June 22, 2005
Extinction of Frogs is Catastrophic, Scientists Say
QUITO, Ecuador -- Before the arrival of Spanish colonizers some 500 years ago, Indians in what is now Ecuador dipped their arrowheads in venom extracted from the phantasmal poison frog to doom their victims to convulsive death, scientists believe.
More recently, epibatidine -- the chemical which paralyzed and killed the Indians' enemies -- has been isolated to produce a pain killer 200 times more powerful than morphine, but without that drug's addictive and toxic side effects.Pharmaceutical companies have not yet brought epibatidine to market but hope to discover other chemicals with powerful properties in frogs, which are a traditional source of medicine and food for many of Ecuador's Indians.
They may want to hurry because the treasure trove of the world's frogs and toads is disappearing at a catastrophic rate. And it's not just potential medicines which could be vanishing but creatures of beauty.
"Frogs and toads are becoming extinct all over the world. It's the same magnitude event as the extinction of the dinosaurs," said Luis Coloma, a herpetologist, or scientist dedicated to studying reptiles and amphibians, in Ecuador -- the country with the third-greatest diversity of amphibians.
The thumb-sized jungle-dwelling phantasmal poison frog is an example of amphibian good looks, despite its macabre associations. It is bright red with fluorescent green stripes.
At least two out of five of the 3,046 amphibian types in the Americas -- home to 53 percent of known species -- are threatened with extinction, according to a recent report titled "Disappearing Jewels" by lobby group NatureServe.
Nine amphibians, including eight frogs and a salamander, have become extinct in the Americas in the last 100 years, including five since 1980, according to the report. Scientists have also been unable to find representatives of another 117 species, which are also possibly extinct.
Toads and frogs are dying out under pressure from the expansion of agriculture, forestry, pollution, disease and climate change, NatureServe said.
"Amphibians are disappearing before our eyes," the report said.
Scientists fear they could be indicator species -- a sign of possible future damage to other parts of the ecosystem because frogs and toads are especially vulnerable and thus are the first to disappear.
"Disappearing amphibians break links in the food chain, with often unpredictable effects on other organisms," the report said.
Governments should strengthen controls at existing nature reserves and encourage the breeding of endangered species in captivity if they are to save frogs, NatureServe says.
They should also foster research on the recently discovered chytrid fungal disease, which is killing frogs, and educate the public about the plight of amphibians, it said.
"We have to change the idea that they are ugly and slimy. They are beautiful, diverse species, just like hummingbirds or butterflies," said Martin Bustamante, herpetologist at Ecuador's Catholic University.
The Catholic University possesses one of the largest collections of captive live frogs in the Americas, and, to boost public awareness of frogs and toads and their tribulations, it recently staged an exhibition of some of its charges in the capital Quito.
The jungles and mountains of Ecuador are home to 417 species of frogs and toads, of which more than a third are classed as vulnerable or in critical danger of extinction. In the Americas, only Colombia and Mexico are home to more endangered amphibians, according to NatureServe.