Kansas City, Mo. ? The Kansas City Zoo is offering to become a haven for frogs and salamanders that are coming perilously close to extinction.

Kansas City is one of several zoos, aquariums and botanical gardens throughout the country that will be part of a worldwide “Amphibian Ark,” which seeks to establish captive breeding programs to help endangered amphibians.

“What’s depressing about amphibians is that this is a worldwide trend,” said Jeff Briggler, a herpetologist for the Missouri Department of Conservation. “One-third of them are declining.”

Experts say amphibians are good indicators of ecological health because they are sensitive to chemicals introduced to the environment and changes in wetlands, woodlands and prairies.

“We’re planning to help, although we’re just now getting our frogs in a row,” said Liz Harmon, general curator for the Kansas City Zoo.

The zoo plans to work with two species, including crawfish frogs, a local species listed in Missouri as vulnerable to becoming threatened or endangered.

Crawfish frogs are cream colored with dark spots and grow up to 4 inches long. They live off crayfish or mice burrows in native prairies, and the destruction of their habitat is one reason the species is threatened.

“The hope is that this would be a short-term holding place until there’s a place for these amphibians to go into the wild,” Harmon said.

Green toads of the arid western plains are among the species native to Kansas that could be helped by zoo breeding programs, said Joseph T. Collins, herpetologist at Kansas University. Cricket frog populations are also in decline.

Collins said pollution weakens amphibians, making them more susceptible to disease. Habitat loss and drought are other reasons their populations are declining.

“I’m not sure whether anybody has a handle on the problem,” he said. “Are all the frogs in trouble? We don’t know.”