Habitat, dry wash, Deep Springs Valley, Inyo County (early June 2003)
One night in early July of 1999, this dry desert wash was full of water from recent rains and Great Basin Spadefoots were calling from the water and moving about on the valley floor.
Habitat, Inyo County
Grant County, Washington
One night while searching for spadefoot choruses to record, we discovered a spadefoot crossing a gravel road. After we picked it up and moved it to the sand for photographs, it began to slowly bury itself. It took about 5 minutes to completely bury itself, but that has been cut down to about a minute here.
Male spadefoots call at night from a shallow stagnant pool in central Washington.
Male spadefoots call at night from a shallow stagnant pool in central Washington.
Adults are 1.5 - 2.5 inches long from snout to vent (3.8 - 6.3 cm).
A small stout-bodied toad with short legs and warty skin.
There is a glandular bump between the eyes and a dark spot on each eyelid.
A glossy black spade shaped like a wedge is present on each hind foot.
Parotoid glands are not present.
Color and Pattern
Gray-green to olive above, with light stripes on the sides on the back,
and browinish or reddish spots at the tips of skin tubercles.
Eyes are gold with vertical pupils.
Tadpoles are dark brown - black above, golden below, with the eyes set in from the margin of the head, and grow up to 2.75 inches long (7 cm.)
Life History and Behavior
Nocturnal. Juveniles may feed during the day.
Almost completely terrestrial, entering water only to breed.
Spends 7 - 8 months of its life buried underground in deep burrows during the winter cold and in shallow burrows curing summer dry periods.
Spades on hind feet assist in digging burrows in the soil.
ammal burrows may be used also for refuge.
Great Basin Spadefoots are active on the surface at night after rains or during periods of agricultural irrigation.
Noxious skin secretions probaby repulse predators, and can cause burning and allergic-type reactions in humans.
There is little evidence of territorial behavior.
Unknown. Tinsley and Tocque (1995) estimated that females live about 13 years and males about 11 years in the wild.
Calls are made at night.
The call is a loud short 1-3 note duck-like snoring sound, which has been compared to the sound of a flock of ducks slowed down.
Diet and Feeding
Diet consists of a wide variety of invertebrates, much of which is ants.
Reproduction is aquatic.
Fertilization is external, with the male grasping the back of the female and releasing sperm as the female lays her eggs.
The reproductive cycle is similar to that of most North American Frogs and Toads. Mature adults come into breeding condition and 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 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.
Males probably become reproductively mature the first or second year after metamorphosis, and females in the second year.
Breeding takes place spring through summer (mostly April through July) depending on the location, in permanent and temporary pools, lakeshores, ponds, stock tanks, at the edges of agricultural fields, and irrigation ditches. East of the Sierra Nevada, where there is little rainfall or snowmelt to create temporary pools, breeding occurs in overflow pools of permanent streams and in springs.
Adults move from winter refuges to breeding sites when temperatures warm up, typically beginning in April, and it has been estimated they can travel as far as 5 km.
Rainfall can stimulate breeding, but it is not always necessary. Irrigation waters can stimulate breeding also.
Breeding does not necessarily occur at the same time each year at a location.
Breeding pools must remain filled for at least 40 days in order for larvae to successfully transform.
Females lay anywhere from 300 to 1000 eggs in small grape to plum-sized clusters of 20 - 40 eggs, which are attatched to floating sticks and underwater vegetation.
Eggs hatch after 2 - 4 days.
Tadpoles and Young
Tadpoles transform in about 47 days, ranging from 36 - 60 days.
Transformed juveniles move onto land temporarily before their tail has been fully absorbed.
Once metamorphosis is complete, they remain at the breeding site for a few days to several weeks before they travel away from the site.
Inhabits arid regions of sagebrush flats, bunch grass prairie, arid shrublands, and open forests with sandy soil.
In California this spadefoot is found in the Great Basin region east of the Sierras from the northern Owens Valley, north through the northeast corner of the state.
The species is found to the north of California, east of the Cascades mountains, through Oregon and Washington, into southern British Columbia, and east of California through southern Idaho and Wyoming, Utah, northeast Colorado, most of Nevada, and northwest Arizona.
Up to 9,200 ft. (2800 m).
Notes on Taxonomy
Before being assigned to the genus Spea, this spadefoot was known as Scaphiopus intermontana.
While Great Basin Spadefoots are extirpated in areas where agriculture and urbanization have destroyed their habitat, they have also colonized new areas where artificial water sources create new breeding sites.
Spadefoot Toads and Relatives
Great Basin Spadefoot
(Cope, 1883) - Proc. Acad. Nat. Sci. Philadelphia, Vol. 35, p. 15
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The following conservation status listings for this animal are taken from the October 2021 California "Special Animals List" and the October 2021 "State and Federally Listed Endangered and Threatened Animals of California" list, both of which are produced by multiple agencies and available here: https://www.wildlife.ca.gov/Data/CNDDB/Plants-and-Animals. You can check the link to see if there are more recent lists.
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 go to the NatureServe and IUCN websites to check their rankings.
This Spadefoot is not included on the Special Animals List, meaning there are no significant conservation concerns for it in California according to the California Department of Fish and Game.