Frog real estate: more than location.
Peter B. Pearman of Evergreen State College in Olympia, Wash., points out that species often dwindle when a habitat is chopped into small, separated patches. Bears and certain woodland birds shrink in number. Frogs suffer, too.
Pearman and David Marsh of the University of California, Davis warn that proposed fixes for tattered habitats may help one species but not another. They report their findings in the December 1997 Conservation Biology.
Marsh studied two species of Eleutherodactylus frogs in snippets of forest in Ecuador. He also checked frogs in an intact, 500-acre forest. "We were looking for sledgehammer effects, and we seem to have found them," says Pearman.
The numbers of one species seemed to be affected primarily by shrinking fragment size, whereas those of the other responded more to distance between fragments. Pearman warns that protecting corridors of forest that connect fragments, often proposed as a remedy for butchered habitat, would not help the first species, but might benefit the second. In contrast, expanding the boundaries of fragments would help the first frog but not the second.
Population biologist Karen R. Lips of St. Lawrence University in Canton, N.Y., predicts that such analysis "is going to be really important for park design or selecting land for preserves." However, she adds, "It makes our job much more difficult."
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|Title Annotation:||research on how fragmented habitats affect Andean frogs|
|Article Type:||Brief Article|
|Date:||Jan 3, 1998|
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