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Poison dart frogs: a labor-intensive passion

Poison dart frogs: a labor-intensive passion

Posted: Friday, April 10, 2009 8:01 pm


For The Associated Press

Driving along a suburban road in Ellicott City, Md., you’d never guess you’d just passed an oasis of South and Central American wildlife.

With 500 adult frogs of 20 species — not counting offspring — Sean Stewart’s collection of poison dart frogs is one of the largest anywhere.

They range from creatures no larger than your thumbnail to the 2-inch Phyllobates terribilis, the largest and, in the wild, one of the most poisonous. The tiny, brightly colored frogs are kept in pairs and small groups in about 150 tanks full of live plants and moss.

A visitor may be surprised to see one of Stewart’s staff members casually pick up a frog that’s made a run for it and pop it back into its tank. In fact, there’s no danger — the frogs are not poisonous in captivity.

Stewart owns and breeds more dart frogs than any zoo or aquarium, which rarely have the resources for the labor-intensive care of so many amphibians. Dart frogs appeal to hobbyists who can meet their specialized needs, including high humidity, controlled temperature and live food.

Stewart might have 1,000 baby frogs at once and, in season, up to 800 tadpoles in small cups, each of which need to be cleaned and fed individually.

He has supplied frogs to many institutions, including Chicago’s Shedd Aquarium and the Philadelphia Zoo. But beyond that, the specialized knowledge of private breeders like him makes them a valuable resource.

“We get calls all the time from zoos about how to care for and how to treat illnesses in these animals,” says Stewart. “We’ve had zoos send people to us to train.”

His private customers range from serious collectors to the occasional 10-year-old whose parents are willing to put up with live crickets in the house.

Stewart also is involved with conservation programs in Peru, Costa Rica and Ecuador, and with research projects, including one with a university in Ecuador — on top of his full-time job as an emergency room physician.

But what’s perhaps most interesting about Stewart is that he may be special, but he’s not unique.

“In the dart frog hobby, there tends to be a high percentage of people who are authentically interested in the natural history,” says Ron Skylstad, executive director of Tree Walkers International, a group dedicated to involving hobbyists and individuals in amphibian conservation.

Frog species are currently disappearing at an alarming rate — it’s estimated that one-third to one-half of species are at risk of extinction. As a response to this crisis, TWI runs an Amphibian Stewardship Network, which keeps track of private collections by adding their animals to the International Species Information System (ISIS) database. So far, they’ve enlisted 71 collectors with 1,550 frogs of about 45 species.

The idea is to manage the captive population that’s in private hands to ensure that it’s sustainable, minimizing the number of animals that need to be brought in from the wild. The bigger goal is to bring together the public and private sectors for conservation.

“In a time of dwindling resources and accelerated extinction of frogs in the wild,” says Skylstad, “it doesn’t make sense to ignore people who are investing their own time and money.”

Stewart’s experience with dart frogs goes back 19 years to when he started as an intern at the National Aquarium in Baltimore. For him, collecting is not about the money.

Although prices of rarer frogs can be up to $200 dollars apiece (the average is $75), most of what he makes goes for expenses — such as $600 a month on crickets.

In the wild, the dart frogs “make their poison from a plant alkaloid. No one knows exactly what it is — it’s probably a family of plants, since they’re so widely distributed,” says Stewart. “They probably eat a species of ant, that eats the plant.”

Without that insect in their diet, the captive frogs are safe to touch. While it’s best to avoid excessive handling, that’s for the frogs’ sake: Their skin is delicate and easily damaged.

Their reputation as poisonous is in any case somewhat exaggerated: Even in the wild, only three species are toxic enough to hurt a human, and the poison would need to get into your bloodstream — unlikely with casual contact.

Published in The Messenger 4.10.09