Where have amphibian declines been noted?
Scientists have documented four major 'hot spots' for amphibian declines: western North America, Central America, northeast Australia, and Puerto Rico. Researchers believe that all of these declines , most in seemingly pristine areas, have occurred since around 1980. Other areas of the world may also be affected by such declines, but until research is conducted in other continents and regions, the extent of possible declines is unknown.
In the United States and its territories, major declines of frog populations have been noted in California, the Rocky Mountains, Puerto Rico, and in areas of the Southwest. Some of these declines have occurred in some of our Nation's largest parks and wilderness areas, where we would expect wildlife to be most protected. Northern leopard frogs, for example, have disappeared or become rare over much of their known range in western North America. Boreal toads have undergone an 80 percent decline in the southern Rocky Mountains. In parts of the Sierra Nevada and adjacent foothills, several amphibian species, including mountain and foothill yellow-legged frogs and red-legged frogs, have declined over areas of 100 square miles or so. And in Puerto Rico, almost two-thirds of the native amphibians are declining; some species have not been found for several years.
Learn more: The State of Amphibians in the United States