The googly-eyed ancient ancestors of frogs, toads, salamanders and newts first swam, crawled and hopped on our planet 350 million years ago. But do amphibians have a future? That was the question asked by scientists who gathered last week in Washington, D.C., for the Amphibian Conservation Summit.
In 2004, a global survey found that almost one-third of the 5,743 known amphibian species are in serious trouble. Populations around the world have declined dramatically in the past 25 years, and many have disappeared entirely. When it comes to amphibians, researcher Christopher Raxworthy of the American Museum of Natural History told TFK, "all the trends are heading in the wrong direction."
Dangers on the Lily Pad
There are several factors that could contribute to the plunge in
amphibian populations, say scientists. The destruction of the native
habitat where amphibians live is probably the biggest threat to these
creatures, says Raxworthy. Forests and wetlands are shrinking as the
land is used to grow food, raise cattle and expand cities. Amphibian
habitats are also lost, or moved, when temperature and moisture
conditions change too much. "A lot of amphibian species occur only in
very small ranges," says Raxworthy. "And when the climate changes in
those areas, amphibians are very poor at moving to other, more
hospitable areas."
Like many other animals, amphibians can be harmed by pollution produced by industry and agriculture. Some researchers believe amphibians may be especially vulnerable to such chemicals because they have more porous skin than other animals. Many amphibians live in or near polluted bodies of water.
A few amphibians are hunted. African goliath frogs and giant Chinese and Japanese salamanders, which can grow to five feet in length and weigh 100 pounds, are hunted as food. Smaller species are eaten in many other parts of the world. The animals are also collected as ingredients for traditional medicines and sold internationally as exotic pets.
A Fungus Among Us
The most recent and mysterious threat to amphibians is a deadly fungus
that is spreading through many countries. The fungus was identified just
six years ago. It causes a disease that seems to kill the animals by
attacking their sensitive skin. Scientists simply don't know much about
it yet. Don Church is a scientist who studies amphibians and reptiles, a
herpetologist, who works with Conservation International. "It's a big
puzzle," he told TFK, "With a lot more research we might be able to
develop some ways of controlling the disease in nature."
A Call to Action
At the Washington, D.C., summit last week, scientists drafted what they
hope will serve as a declaration to save frogs and their kin around the
globe: the Amphibian Conservation Action Plan. One of the key parts of
the plan will be to support governments that take steps to preserve
important amphibian habitats.
Captive breeding programs also show promise. There are a few early success stories with zoos breeding critically endangered species. The spectacular poison dart frogs, which are popular as exotic pets, are now regularly bred in captivity. That means they don't have to be collected in their native habitat. If businesses raise and sell the kinds of amphibians that are often hunted for food or medicine, their wild relatives might be safer.
Making the world safe for amphibians won't be easy or cheap. At the global summit, scientists estimated that it could cost more than $400 million and take many years. But what we will learn in trying to save these special creatures will also help us to better understand the sorts of problems that affect many other kinds of wildlife. And that, says Church, will help us all.