Plains Spadefoot Toad

Taxobox
name = Plains Spadefoot Toad
status = LC | status_system = IUCN3.1
regnum = Animalia
phylum = Chordata
classis = Amphibia
ordo = Anura
subordo = Mesobatrachia
familia = Scaphiopodidae
genus = "Spea"
species = "S. bombifrons"
binomial = "Spea bombifrons"
binomial_authority = Cope, 1863

The Plains Spadefoot Toad ("Spea bombifrons") is a species of spadefoot toad which ranges from southwestern Canada, throughout the Great Plains of the western United States, and into northern Mexico. Like other species of spadefoot toad, they get their name from a spade-like projection on their hind legs which allows them to dig into sandy soils.

Description

The Plains Spadefoot Toad generally grows from 1.5 to 2.5 inches in length, has a round body, with relatively short legs. They vary in color from greys to browns, usually reflecting the color of the soil in their native habitat, with a white underside. Sometimes they have light striping on their back.

Behavior

Plains Spadefoot Toads are nocturnal, and secretive. They spend most of the dryer seasons buried in the soil in estivation, typically only emerging during spring and fall rains. Breeding takes place in temporary pools of water left by rainfall, which requires the tadpoles to metamorphosize quickly, before the water dries up. Eggs, laid in clutches numbering from 10-250, often hatch within 48 hours of being laid, and the larvae can change into toadlets in as little as two weeks. The tadpoles exhibit phenotypic plasticity, with some tadpoles changing from an omnivorous morphology into a cannibalistic carnivorous morph with oversized jaw muscles and a pronged beak. A recent study has shown that in some cases female spadefoot toads will choose to mate with Spea multiplicata rather than with males of their own species, if the resulting hybrid tadpole would have higher chances of survival. [cite web
url = http://news.bbc.co.uk/2/hi/science/nature/7085924.stm
title = Toads are 'open-minded' about sex
date = 2007-11-09
accessdate = 2007-11-09]

References

* [http://www.zo.utexas.edu/research/txherps/frogs/spea.bombifrons.html Herps of Texas: "Spea bombifrons"]
* [http://collections.ic.gc.ca/amphibians/taxa/species/spea_bombifrons.html Canada's Amphibians: "Spea bombifrons"]