New Mexico spadefoot toad

New Mexico spadefoot toad
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Scaphiopodidae
Genus:	Spea
Species:	S. multiplicata
Binomial name
Spea multiplicata (Cope, 1863)
Synonyms
Scaphiopus multiplicatus Taylor , 1952

The New Mexico spadefoot toad (Spea multiplicata) is a species of American spadefoot toad found in the southwestern United States and Mexico. Like other species of spadefoot toad, they get their name from a distinctive spade-like projections on their hind legs, which enable them to dig in sandy soils. Spea multiplicata can be identified by its wedge-shaped spade. Some sources also refer to the species as the Mexican spadefoot toad, desert spadefoot toad or southern spadefoot toad.

Description

The New Mexico spadefoot toad has a length of 1.5 to 2.5 inches (3.8 to 6.4 cm) with a round body and relatively short legs. They weigh between 1.7 and 3.5 ounces (48 and 99 g).^[2] They are green, to grey, to brown, usually reflecting the soil color of their native habitat, often with black and orange colored speckling on their back, and a white underside. They have large eyes, with vertical pupils.

Behavior

Like all species of spadefoot toad, the New Mexico spadefoot toad is

The New Mexico spadefoot toad has been the subject of research related to the possible effects of climate change (specifically changes in rainfall and temperature) on reproduction and development. The impact of water loss at different tadpole stages was studied in the lab in two sets of experiments.[7] Both experiments studied how water loss affected tadpole development, corticosterone levels, spleen size and cellularity, and overall body size. Overall, compared to control tadpoles who experienced no water loss, tadpole groups that experienced steady water loss had a faster rate of metamorphosis, but no consistent differences in corticosterone levels, spleen size or cellularity, or overall body size. This study concluded that while water loss will cause increased rates of development in spadefoot tadpoles, this does not necessarily result in changes in body size in adult spadefoot.

Another potential effect of climate change could be on the spadefoot toad's calling behavior, used by males to attract mates, which is temperature dependent.^[8] Researchers examined the relationship between the calling of spadefoot toads and temperature by compiling climate records of temperature and precipitation over a 22-year period.  Interestingly, although air temperatures increased over time in the spadefoots’ habitat, the water temperature of their breeding ponds has mostly declined, which can be explained by fluctuations in rainfall temperatures. Generally, faster and higher calls by males result in greater reproductive success. Once researchers corrected call rates for temperature, spadefoot call duration decreased while pulse and call rates increased over time. These findings show that climate change does not always have a direct effect on temperature-dependent traits. Instead, it can cause changes in species’ microenvironments that can have a greater impact on animal traits.

Trivia

• The New Mexico spadefoot toad was designated as the official State Amphibian of New Mexico in 2003.

References