotoid glands and warts which can secrete a poison that deters some predators. Other predators are immune to the poison, and will consume toads. Still other predators such as ravens have learned to avoid the poisons by eating only their viscera through the stomach.
Slow moving, often with a walking or crawling motion along with short hops.
Toads have been reported living at least 9 years. |
| Diet |
| Diet consists of a wide variety of invertebrates, including worms, spiders, moths, beetles, and ants. The prey is located by vision, then the toad lunges and quickly extends its large sticky tongue to catch the prey and bring it into the mouth to eat. Tadpoles consume algae and detritus, including the scavenged carrion of fish and other tadpoles. |
| Reproduction and Young |
Reproduction is aquatic. Fertilization is external. Adults are mature enough to breed when they are 4 - 6 years old. They breed shortly after they emerge from their hibernation sites and migrate to the breeding wetlands, using scent cues to find their way.
In some areas, breeding occurs after snowmelt when breeding ponds refill with water. Mating and egg-laying can occur any time from January to early July, depending on the elevation and winter snow levels.
Egg-laying takes place in still or barely moving waters of seasonal pools, ponds, streams, and small lakes.
Eggs are laid in long strings with double rows, averaging 5,200 eggs in a clutch. Fresh eggs contain some of the toads toxin to protect them from predation, but this poison decreases over time. Eggs hatch in 3 to 10 days, often longer in the colder waters of higher elevations.
Large schools of tadpoles often feed in shallow water. Tadpoles are dark brown, and grow to about 1 inch in length before metamorphosis. Tadpole development also depends on water temperature; tadpoles enter metamorphosis in 30 - 45 days, usually in late summer or early fall. In years of extreme winter weather, this might be only a few weeks before snow begins to accumulate again. When in the process of metamorphosis, many tadpoles are often seen in aggregations at the edge of a pond. Large numbers of newly-transformed toads are often seen hopping around the shores of breeding water. They may stay and spend the winter at the border of their natal wetland, or they may disperse to nearby sites away from the pond. |
| Range |
This subspecies is found across the northern tip of California. It continues to range east through Nevada, Utah, and Wyoming, and north through western Oregon and Washington, through British Columbia, all the way to southern Alaska. The species Bufo boreas is found in most of California except the deserts.
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| Habitat |
Inhabits a variety of habitats, including marshes, springs, creeks, small lakes, meadows, woodlands, forests, and desert riparian areas. In the spring and early summer, toads are often found at the edge of water, sometimes basking on rocks and logs. At other times of the year they are also found farther from the water where they spend much of their time in moist terrestrial habitats.Toads use rodent holes, rock chambers, and root system hollow as refuges from heat and cold.
Bufo boreas is found from sea level to over 11,800 ft. (3,600 m.) |
| Taxonomic Notes |
Two subspecies of Bufo boreas are recognized in California - Bufo boreas boreas, and Bufo boreas halophilus.
(Bufo nelsoni has also been treated as a subspecies of Bufo boreas: B. b. nelsoni, but this is controversial.)
Bufo boreas boreas has been renamed Anaxyrus boreas boreas, but this nomenclature is not yet standard. |
| Conservation Issues (Conservation Status) |
| Bufo boreas is becoming uncommon in many areas of the Pacific Northwest, the Rocky Mountains and other areas, probably due to environmental changes caused by habitat loss, especially loss of wetlands, and chemical contamination of wetlands. Toads are also slow-moving and are frequently run over by traffic as they cross roads at night during their breeding migrations, which could also contribute to their loss. |
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Taxonomy |
| Family |
Bufonidae |
True Toads |
| Genus |
Bufo |
True Toads |
| Species |
boreas |
Western Toad |
| Subspecies |
boreas |
Boreal Toad
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Original Description |
Bufo boreas Baird and Girard, 1852 - Proc. Acad. Nat. Sci. Philadelphia, Vol. 6, p. 174
Bufo boreas boreas Baird and Girard, 1852 Boreal Toad
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
Boreas - Greek meaning north wind or northern - which refers to the northern range
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Anaxyrus boreas boreas
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Related or Similar California Frogs |
Bufo boreas halophilus
Bufo californicus
Bufo woodhousii
Bufo canorus
Bufo exsul
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
AmphibiaWeb
1 Davidson, Carlos. Booklet to the CD Frog and Toad Calls of the Pacific Coast - Vanishing Voices. Cornell Laboratory of Ornithology, 1995
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.
Behler, John L., & F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.
Corkran, Charlotte & Chris Thoms. Amphibians of Oregon, Washington, and British Columbia. Lone Pine Publishing, 1996.
Jones, Lawrence L. C. , William P. Leonard, Deanna H. Olson, editors. Amphibians of the Pacific Northwest. Seattle Audubon Society, 2005.
Leonard et. al. Amphibians of Washington and Oregon. Seattle Audubon Society, 1993.
Nussbaum, R. A., E. D. Brodie Jr., and R. M. Storm. Amphibians and Reptiles of the Pacific Northwest. Moscow, Idaho: University Press of Idaho, 1983.
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.
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The following status listings come from the Special Animals List which is published several times each year by the California Department of Fish and Game.
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) |
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| California Endangered Species Act (CESA) |
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| California Department of Fish and Game |
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| Bureau of Land Management |
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| USDA Forest Service |
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| Natureserve Global Conservation Status Ranks |
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World Conservation Union - IUCN Red List
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