Worldwide Decline of Amphibians
The worldwide decline of amphibians indicates that important changes are occurring in the natural world. More than 520 scientists from over 60 countries contributed to a three-year study of the distribution and status of amphibians. The sobering results of their labor are summarized in the Global Amphibian Assessment, which is online at www.globalamphibians.org. Of the 5,743 species of amphibians that are known to science about one third are threatened. At least thirty-four species are known to be extinct and another 113 species have not been found in recent years and are probably extinct. Forty-three percent of the known amphibian populations are declining while less than 1 percent are increasing in numbers, which means that the number of threatened species will increase.
The largest numbers of threatened amphibian species occur in neotropical countries such as Columbia (208), Mexico (191) and Ecuador (163), while the highest levels of threat occur in the Caribbean where more than 80 percent of the amphibians are threatened in Dominican Republic, Cuba, Jamaica and Haiti. Habitat loss is the greatest threat to amphibians, and a newly-recognized fungal disease is seriously affecting an increasing number of species.
Over geological time amphibian species have been more resistant to extinction than other groups such as birds and mammals (all species eventually go extinct) yet 32 percent of amphibian species are now threatened while 12 percent of all bird species and 23 percent of all mammal species are threatened. The decline of amphibians in recent years is unprecedented in the context of the last several million years.
We spoke with Simon Stuart about the Global Amphibian Assessment.