2 Dec 2021

Conservationists from the UK 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 on an isolated island in the Madeira Archipelago in the North Atlantic Ocean. Each population consists of fewer than 300 surviving individuals and are now believed to be the very last of their kind on the planet.

The snails are now part of a unique conservation recovery plan supported by the International Union for the Conservation of Nature (IUCN). Around 60 individuals from each group have been carefully collected from the island and flown 1,500 miles to the UK. Specialists at our zoo and Bristol Zoological Society are leading the last ditch attempt to boost numbers and save the species.

Invertebrate staff at both charity zoos are world-renowned for their technical knowledge and species-saving work. They have created special breeding centres which closely replicate the perfect conditions for the snails to reproduce and thrive.

Our snail experts have already 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.

“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.”

Dr Gerardo Garcia, our Curator of Lower Vertebrates and Invertebrates.

Dr Garcia continued to say:

“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. 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.

Also following the rediscovery, both species of snail have 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, explained that:

“This project is a dramatic call for action to protect this unique land snails species. They’re currently restricted to small pockets of refuge, genetically isolated, having been fiercely predated by invasive mice. After more than 100 years without live records, their rediscovery enables us to implement immediate conservation actions directed to these snails.

“We’re 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’re confident that we’ll 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 hard to restore and replant the habitat on the islands, as well as managing the invasive animal populations, a number of the animals bred at the 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. This provides a perfect sanctuary for the new boosted populations to thrive in the wild!

Mark Bushell, Curator of Invertebrates at Bristol Zoo, added:

“These snails are a vital part of the natural ecosystem on the Desertas Islands and are found nowhere else on the planet, so to be able to play a part in securing the future of these species is a huge privilege.

“We will draw on the wealth of knowledge and experience that we have from decades spent breeding and caring for a range of other critically endangered snail species, and use this to ensure this species is given the best possible chance for the future.

“Collaborative projects such as this are testament to the vital role that good zoos play in safeguarding at-risk species, working together to safeguard threatened species and habitats all over the world.”

Tiago, Conservation Biologist at Mossy Earth, added: “The situation with Madeira’s land snails is very worrying but we hope that this project will showcase how targeted efforts can turn things around. At Mossy Earth we often focus on neglected causes as a way to have the greatest impact and that’s why we are very excited about contributing to support the fieldwork needed to carry out this snail species rescue operation.”

Mike Jordan, our Animal & 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.”

The successful project between leading wildlife conservation organisations here at 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. Conservationists state that more than 20 other highly endangered species require urgent attention and this model can now be replicated to help prevent their extinction.

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. We’ll attempt to rescue two more critically endangered snail species in a bid to help prevent their extinction.