A frog that is reputed to sound and taste like chicken and is treated as a Caribbean delicacy has been rescued from the wild in an effort to save it from extinction.

Mountain chicken frogs are one of hundreds of amphibian species world-wide to be driven to the edge of extinction by a virulent fungus. Five years ago they were so numerous on the island of Dominica that they were eaten as a delicacy, but numbers have dropped since the amphibian chytrid fungus reached the Caribbean.

Conservationists from the Zoological Society of London began a rescue expedition last year but were able to track down only seven of the frogs, which are now kept in permanent quarantine at London Zoo.

The mountain chicken frogs at the zoo, where it is hoped that they will breed, are one of only two groups from the island of Dominica that have been taken into captivity. The other population of 12 frogs is held by a private collector in the United States.

Mountain chicken frogs are also found in Montserrat but have genetic differences from those in Dominica, where the inhabitants are so proud of the amphibian that it forms part of the coat of arms for the island. It was also the national dish until the fungus arrived.

Mountain chicken frogs, which can weigh more than 2lb (0.9kg) and are one of the biggest frogs in the world, breed by laying eggs in a foam-filled burrow. The mother stays near the burrow to feed the tadpoles with infertile eggs until they are ready to fend for themselves.

The chytrid fungus is such a threat to amphibians that it is estimated that 500 species need to be taken into captivity to prevent them from dying out. Scientists estimate that more than a third of all 6,000 amphibian species could die out by the end of the century and about 100 have been identified as likely to be extinct within a decade unless they are protected. Habitat loss and climate change are among the other factors threatening the survival of amphibians.

Conservation groups, including the World Association of Zoos and Aquariums and the World Conservation Union, have declared 2008 the international year of the frog to highlight the plight of amphibians and to focus research on providing a fuller understanding of how the fungus can be controlled.

Sir David Attenborough, who is the patron of the Year of The Frog, said: “Amphibians were the first backboned creatures to colonise the land. They are fascinating. It’s terrible that they are endangered.

“To have a whole section of the animal kingdom facing elimination is a major disaster, the consequences of which are difficult to overemphasise. They are the foundation of many eco-systems.”

London Zoo is one of about 500 zoos around the world that are expected to take part in the Amphibian Ark campaign to save frogs, toads, salamanders, newts and caecilians. In the past two years at least a dozen species of amphibian have been taken from the wild to safeguard their future. An estimated 120 species of amphibian have become extinct since 1980 and 1,891 species are threatened.

The chytrid fungus has caused mass deaths in six countries, including Britain, where its effects are the subject of an urgent research project.

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