Frog, Toad Population Declining across US: Study

Frogs and toads are fast disappearing across the U.S., says a new study by the U.S. Geological Survey. Researchers estimate that at the current rate of extinction, most amphibians will vanish from half of their habitats in about two decades.

Additionally, even relatively stable species of some amphibians are now vanishing. This declining population has been noted from Louisiana and Florida to Sierras and the Rockies.

"Amphibians have been a constant presence in our planet's ponds, streams, lakes and rivers for 350 million years or so, surviving countless changes that caused many other groups of animals to go extinct. This is why the findings of this study are so noteworthy; they demonstrate that the pressures amphibians now face exceed the ability of many of these survivors to cope," said Suzette Kimball, Director, USGS.

The population of amphibians is disappearing at a rate of 3.7 percent every year. If this rate continues, most of the amphibian species will vanish from their current habitat in another 20 years.

The highly-threatened species, those included in the "Red-List", will disappear from half of their habitats in the next six years.

Michael Adams, ecologist with the USGS and lead author of the study, said that the rate of decline in the amphibian population is surprising. "We knew there was a big problem with amphibians, but these numbers are both surprising and of significant concern," Adams said.

For the study, researchers observed the amphibian population in lakes and ponds for about nine years. The team hasn't identified the reasons behind this decline.

Many creatures are facing a decrease in population due to habitat loss. For amphibians, habitat loss, diseases, invasive species and contaminants may be behind the drastic reduction of population.

"The declines of amphibians in these protected areas are particularly worrisome because they suggest that some stressors - such as diseases, contaminants and drought - transcend landscapes," Adams said in a news release. "The fact that amphibian declines are occurring in our most protected areas adds weight to the hypothesis that this is a global phenomenon with implications for managers of all kinds of landscapes, even protected ones."