A recent U.S. Geological Survey report confirmed that the nation's amphibians, including frogs, toads and salamanders, are disappearing "at an alarming and rapid rate." A biologist at the University of North Carolina at Chapel Hill has found that North Carolina's Southern Cricket Frog populations mirror this disturbing national trend.
"It's a steady flow of bad news for amphibians," said Jonathan Perry Micancin [mih-CAN-sin], a visiting lecturer and recent Ph.D. graduate in UNC's Biology Department. The cold-blooded animals require wetlands to breed and surrounding forests for food and shelter. They play an important role in nature's food chain, Micancin said, eating insects and providing food for larger animals, including snakes and birds.
For his dissertation and ongoing research, Micancin studied two different but co-occurring species in North Carolina, the Northern Cricket Frog (Acris crepitans) and the Southern Cricket Frog (Acris gryllus). The northern species occupies the Piedmont as far west as the Appalachian foothills, while the southern species is found in the state's Coastal Plain, between the Piedmont and the coast. The two overlap, a condition biologists call "sympatry," in the upper Coastal Plain.
Micancin and his students searched for the tiny frogs they are no more than 1 inches long in wetlands throughout most of the state, from Crowders Mountain, near Charlotte, to Carolina Beach, south of Wilmington, to Merchants Millpond, in Gates County, and Lake Waccamaw in Columbus County. He used their distinctive calls as identifiers.
"The two species are hard to identify visually because they are so small and well-camouflaged." said Micancin. "Fortunately, their calls are very different: Southern Cricket Frogs 'chirp' and Northern Cricket Frogs 'rattle.' " Using statistical analysis, he confirmed that it is "easier to identify them by sound than by sight."
Micancin and colleagues looked
|Contact: Kathy Neal|
University of North Carolina at Chapel Hill