Spea multiplicata has no boss between the eyes, and the eyelids are wider than the space between them. The dorsal color is uniformly brown or dark gray with small dark spots or blotches and red-tipped tubercles scattered over the dorsum, and no dorsolateral stripes are present. A short wedge-shaped spade is present on each hind foot. The iris is slightly variegated and appears pale copper colored. Male vocal sacs appear as a dark, heavily pigmented area on the throat (Conant and Collins 1991).
The body of the tadpole is broadest just behind the eyes, tapering gradually towards the bottom of the tadpole and tapering sharply towards the top. It has a short snout, and a tail that is about 1 1/3 - 1 1/4 times the head-body length that has its greatest width near the midpoint. The dorsal fin originates posteriorly on the body. The eyes are close together and well up on the head, and the anus is medial, emerging in the base of the ventral fin. The spiracle is low on the left side, belove the lateral axis of the body (Stebbins 1962).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Mexico, United States
U.S. state distribution from AmphibiaWeb's database: Arizona, Colorado, New Mexico, Oklahoma, Texas, Utah
S. multiplicata ranges from western Oklahoma to Arizona (Arizona, New Mexico, Utah, Colorado, and Texas) and far south into Mexico (Conant and Collins 1991).
S. multiplicata can be found in various habitats, including grasslands, sagebrush flats, semi-arid shrublands, river valleys, and agricultural lands. It is sometimes found on roads following summer thundershowers (Degenhardt et al. 1996).
Life History, Abundance, Activity, and Special Behaviors
This species is largely nocturnal and secretive, and during the summer rainy season can be found hidden under surface objects. It usually occupies an underground burrow that it digs in the soft earth with its hind feet, like other spadefoots in New Mexico. The hind feet are equipped with keratinized, sharp-edged spades. It is often seen on roadways during the night, in search of breeding sites or prey. S. multiplicata may secrete a musty skin toxin when it is molested. The toxin smells like raw peanuts and can irritate the sensitive membranes of the eyes and nose of those who rub their face after handling a spadefoot (Degenhardt et al. 1996).
S. multiplicata breeding, like that of other spadefoots, is closely associated with the summer monsoon rains that fill playa lakes and cause the rapid formation of pools in low-lying areas. The low frequency sound and vibration of rainfall or thunder are the primary cues for emergence. Average breeding period duration is only about 1.6 days. Males usually call while they are floating on the surface of the water. Eggs are fertilized by the male as they are laid during amplexus. There is a high level of variation in clutch size within breeding aggregations, but an adult female lays about 1,070 eggs on average. Eggs are deposited in cylindrical masses that are attached to submerged aquatic vegetation or debris. They hatch in as little as 42-48 hours. The tadpoles metamorphosize in about three weeks, and toadlets emerge from the drying pond and disperse (Degenhardt et al. 1996).
S. multiplicata is a generalized arthropod predator that concentrates on ground dwelling species, as do most spadefoots. Beetles, orthopterans, ants, spiders, and termites comprise over 90% of their total diet, with no major differences in diet by sex or season. Arthropods with well known chemical defenses, such as blister beetles, velvet ants, stink bugs, and millipedes, are usually avoided by S. multiplicata, but it will occasionally feed on centipedes and scorpions. Studies have shown that S. multiplicata may require seven feedings before it has accumulated the fat reserves required to survive for 12 months (Degenhardt et al. 1996).
The call is a vibrant, metallic trill that sounds like running a fingernail along the stiff teeth of a comb. Each of these trills is about 0.75 - 1.5 seconds long (Conant and Collins 1991).
Similar species: S. multiplicata can be easily mistaken for Spea bombifrons. Newly metamorphosed toadlets which have been in preservative for long periods of time are difficult to distinguish. S. multiplicata lacks a frontal boss, unlike adult S. bombifrons, but these two species frequently hybridize making this characteristic unreliable at times (Simovich 1994). S. multiplicata can be distinguished from Scaphiopus couchii by coloration: brown or dark grey with red-tipped tubercles in S. multiplicata, vs. greenish-yellow dorsum with dark mottling in Scaphiopus couchii (Degenhardt et al. 1996).
Brown, H. A. (1976). ''The status of California and Arizona populations of the Western Spadefoot Toads (genus Scaphiopus).'' Los Angeles County Museum of Natural History, Contributions in Science, 286, 1-15.
Conant, R. and Collins, J. T. (1991). A Field Guide to Reptiles and Amphibians: Eastern/Central North America. Houghton Mifflin, Boston.
Degenhardt, W.G., Painter, C.W., and Price, A.H. (1996). Amphibians and Reptiles of New Mexico. University of New Mexico Press, Albuquerque.
Sattler, P.W. (1980). ''Genetic relationships among selected species of North American Scaphiopus.'' Copeia, 1980(4), 605-610.
Simovich, M. A. (1994). ''The dynamics of a spadefoot toad (Spea multiplicata and S. bombifrons) hybridization system.'' Herpetology of North American Deserts. P. R. Brown and J. W. Wright, eds., Special Publication No. 5, Southwestern Herpetologists Society, Los Angeles.
Smith, H. M. (1978). A Guide to Field Identification: Amphibians of North America. Golden Press, New York.
Stebbins, R. C. (1962). Amphibians of Western North America. University of California Press, Berkeley.
Tanner, W. W. (1989). ''Status of Spea stagnalis Cope (1875), Spea intermontanus Cope (1889), and a systematic review of Spea hammondii Baird (1839) (Amphibia: Anura).'' Great Basin Naturalist, 49, 503-510.
Written by Sunny Shah (sunnys AT uclink.berkeley.edu), UC Berkeley
First submitted 2001-12-13
Edited by Kellie Whittaker (2009-04-07)
Species Account Citation: AmphibiaWeb 2009 Spea multiplicata: Mexican Spadefoot <http://amphibiaweb.org/species/5281> University of California, Berkeley, CA, USA. Accessed Oct 23, 2016.
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Citation: AmphibiaWeb. 2016. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 23 Oct 2016.
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