There does not appear to be one 'smoking gun'; numerous environmental factors are probably responsible for the declines and deformities.
Multiple limbs, missing limbs, and facial abnormalities are the main developmental malformations seen.
Scientists have documented four major 'hot spots' for amphibian declines: western North America, Central America, northeast Australia, and Puerto Rico.
Amphibians are good indicators of significant environmental changes. Amphibians, unlike people, breathe at least partly through their skin, which is constantly exposed to everything in their environment.
The worldwide pattern of amphibian declines includes both loss of populations from parts of species' ranges -- the pattern seen in Australia and Central American tropics with stream frogs -- and declines of entire species, such as ranid frogs in Califo
There are about 230 species of amphibians, including about 190 species of salamanders and 90 species of frogs and toads, that can be found in the continental United States.
In response to indications of worldwide declines in amphibian populations, the President and Congress directed Interior Department agencies to initiate a national program of amphibian monitoring, research, and conservation.
Learn more:Amphibian Research and Monitoring Initiative