Dozens of critically endangered giant frogs bred in captivity have been released into the wild to help save the species from extinction.
The mountain chicken frog, one of the world's largest - and rarest - frogs, is native only to the Caribbean islands of Montserrat and Dominica and was pushed to the edge of extinction by the spread of the chytrid fungus which affects amphibians.
Now conservationists say they have reintroduced 51 mountain chicken frogs to Montserrat following a successful breeding programme at London Zoo.
In 2009 experts from the Zoological Society of London (ZSL) and Durrell Wildlife Conservation Trust in Jersey warned urgent action was needed to save the species, already affected by hunting and habitat loss, from being wiped out by disease.
A small population of the last remaining healthy frogs was airlifted from Montserrat and transported to custom-built centres in ZSL London Zoo, Durrell, and Parken Zoo in Sweden for a captive breeding programme.
The programme has been a major success, the conservationists said, with 76 frogs reared from just two females at London Zoo in 2012.
A group of the frogs were reared at Durrell and London Zoo before their return to the Caribbean and their release into protected forest on Montserrat.
The mountain chicken frogs - so named because its flesh is said to taste like chicken - have been fitted with tracking devices to monitor them and gain further information to help future conservation efforts, the experts said.
Ben Tapley, head of herpetology at London Zoo, said: "Mountain chicken frogs are one of the most endangered animals on this planet - not only are they facing threats from habitat loss, but their numbers plummeted due to the introduction of the most devastating disease known to amphibians worldwide.
"The rescued frogs and their offspring were kept in a bio-secure, temperature-controlled breeding unit at ZSL London Zoo, to ensure a clean bill of health before their release back to their native habitat in the Caribbean."
The reintroduction this summer has been hailed by conservationists as a huge step forward for the amphibians.
Jeff Dawson, Durrell's amphibian programme officer, added: "The current release in Montserrat is the culmination of our four-year long mountain chicken project on the island, and the team from Durrell and the Department of Environment has been working tirelessly over the last nine weeks radio tracking the released frogs.
"The data collected will help our understanding around the dynamics of this disease in the wild which will be vital in guiding our future conservation actions for this amazing species."