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Geographica
Conservation

Big Frog—Really Big
But vulnerable to deforestation, pollution, cook pots

Its foot dwarfs a man's palm, it's as heavy as a house cat, and, for those who've had reason to hold one, it feels like a balloon stuffed with wet sand. The goliath frog, Conraua goliath, lives exclusively along isolated rivers in the rain forests of Cameroon and Equatorial Guinea, where it's embedded in local folklore (Mbo tribesmen believe the frogs are wizards of sacred waterfalls). But its habitat—forests boasting the most amphibian species in West Africa—is rapidly disappearing, threatening to take the world's largest frog with it.

It's not easy being big. At a foot long (30 centimeters) and seven pounds (three kilograms) in weight, goliaths are the offensive linemen of the amphibian world—slow, steady, but weary after a few hops. Their size intrigued collectors and zoos a decade ago: Many frogs were snatched up and exported to the U.S. for jumping contests (a short-lived fad) and captive breeding (a flop).

But these days the chief threats to the goliath are on the home front. Commercial logging has decimated areas where frogs once took refuge. "About half their original habitat is lost or seriously damaged," says Chris Wild of the San Diego Zoo's Center for Reproduction of Endangered Species (CRES).

Meanwhile, agrochemicals used illegally in fishing are turning rivers toxic. This could be disastrous for an animal that relies on ten central African river systems—for hunting in rapids, cooling off in waterfalls, and spawning in rocky pools.

Finally, more frogs are being caught and sold for food as hunters gain access to logged wilderness. "At local markets sometimes 70 frogs can be seen at a time," says Wild. "They're considered pure, associated with clean-water spirits and good for pregnant women. And they taste sweet too." Local restaurateurs pay about five dollars apiece for a big one.

CRES and the World Wide Fund for Nature, with Cameroon's Department of Wildlife and Protected Areas, are trying to preserve frog habitat, which is shrinking by more than 200,000 acres (80,000 hectares) a year. Earlier this year three wildlife sanctuaries in Littoral Province were approved, and a river management plan may follow. If properly enforced, protective laws can make a dent. Still, says Wild, the root cause of the destruction—commercial logging fueled by consumer demand—is not easily stemmed.

When Geographic last reported on goliaths, in July 1967, Paul Zahl described an uninviting habitat and limited hunting. "Unless these factors change, their survival seems assured," he wrote then. No longer.

—Jennifer Steinberg Holland



Web Links

American Museum of Natural History
www.amnh.org/nationalcenter/Endangered/frog/frog.html
This site provides a good general description of the goliath frog as well as some information on the apparent worldwide decline in amphibians.

AmphibiaWeb
elib.cs.berkeley.edu/aw/search/index.html
A comprehensive database of amphibian species worldwide, this site is searchable by scientific name, common name, or country. If you look up the goliath frog, you'll find a detailed physical description as well as a discussion of the frog's distribution and habitat.


Free World Map
Bibliography

Zahl, Paul A. "In Quest of the World's Largest Frog," National Geographic (July 1967), 146-52.



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