Frontlines | Open Wide and Say "Ribbit"
Some frogs may be croaking before they go 'a courting. Scientists working with students in Acadia National Park in Maine have observed plenty of dead tadpoles among the preserve's vast wetlands. But it's impossible to know whether the death rates are unusually high--the park's 47,633 acres span two islands and a peninsula--or whether some species are dying at higher rates than others, says Aram Calhoun, assistant professor of wetlands ecology, University of Maine. So researchers are screening Acadia frogs and those from parks around the nation for health problems.
Frog deaths are reportedly on the rise worldwide. Scientists have linked frequent deformities to runoff contaminated with herbicides and pesticides,1 but Calhoun and David Green, a pathologist for the National Wildlife Health Center in Madison, Wis., say it's too soon to link the Acadia deaths to chemicals or anything else, such as impaired or lowered immune function.
The Acadia research is part of the nationwide Amphibian Research and Monitoring Initiative, which is examining the health status of native species under pressure, introduced species, and sentinel species whose numbers are not in decline. Besides screening the frogs, scientists are examining the Acadia vegetation and analyzing water chemistry.