To keep an amphibian species breeding in captivity, about 50 wild specimens are needed for genetic diversity, estimates Kevin Zippel, the Ark’s program director. Its habitat withered after the Kihansi River was dammed in 2000, and then chytrid arrived the toad has not been seen in the wild since 2003. For example, the Bronx Zoo and Ohio’s Toledo Zoo are now helping save the penny-size, bright yellow Kihansi spray toad, which usually depends on the fine mist from the cascading waters of Kihansi Gorge in Tanzania. The Amphibian Ark hopes to recruit 500 zoos, aquariums, botanical gardens, universities and other institutions to each support a species. Right now zoos around the world are at best equipped to support only about 50 species long-term. Although cases of species raised in captivity and reintroduced into the wild have been documented, the sheer scope of an endeavor targeting an entire group of animals “is unprecedented,” Pramuk says. Pramuk, curator of herpetology (amphibians and reptiles) at New York City’s Bronx Zoo. For instance, one critical breeding pond of the Puerto Rican crested toad “is now a parking lot by the beach,” says Jennifer B. Still, the greatest threat to amphibians overall is damage to or loss of habitat. (Injecting a pregnant woman’s urine into a female frog makes it lay eggs.) Once chytrid finds a suitable area, it can kill half the amphibian species there within three months, and currently scientists have no way to stop or eradicate the fungus in the wild. The most immediate threat to amphibians is a parasitic fungus called amphibian chytrid, which was likely accidentally spread by African clawed frogs shipped worldwide for lab studies and pregnancy tests before the 1950s. In addition, although their thin skins let them easily take in air and water, that thin-ness unfortunately allows pollutants through, too. Now zoos and other institutions worldwide are working together on an “Amphibian Ark” to help save all these species as they vanish in the wild, in the hope of one day returning them home.Īmphibians may be especially vulnerable to extinction because they depend on both land and water-if either habitat suffers, they do as well. Of the roughly 6,000 remaining, up to half are threatened some 500 could go extinct in the next 50 years if not taken into captivity. Since 1980, 122 species may have disappeared. Amphibians are going extinct faster than any other group of organisms.
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