spade on each foot to dig a burrow, where it spends long periods during cold and dry weather. The toad is able to absorb water from the surrounding soil; even as the soil becomes increasingly dry in spring and early summer months, increased concentrations of urea in the toad's body allow it to continue to suck water out of the soil through osmosis. When the summer rains arrive the Great Basin spadefoot emerges from its burrow. Morphs and adult Great Basin spadefoots normally venture from their burrows at night, when it is rainy or the night air is humid enough for dew to collect. Captive spadefoots have been observed to dig shallow burrows in moist soil, then dig deeper (2 to 3 feet [0.7–1.2 m]) as soil dries at the surface. Spadefoots have been found 15 feet (4.6 m) underground in natural conditions. An individual spadefoot digs and occupies only one burrow, which it usually returns to after foraging or mating. Spadefoots do not use shrubs or other vegetation for cover while foraging. Spadefoots accumulate fat rapidly in summer. They are dormant in fall and winter, with dormancy apparently triggered by photoperiod. Spring emergence may be triggered by increased moisture in the burrow. Spadefoots extend their dormancy period during drought, and can apparently remain dormant or mostly dormant for long periods of time. Fat reserves are metabolized slowly during dormancy, and females may reabsorb their eggs if spring rains do not occur. References Further reading Maxymiv, N. (2006). "Anuran Reproduction- Two Major Systems". Tree of Life Web Project. Retrieved 2009-10-08. Morey, S.R. "Spea intermontana- Lannoo Account". AmphibiaWeb. Retrieved 2009-10-8. Pough et al. (2004). Herpetology (3rd ed.). Upper Saddle River: Pearson Education, Inc. Stebbins, Robert C. (2003). Western Reptiles and Amphibians (3rd ed.). New York: Houghton Mifflin Company. Zack, R.S., and Johnson, D.G. (2008). "Feeding by the Great Basin Spadefoot Toad." Western North American Naturalist 68(2), 241–244. "Zion National Park- Amphibians". National Park Service. Retrieved 2009-10-07. Whorely, J. (1999-02-17). "Spea intermontana- AmphibiaWeb Account". AmphibiaWeb. Retrieved 2009-10-08. External links IUCN.org: Great Basin spadefoot range−map Spea Toad, Great Basin Fauna of the Great Basin Amphibians described in 1883 Taxonomy articles created by Polbot