The first-ever estimate of how fast frogs, toads and salamanders in the United States are disappearing from their habitats reveals they are vanishing at an alarming and rapid rate. The study, conducted over the last decade by U.S. Geological Survey scientists and collaborators, includes contributions by a Penn State wildlife population ecologist.
Around the world, amphibian populations are in decline, and scientists have not been able to figure out why. Now a study of leopard frogs in Pennsylvania has identified a possible culprit, and the ramifications are troubling, according to a Penn State ecologist. Research conducted primarily at Penn State's Russell E. Larson Agricultural Research Center at Rock Springs in the summer of 2007 -- described in a recently published article in the journal Nature -- suggests that chemical pollution can increase often-deadly trematode (parasitic flatworm) infections in a declining amphibian species.
Carl Linneaus, the father of modern taxonomy, didn't think highly of toads. "These foul and loathsome animals are abhorrent because of their cold body, pale color, filthy skin, fierce aspect, calculating eye, offensive smell, harsh voice, squalid habitation, and terrible venom," he wrote of toads and other amphibians in 1758, "and so their Creator has not exerted his powers to make many of them."
When the continents were moving together to form the giant landmass Pangaea, over 250 million years ago, more than 500 animal families lived in the ocean. There were rugose and tabulate corals, trilobites, bryozoans, and brachiopods, as well as some fish and amphibians. At the end of the Permian period 95 percent of these marine species were extinct.
It's mid August here in central Pennsylvania, and the land is gripped by drought. But two miles north of Penn State's main campus, the forest is a tangle of verdant health. This is where biology graduate student Matt Laposata spends much of his summer hours. Today he's inspecting temporary homes for Jefferson salamanders.