Saving miniature Madeiran snails from extinction

The Ectotherm team at Bristol Zoological Society have successfully bred two species of Critically Endangered Desertas Island land snails for the first time ever in human care.

Having not been recorded for over 100 years, these minuscule snails were thought to have gone extinct. However, experts recently rediscovered small populations of two species on an isolated island off the eastern tip of Madeira in the north Atlantic. Each population of Critically Endangered Discula lyelliana and Geomitra grabhami are now made up of fewer than 300 individuals, making them the last of their kind on the planet. They can be found on the Desertas Islands, three small uninhabited islands off Madeira, which have been classed as a nature reserve since 1995.

The main threat for these snails has been the invasive species introduced by human settlers, which caused chaos for the island’s fragile ecosystem. These include household mice that feed on the snails and the seeds of the native plants.

Thanks to the International Union for Conservation of Nature (IUCN) and the Instituto das Florestas e Conservação da Natureza (IFCN), these snails are now part of a unique conservation recovery plan. Around 60 individuals from each species were carefully collected and transported 1,500 miles to the UK to be cared for in several zoos.

Last month, we joined 13 participants from various institutions, including Chester Zoo and ZooParc de Beauval, for a 5-day conservation campaign on the Desertas Islands where we prepared the snails, transferred them to the island of Bugio and released them into the wild. We conducted surveys throughout the time to monitor their progress.

Tamara Canalejas, Curator of Ectotherms at Bristol Zoological Society, said: “Our Ectotherm team have made remarkable breakthroughs with this successful breeding programme and we now have 500 Critically Endangered snails in our care here at Bristol Zoological Society.

“When we initially received the species we knew very little about them, but with the team’s experience and skills, and after years of research into how these tiny snails live and reproduce, we’re thrilled to be able to reintroduce them to the wild.

“The Ectotherm team have done an amazing job of breeding these tiny, or rather ‘dinky dinky,’ snails and getting them prepared for their big journey back to the Desertas Islands.”

Here at Bristol Zoological Society we are very excited to be partnering with other conservation leaders as part of this programme and are also working in the same area with the Critically Endangered Desertas Grande wolf spider, Hogna ingens, one of the world’s rarest wolf spiders.

As a conservation charity, we work in nine countries, across four continents, and direct 14 field conservation projects with 31 local partner organisations to conserve and protect some of the world’s most threatened species.

Our contribution to coordinated breeding programmes and worldwide conservation successes has a huge impact on the protection of species, habitat restoration, as well as community engagement and education in the UK, as well as around the world.

We look forward to monitoring the progress of this project and hope to see the species thrive in the wild.

More information on our conservation work can be found below!