Rare species — once declared extinct in the wild — rediscovered in French Polynesia

On a small island in the South Pacific Ocean, a rare species once declared extinct in the wild has been rediscovered.
Partula tohiveana, or the Moorean viviparous tree snail, was native to French Polynesia before its wild population was decimated by the rosy wolf snail, a carnivorous and invasive species.
In the mid-1980s, the species was officially declared extinct in the wild, the final classification before complete extinction, including in captivity.
For the last 40 years, the tree snail survived in 'carefully controlled' environments in about a dozen zoos as part of a decades-long international conservation effort to restore the species to its native habitat, according to a March 27 news release from the Zoological Society of London.
Now, thanks to those efforts, the species has been downgraded to critically endangered by the IUCN Red List, conservationists said.
In 2015, participating zoos began releasing the snails back into the forests of French Polynesia, marked with an animal-safe UV paint for tracking purposes, according to the Royal Zoological Society of Scotland.
In 2024, after more than 24,000 snails of various Partula species were reintroduced, conservationists made the 'groundbreaking discovery' of wild-born adult Moorean viviparous tree snails, suggesting the species is successfully breeding in its natural habitat, researchers said.
'Seeing a species return from the brink after years of collaborative effort is exactly why we do what we do,' said Paul Pearce-Kelly, senior curator of invertebrates at the Zoological Society of London and head of the international Partula conservation program.
'The resilience of these snails shows what can be achieved when conservationists, governments, and local communities work together to reverse biodiversity loss,' Pearce-Kelly said in the release.
Many Partula snail species went extinct in French Polynesia after the rosy wolf snail was introduced to the islands to control the giant African land snail population, experts said.
Instead of preying on the intended target, the rosy wolf snail showed a preference for the small Partula snails, conservationists said.
Experts said the rosy wolf snail is still present in French Polynesia, but is now rare due to the arrival of another predator — the New Guinea flatworm, Mongabay reported. Scientists said the flatworm, which hunts primarily on the ground, should not pose a major threat to the tree-dwelling Partula snails, the outlet reported.
Partula snails give birth to live young, the size of a pen tip, about every six weeks, according to a species profile from National Geographic. It takes them up to six months to reach sexual maturity, experts said.

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