CONSERVATIONISTS from the UK – including in Chester Zoo – and Portugal have launched a dramatic rescue mission to save a group of rare snails from extinction.

The Desertas Island land snails were thought to have disappeared altogether, having not been recorded living for more than 100 years.

However, experts have rediscovered tiny populations of two species of the snail, each consisting of fewer than 300 surviving individuals, on an isolated island in the Madeira Archipelago in the North Atlantic Ocean. The snails are now believed to be the very last of their kind on the planet.

Now, the snails are part of a unique conservation recovery plan supported by the International Union for the Conservation of Nature (IUCN). Around 60 individuals from each group were carefully collected from the island and flown 1,500 miles to the UK, where specialists at Chester Zoo and Bristol Zoological Society are leading the last-ditch attempt to boost numbers and save the species.

Two species of land snails, thought to be extinct for more than 100 years, have been rediscovered on a small isolated island and bred by experts at Chester Zoo.

Two species of land snails, thought to be extinct for more than 100 years, have been rediscovered on a small isolated island and bred by experts at Chester Zoo.

Invertebrate staff at both charity zoos have created special breeding centres which closely replicate the perfect conditions for the snails to reproduce and thrive.

Already, snail experts at Chester have made significant breakthroughs – successfully breeding both species of snail (Discula lyelliana and Geomitra grabhami) for the first time ever in human care. The zoo now has more than 1,200 of the tiny snails under the watch of its experts.

Dr Gerardo Garcia, Chester Zoo’s curator of lower vertebrates and invertebrates, said: “These snails had not been seen for decades and were thought to have gone extinct, so urgent action was required when only a handful of these special snails were found clinging on to survival.

“Starting with just 20 of the last known individuals on the planet from each group, there was a lot of pressure to find answers quickly, but with the technical knowledge, scientific underpinning and the skills developed here at the zoo with other highly endangered invertebrates, our team was able to develop the ideal breeding conditions.

Two species of land snails, thought to be extinct for more than 100 years, have been rediscovered on a small isolated island and bred by experts at Chester Zoo.

Two species of land snails, thought to be extinct for more than 100 years, have been rediscovered on a small isolated island and bred by experts at Chester Zoo.

"Now, with more than 1,200 safely in our care, we can say that we have prevented two magnificent species from becoming extinct, which is an incredible achievement.

“This is just the first step in our recovery plan and, looking ahead, the snails here will form a safety-net population and become part of an international breeding programme that provides a sustainable future for the species.

"We’re also hopeful that many of the snails bred here will be reintroduced to some of the surrounding Desertas islands, once work is completed to restore habitat and remove the invasive species that have devastated the islands – allowing the snails and other endemic species to flourish.”

The Desertas Islands, where the snails were found, are now protected nature reserves under Portuguese and European law and have been recognised as biodiversity hotspots for rare invertebrates, birds and reptiles.

Following the rediscovery, both species have now been listed as critically endangered by the International Union for the Conservation of Nature (IUCN).

Dinarte Teixeira, malacologist for the Instituto das Florestas e Conservação da Natureza (IFCN) in Madeira, added: "This project is a dramatic call for action to protect this unique land snails species. They are currently restricted to small pockets of refuge, genetically isolated, having been fiercely predated by invasive mice.

Two species of land snails, thought to be extinct for more than 100 years, have been rediscovered on a small isolated island and bred by experts at Chester Zoo.

Two species of land snails, thought to be extinct for more than 100 years, have been rediscovered on a small isolated island and bred by experts at Chester Zoo.

"After more than 100 years without live records, their rediscovery enables us to implement immediate conservation actions directed to these snails.

“We are also eager to learn more about the species ecology and its requirements, where little is known. The field data collected will be decisive when deciding about future population reinforcement or species reintroduction in nearby islands.

“All critical information will be part of the species conservation plan and we are confident that we will be able to make the best-informed decision about the conservation of these unique land snails."

The bid to save the snails comes as they were feared to have already been lost forever and no surviving populations had been found for more than 100 years. The snails’ main threats are invasive mice and goat species – introduced by human settlers – predating on the snails and destroying their habitat.

While conservationists work to restore and replant the habitat on the islands, as well as managing the invasive animal populations, a number of the animals bred at Chester Zoo will be reintroduced to new locations in the region.

Some of the surrounding islands have largely been left untouched by humans and are free from the snails’ predators – providing a perfect sanctuary for the new boosted populations to thrive in the wild.

The successful project between wildlife conservation organisations Chester Zoo, Bristol Zoological Society, Mossy Earth and the Madeiran Government in Portugal, is set to be used as a blueprint for helping other endangered reptiles and invertebrates in the region.

Following the success of the breeding breakthrough, an expedition team from IFCN, Chester Zoo and Mossy Earth will be heading to the Desertas islands once more to help with reintroduction surveys and to attempt to rescue a further two critically endangered snail species in a bid to help prevent their extinction.

Mike Jordan, Chester Zoo’s animal and plant director, said: “This year we have launched our Conservation Masterplan, which is the blueprint for increasing our conservation work even more over the next 10 years.

"As part of this we have targeted 150 new priority species preservation programmes and our work with Madeiran snails is an important part of this. These are the first two, of five species of Madeiran snails which we have set our sights on saving from extinction and to have such a rapid and profound success with these first two species is absolutely wonderful and epitomises the vital role that Chester Zoo has in saving biodiversity.”