LONDON, June 14 (Xinhua) -- Rescued from extinction, 4,000 critically endangered Greater Bermuda snails are being sent by air mail -- rather than snail mail -- to Bermuda, conservationists at Britain's Chester Zoo announced Thursday.
The snail was believed to be extinct until a few individuals were discovered still alive, which led to Chester Zoo establishing an emergency conservation breeding program that has seen 4,000 snails returned to the wild.
The snail (Poecilozonites bermudensis), which measures around 2cm and lives only on the remote, oceanic islands of Bermuda, was driven almost to extinction by predation from introduced species of carnivorous snails and flatworms.
Feared to have vanished completely until a small number were rediscovered in 2014, fewer than 200 are currently estimated to remain in the wild.
Over the past three years, a population of the snails has been established at Chester Zoo as part of a breeding program to rescue the species after receiving a plea for help from the Bermudian government.
Chester zookeeper Heather Prince, joined by snail specialist Dr Kristiina Ovaska and wildlife ecologist Dr Mark Outerbridge from the Bermudian government, has taken the snails home.
The snails are being released on Nonsuch Island in Bermuda, an island nature reserve which has been chosen as an ideal location for the reintroduction following extensive field research. The island can only be accessed under strict quarantine protocols to prevent the unwanted introduction of alien species.
To track the snails and chart their progress, some will be fitted with fluorescent tags, a unique observation technique trialed by Ovaska and the team from Chester Zoo.
The tags will enable conservationists to monitor their dispersal, growth rates, activity patterns, population size and, ultimately, the overall success of the reintroduction.
It is incredible to be involved in a project that has prevented the extinction of a species, said Dr Gerardo Garcia, the zoo's curator of lower vertebrates and invertebrates.
"The Bermuda snail is one of Bermuda's oldest endemic animal inhabitants. It has survived radical changes to the landscape and ecology on the remote oceanic islands of Bermuda over a million years but, since the 1950s and 60s, it has declined rapidly. In the early 1990s, it was actually believed to be extinct until it was discovered again in one remote location in 2014," he said.
"It wasn't too long ago that we considered this species extinct, but because of the serendipitous rediscovery of a relict population on Bermuda and the dedicated care that our UK partners have shown in propagating them, there are now 4,000 snails being released this month," Outerbridge said.
Several further releases are expected to take place in the coming months, following extensive work to restore important habitat on many of Bermuda's offshore islands.