Chester Zoo

Chester Zoo experts save tiny snails from extinction

Posted: 10th March, 2020

A group of snails, believed to be extinct for more than 15 years, have been released back to the wild by conservationists at Chester Zoo. The 800 lesser Bermuda snails, which were once driven to the brink, have travelled 3,000 miles home to Bermuda, after being bred and reared by the zoo’s invertebrate specialists.

The tiny snails, which can only be found on the remote islands of Bermuda, disappeared after flatworms and carnivorous snails were introduced by humans.

This move follows the 18,000 greater Bermuda snails – a close relative of the lesser Bermuda snail – successfully reintroduced last year by Chester Zoo and the Bermudian government. This year an additional 10,000 greater Bermuda snails have been sent back to boost their number and distribution. It is the first time both species of snails have ever been reintroduced as part of a conservation breeding and release programme in Bermuda.

Dr Gerardo Garcia, the zoo’s Curator of Lower Vertebrates and Invertebrates, said: “It’s an unbelievable feeling to be able to say that we’ve successfully prevented the extinction of two incredibly important snails. The lesser land snails had not been seen in Bermuda since 2004, so the animals we were breeding at the zoo were some of the last surviving individuals on the planet. It really was down to the wire for this species.

“Thankfully, we had already developed a recovery plan for the greater Bermuda snail and had successfully reintroduced thousands of them back to the islands of Bermuda. We’re now continuing with this work in new locations after successfully removing the invasive species and replanting the vital habitat needed for the snails, and other endemic species, to once again thrive. This major recovery plan was used as a blueprint example, which we’ve now applied to a second species. 800 lesser Bermuda snails have now also been successfully bred and returned to the wild – proof that extinction can be prevented.”

The 800 lesser Bermuda snails have been released on to Nonsuch Island, a government owned and managed nature reserve. The greater Bermuda snails have been reintroduced to four new locations, bringing the total to nine islands since reintroduction efforts began last year. The areas were chosen after extensive research highlighted these particular islands as largely untouched and preserved – a result of strict quarantine protocols – providing the perfect haven for the Critically Endangered snails to flourish.

Dr Mark Outerbridge, Wildlife Ecologist for the Department of Environment and Natural Resources of Bermuda, and the zoo’s partner, added: “Now that the snails are safely in Bermuda we will closely monitor their progress. The lesser land snails are so small that we are not likely to find them once they have been released, so for now, we’ve placed them inside a number of large enclosures in order to see how they transition to the wild. They will be fully released after we see evidence of reproduction and adult survival within the next few months.

“These species are some of Bermuda’s oldest animal inhabitants, so to have helped them back from the brink of extinction is a fantastic conservation success story.”

The successful conservation breeding programme is part of a collaborative project between leading conservationists at Chester Zoo, ZSL London Zoo, the Bermudian Government and a snail specialist from British Columbia, Canada.

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