About 8,900 species of amphibians (frogs, salamanders, and caecilians) are found world-wide. Of these, 116 species are frogs that inhabit the United States. The greatest diversity of amphibians occurs in the Southeastern United States. Frogs can be found in both aquatic and terrestrial habitats, from deep water to tall trees. They are adapted to local environments in coloration, body structure, and behavior.

Of the more than 800 species of salamanders found worldwide, more than 230 live in North America. Over 40 percent of these are considered to be at risk.