CHESTER, United Kingdom (AFP) — A minuscule snail once thought to have disappeared has been saved from the edge of extinction, a British zoo said Saturday.

The greater Bermuda land snail had not been spotted for years until a cluster of shells was caught slithering through an alleyway in the capital Hamilton in 2014.

Some were flown to Chester Zoo, where experts spent years building up the population before they released thousands back into the wild in 2019.

Unique to Bermuda, this type of snail traces its lineage back over a million years — a relic of the island’s ancient ecosystem.

Now “we can officially say the species is back from the brink”, said Chester Zoo in a statement sent to AFP.

The snail “once thought lost has officially been saved from extinction by experts in Chester Zoo, London Zoo, and Bermuda,” it said.

They confirmed this after a study in the Oryx biodiversity conservation journal found that six colonies of the re-wilded snails had settled successfully on the archipelago.

“The fact that the snails are firmly established in six areas is massive,” said Gerardo Garcia, animal and plant director at Chester Zoo.

From specially designed pods in northwest England, they are now breeding and roaming freely in Bermuda, he said.

“Being able to say that the snails are now safe from extinction is amazing … and something that conservationists might get to say once or maybe twice in their whole career.”

At one point, keeper Katie Kelton said the zoo housed around 60,000 snails.

It was “a lot of snails to look after… a lot of chopping lettuce, sweet potato and carrot”, she told AFP.

The snails faced many threats, including habitat loss, pesticide use and the cannibalistic “wolf snail”.

They were rescued in a process Garcia described as “a war game” with growing numbers tracked by flags pinned across a map of Bermuda.

While they cannot say the species is safe forever, he noted they now knew how to rebuild the population quickly and effectively.

But long-term recovery, he said, would go hand in hand with nature regeneration projects carried out by the Bermudian Government.

Chester Zoo has now turned its attention to the lesser Bermuda land snail — even smaller and much harder to breed.

These snails, which can reach about 23 millimetres (0.9 inches) in length, may now be extinct in the wild.

“We’re considering things like seasonality, how long it takes a colony to establish and the complexity of their environments,” said expert Iri Gill.

But their experience with the greater Bermuda snail should point them “in the right direction”, she said.

“These snails are tiny, but this has been one of the biggest success stories in conservation.”