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Dying Out
Over the last several decades, amphibians around the world have been disappearing. Dozens of species have vanished entirely; others are simply becoming harder and harder to find.

In Yosemite National Park in California, three of the seven native frog and toad species are gone, while the population of the remaining four species is dropping. Ten frog species have disappeared from Australia, including the Gastric brooding frog, which hasn't been seen since 1982. In Monteverde, Costa Rica, golden toads which once congregated by the hundreds haven't been seen since 1990. Meanwhile, deformed frogs with missing or extra legs are turning up all over the United States.

Deformed Frog
Deformities such as this, first discovered by school children in Minnesota, are now commonly found in frogs throughout the U.S. [Click for a larger image.] Photo of the courtesy Minnesota Pollution Control Agency.
   
 
RealAudioListen to this National Public Radio report on the U.S. government response to the world-wide phenomena of sick and dying amphimbians, and its impact on humans. Originally aired on NPR's "Morning Edition" of 5-19-98. [Need help?]
   
 

There may be several factors working to harm the world's amphibians. Among these are climate changes, including global warming and thinning of the ozone layer. Destruction of habitat is certainly a problem; when rain forests get chopped down and marshes get filled in, frogs are left with nowhere to go. Pollution is also probably connected to the decline. Since frogs absorb water directly through their skin, they're especially vulnerable to water pollutants like pesticides and acid rain.

A recently-discovered skin fungus may also be responsible. This fungus is believed to slowly suffocate frogs by attacking the skin through which they breathe. It has been detected in the bodies of dead and dying frogs of various species from Panama to Australia. This type of fungus doesn't usually attack frogs, a fact which leads some scientists to think that the frogs are being weakened by other environmental stresses.

Frogs are considered "indicator species," because they are the first to be affected by degradation of the environment. Their dwindling numbers may be a warning to us that our planet is becoming unlivable. No matter what's behind it, the disappearance of frogs is cause for concern. With a combination of conservation and study, we can help keep frogs hopping for another 190 million years.

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Red-eyed tree frog
A red-eyed tree frog (Agalychnis callidryas.) [Click for a larger image.] Photo by Amy Snyder.
 

Useful Frogs
What have frogs done for you lately?Well, to begin with, frogs eat insects that we consider pests. A dwarf puddle frog can eat up to 100 mosquitoes in one night.

Frogs also provide us with food. Frog legs are popular fare throughout Europe, as well as in the southern United States. (They're said to taste a lot like chicken.)

Because frogs' internal anatomy is similar to that of higher animals, they're often used in medical research, for example, to test new drugs. Meanwhile, students learn about anatomy by dissecting frogs, though computerized "virtual dissections" are gaining popularity as a modern alternative.

Frogs' skin is a pharmacological bonanza, containing all manner of interesting compounds. Chemicals recently isolated from the skin of a South American frog have led to the discovery of a pain killer that is more powerful than morphine, yet also less addictive.

 


   
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