Range in California: Red
Listen to this spadefoot:
A short example
More sounds of
Scaphiopus hammondii
Watch a video of this spadefoot at naturebytesvideo.com
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Adult, San Joaquin County |
Adult, San Joaquin County |
Adult, San Joaquin County |
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Spade on rear foot,
San Diego County |
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Juvenile, San Luis Obispo County
© Andrew Harmer |
Egg masses found attached to spike rush at or just below the water surface at sites with depths of 18-24 inches. Large (~0.5 acre) ephemeral constructed livestock watering basin in Monterey County. Site is near arroyo with abundant loose sandy substrate. © Pete Trenham |
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Habitat |
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Shallow breeding pool with tadpoles, San Diego County |
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Habitat, Glenn County |
Breeding pool, Butte County |
Breeding habitat damaged by illegal off-road vehicle activity, Butte County |
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Breeding pool, San Luis Obispo County, © Andrew Harmer |
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Description |
| Size |
| Adults are 1.5 - 2.5 inches long from snout to vent (3.7 - 6.2 cm). |
| Appearance |
A stout-bodied toad, greenish, brown, or gray above, often with 4 irregular light stripes and dark blotches on the back,
and reddish spots at tips of skin tubercles. Unmarked and whitish below. Eyes are pale gold with vertical pupils. There is no
bump between the eyes. A glossy black spade shaped like a wedge or teardrop is present on each hind foot. The spades assist in digging soil. No parotoid glands. |
| Voice (Listen) |
| The call of the Western Spadefoot is a short loud trill, like a quick snore, lasting less than one second. Males call at night while floating on the water, often in large aggregations. |
| Behavior |
Almost completely terrestrial, entering water only to breed. Rarely seen -spends most of its life buried underground, active at night and only for a short period. Most often active on the surface some time between October to May depending on rainfall, but occasionally emerges during rains at other times of the year. Heavy rainfall triggers emergence and the quick assembly of breeding congregations. This spadefoot is able to inhabit hot dry environments by burrowing underground, which is made possible by the hardened spades on the hind feet.
Skin secretions smell like peanuts, and sometimes cause runny nose and watery eyes in humans. |
| Diet |
| Eats a variety of invertebrates. Probably consumes enough in several weeks to survive the long period of underground dormancy. Typical of most frogs, the prey is located by vision, then a large sticky tongue is used to catch the prey and bring it into the mouth to eat. |
| Reproduction |
Generally, breeding occurs from January to May, most often during spring rains, but this spadefoot is an opportunistic breeder, physiologically capable of breeding at any time if conditions are favorable. (Ervin & Cass, 2007)
Breeding occurs after heavy rainfall and the formation of temporary shallow rain pools. These temporary pools must last for at least 3 weeks to be usable for breeding. The loud calls of the first male to enter the pond quickly attract other males and females to the breeding pool. These pools do not always occur in the same place each year, so the adults may be scattered at a distance from the pool. During dry years, breeding pools may not form at all and spawning will not take place. When it does occur, spawning might take place on only one or two nights a year at a particular location.
Fertilization is external. Small, cylindrical irregular groups of eggs are laid and attached to underwater vegetation or detritus. Eggs hatch very quickly, anywhere from a little over half a day to 6 days later. Tadpoles transform quickly in 3 - 11 weeks, depending on temperature and food availability. This accellerated development of eggs and larvae due to the temporary nature of its breeding pools and activity period is typical of spadefoots. |
| Range |
| Endemic to California and northern Baja California. Ranges from the north end of California's great central valley near Redding, south, east of the Sierras and the deserts, into northwest Baja California. From near sea level up to 4,000 ft. (1200 m). |
| Habitat |
| Prefers open areas with sandy or gravelly soils, in a variety of habitats including mixed woodlands, grasslands, chaparral, sandy washes, lowlands, river floodplains, alluvial fans, playas, alkali flats, foothills, and mountains. Rainpools which do not contain bullfrogs, fish, or crayfish are necessary for breeding. |
| Taxonomic Notes |
| For many years S. hammondii was grouped with spadefoots from Arizona through New Mexico into western Texas and Oklahoma, with the California subspecies called Scaphiopus hammondii hammondii. |
| Conservation Issues (Conservation Status) |
| This spadefoot has lost an extensive amount of habitat in the central valley due to urban and agricultural development of land that formerly supported the formation of temporary rain pools. It is estimated to be gone from almost 80 percent of its former habitat along the south coast. Mosquitofish introduced into vernal pools may also threaten some populations. |
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Taxonomy |
| Family |
Pelobatidae |
Spadefoot Toads and Relatives |
| Genus |
Spea |
Western Spadefoots |
| Species |
hammondii |
Western Spadefoot
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Original Description |
(Baird, 1859) - Rep. Pacif. R.R. Survey, Vol. 10, Williamson's Route, Pt. 4, No. 4, p. 12, pl. 28, fig. 2 ["1857" 1859]
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Spea - speos - Greek for cave, cavern
hammondii - honors Hammond, John F.
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Scaphiopus hammondii hammondii - Western Spadefoot
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Related or Similar California Frogs |
Scaphiopus couchii
Spea intermontana
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
AmphibiaWeb
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.
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.
Storer, Tracy I. Amphibia of California, University of California Press, 1925.
Davidson, Carlos. Booklet to the CD Frog and Toad Calls of the Pacific Coast - Vanishing Voices. Cornell Laboratory of Ornithology, 1995.
Ervin, Edward L. and Timothy L. Cass. Herpetological Review 38 (2) 2007.
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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.
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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 Game |
DFG:SSC |
California Species of Special Concern |
| Bureau of Land Management |
BLM:S |
Sensitive |
| USDA Forest Service |
None |
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| Natureserve Global Conservation Status Ranks |
G3 S3 |
Vulnerable |
World Conservation Union - IUCN Red List
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IUCN:NT |
Near Threatened |
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