In a momentous victory for conservation, over 1,300 critically endangered land snails have been reintroduced to their ancestral home on a remote island in the Atlantic Ocean. The Desertas Island land snails, no bigger than a pea, were feared extinct for more than a century until their rediscovery less than a decade ago. Now, thanks to a dedicated captive breeding program, these resilient molluscs are getting a second chance at survival in the wild.
Rescuing the Desertas Island Snails
The Desertas Island land snails once thrived on the windswept slopes of Deserta Grande, an uninhabited island near Madeira, Portugal. But as invasive predators like rats and goats proliferated, the tiny snails vanished, unrecorded for generations. Amazingly, expeditions between 2012-2017 by Madeiran wildlife officials located remnant populations of two snail species clinging to survival – barely 200 individuals in total.
Conservationists leapt into action, collecting the remaining snails to initiate an emergency captive breeding program. Chester Zoo in England and other European zoos stepped up to devise first-ever husbandry protocols for these mysterious micro-molluscs. According to invertebrate specialist Heather Prince:
“Within a few months we were able to crack the breeding of the Desertas land snails. Crucially, we were then successful in breeding multiple generations. This was key, because it meant we could then bring in the support of other zoos and establish a network, breeding them in the substantial numbers needed to have a chance of saving the species.”
Homecoming to Bugio Island
The captive-bred snails are now being released on Bugio, a neighboring island that’s been a strict nature reserve since 1990. Here, away from human disturbance, threats like invasive rats and goats have been systematically eradicated to restore native habitat. Each reintroduced snail has been marked to allow ongoing monitoring of this pioneering population.
The Desertas Island snails’ return marks a full-circle journey from the brink of extinction to a tentative reestablishment in the wild. As some of the rarest creatures on Earth, entirely restricted to the remote Desertas islands, their future still hangs in a delicate balance. Chester Zoo curator Gerardo Garcia mused:
“As a zoo conservation community, we knew nothing about them. They’d never been in human care before and we had to start from a blank piece of paper and try to figure out what makes them tick.”
Safeguarding Island Biodiversity
Islands like Bugio are biodiversity hotspots, home to unique species found nowhere else. But their isolation also leaves them vulnerable – 75% of recorded animal extinctions have occurred on islands. Desertas Island snails are a poignant example of how quickly endemic island species can decline when faced with novel threats.
Their story also showcases the power of collaborative conservation to bring endangered species back from the edge. As Dinarte Teixeira of the Madeiran wildlife institute affirmed:
“These snails are incredibly precious. The Desertas Islands are the only place in the world where they can be found and so we’re striving to do everything we can to give them the best possible chance for the future. For 100 years we thought they’d gone for ever, but now there’s new hope.”
With the first 1,300 snails now back home on Bugio, conservationists dare to dream of a revitalized future for these one-of-a-kind invertebrates. As living proof of how even the smallest creatures can rebound through dedicated human effort, the Desertas Island snails carry immense ecological and symbolic importance. Their reintroduction is a vital first step in restoring and safeguarding the precarious island ecosystems they call home.
