The greater Bermuda snail (Poecilozonites bermudensis) — once believed extinct — has been declared safe from extinction after an international breeding and release programme. Rediscovered in Hamilton about a decade ago, fewer than 200 rescued snails formed the seed population for captive breeding efforts at Chester Zoo. More than 100,000 individuals have now been released, and six self-sustaining colonies have been established across Bermuda; an assessment confirming recovery will appear in Oryx.
Once-Extinct Greater Bermuda Snail Restored to Wild After Landmark Breeding Effort
Bermuda snail brought back from extinctionChester Zoo
The greater Bermuda snail (Poecilozonites bermudensis), a button-sized native mollusc once believed to have vanished, has been declared safe from extinction after a multinational conservation programme bred and released more than 100,000 individuals back into Bermuda.
The milestone was announced on Reverse the Red Day (Saturday, Feb. 7), a global day dedicated to reversing biodiversity loss. The recovery was driven by a partnership between the Bermuda government, Canada-based Biolinx Environmental Research and conservation teams at Chester Zoo in the U.K., which bred thousands of snails in specialized facilities before carefully returning them to the island.
The greater Bermuda snail, also known as Poecilozonites bermudensis.Chester Zoo
The species was unexpectedly rediscovered about a decade ago in an alleyway in Hamilton, Bermuda, after having been thought lost. From an initial rescue of fewer than 200 snails, conservationists established captive-breeding programmes and released successive cohorts into protected sites across the island.
It’s every conservationist’s dream to help save a whole species — and that’s exactly what we’ve done.
Tamas Papp, assistant team manager for invertebrates, Chester Zoo
Cluster of greater Bermuda snails, also known as Poecilozonites bermudensis, sitting on leaf of lettuce, being held by researcher.Chester Zoo
More than 100,000 greater Bermuda snails have now been bred in human care and returned to the wild. Teams have established six self-sustaining colonies at protected locations across Bermuda, and an independent assessment confirming the species' recovery is due to be published in Oryx: The International Journal of Conservation.
It is remarkable to think we only began with fewer than 200 snails and have now released over 100,000.
Dr. Mark Outerbridge, wildlife ecologist, Bermuda Department of Environment and Natural Resources
Cluster of greater Bermuda snails, also known as Poecilozonites bermudensis.Chester Zoo
The greater Bermuda snail’s past decline was caused by habitat loss, climate change and introduced predators, including wolf snails and carnivorous flatworms. Beyond their small size, these snails play important roles in nutrient recycling and supporting local food webs.
They nearly vanished, so being able to say the snails are now safe from extinction is amazing. It is very rare for a team to be able to announce that, having brought animals into human care and released them, their work is done.
Gerardo Garcia, animal and plant director, Chester Zoo
This recovery is being hailed by conservationists as a rare, career-defining success and a practical example of how targeted international collaboration, captive breeding and careful reintroduction can reverse biodiversity loss.
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