'Ark' Designed to Save Imperiled Amphibians
Monday, May 12, 2008
NEW YORK -- The 300 Kihansi spray toads residing in a small room at the Bronx Zoo chirp cheerily as they bask in a light sprinkling of water 14 times a day. Until a few years ago, the tiny, mustard-colored toads existed only in a river gorge in Tanzania. Now the survivors are confined to the Bronx and Toledo zoos, having gone extinct in the wild.
With thousands of amphibian species facing unprecedented threats to their survival, scientists have launched a global effort to collect them in zoos in an attempt to save them from disappearing altogether. The program, called Amphibian Ark, aims to keep 500 species in captivity and breed enough to eventually reintroduce them into the wild.
"In terms of scope, I think this is the biggest conservation project that humanity has ever tried to tackle," said Kevin Zippel, the program's director, who said the initiative is testing zoos' ability to raise and maintain animals with specialized needs. "In the course of the last four years, we've realized how badly off amphibians are," he said.
Scientists have been tracking the rapid disappearance of amphibians for two decades, but new evidence suggests the animals face increasingly grave peril. A third to a half of all amphibians are now threatened with extinction; 165 species have already vanished. In Latin America and the Caribbean alone, three of every four amphibian species are critically endangered.
Research published Wednesday in PLOS One, a journal of the Public Library of Science, estimated that in the neotropic region, which spans from the Mexican deserts to Patagonia in southern Argentina, 35 percent of amphibians "are threatened by habitat loss, habitat fragmentation, and habitat split."
In response, members of the Association of Zoos and Aquariums, along with other institutions worldwide, have declared 2008 the "Year of the Frog" in an initiative to raise awareness of amphibians' plight and the roughly $440 million needed to conduct research, maintain captive species and preserve critical habitat worldwide.
"I don't think we're going to save everything we bring into captivity," said R. Andrew Odum, the Toledo Zoo's curator of herpetology, but "it's important that we try."
To give them the best chance of success, scientists are distributing amphibians to zoos around across the globe to create "assurance populations" that could potentially repopulate the wild.
Among them are 120 Panamanian golden frogs being kept at the District's National Zoo, among the 2,000 of the species now in 50 U.S. zoos.
"If you put all your eggs in one basket, you really have one basket," said Brian Gratwicke, an amphibian conservation biologist at the National Zoo, explaining why species are being kept at multiple zoos.
There are a number of reasons that frogs, toads, salamanders and wormlike caecilians are in peril.
Climate change is altering many habitats, forcing some species to move to ever-higher elevations to survive. Increased traffic poses a problem when the creatures migrate across roadways. A recent survey of Indiana highways, reported in the journal Herpetological Conservation and Biology, found that amphibians and reptiles accounted for 95 percent of roadkill. In Appalachia, mountaintop-removal mining threatens several species of salamanders, which can take 70 years to recover from such drastic disruptions.