They glow in the dark. Scientists painted tiny UV-reflective dots on their shells so they could track them at night in the forest undergrowth. And then they set 7,000 of them free on the islands they hadn't seen in thirty years.
The Partula snails of French Polynesia were wiped out in one of conservation's most painful cautionary tales. In the 1970s and 80s, a giant predatory snail — the rosy wolf snail — was deliberately introduced to the islands to control another invasive species. Instead, it consumed the native Partula snails with devastating efficiency. Within a decade, multiple species had been driven to complete extinction in the wild.
But 15 zoos across the world refused to let them disappear entirely. They quietly collected survivors, built breeding programmes, and for three decades, they waited for the right moment to bring them home.
That moment has arrived.
**🌟 The Glowing Snails**
In November 2025, conservationists released over 7,000 Partula snails across four islands in French Polynesia — Moorea, Tahiti, Huahine, and Raiatea — the largest single release of these species ever conducted.
To track such tiny, nocturnal creatures in tropical forest at night, researchers developed an elegant solution: **UV-reflective paint applied to their shells**. Under ultraviolet torchlight, the snails glow in the darkness — visible, trackable, and identifiable even months after release.
**A World First: From Extinct to Critically Endangered**
The results are extraordinary. In March 2025, the IUCN officially reclassified *Partula tohiveana* from **'Extinct in the Wild'** to **'Critically Endangered'** — the first time in history that an invertebrate species declared Extinct in the Wild has been successfully re-established through coordinated zoo conservation.
Wild-born adult *Partula tohiveana* individuals were discovered on Moorea in 2024 — snails born in the forest from parents returned by conservationists. And then something even more remarkable: **they were found living outside their original release area**, evidence that the population is expanding its range.
A second species — *Partula varia* — produced an unmarked, wild-born juvenile on the island of Huahine: the first wild-born member of that species spotted in over 30 years.
**Thirty Years of Quiet Dedication**
Behind this moment is a coalition of 15 zoos — including ZSL London Zoo, Edinburgh Zoo, and Jersey Zoo — who maintained breeding populations across three decades. In total, more than **30,000 snails** from 10 extinct-in-the-wild species and subspecies have been reintroduced over the last ten years.
'Finding wild-born Partula snails in French Polynesia — snails born free in the forests their ancestors once roamed — is the realisation of everything this programme has worked toward for three decades.' — ZSL London Zoo conservation team
**Why Snails Matter**
Partula snails are essential to the health of French Polynesian forest ecosystems, where they play a critical role as vegetation recyclers — breaking down dead plant matter and cycling nutrients back into the soil. Their loss was a quiet catastrophe for forest health across the islands.
Thirty years ago, people thought these snails were gone forever. Today, they are glowing in the dark in the forests of French Polynesia, finding their own way home. 🐌✨
Sources: ZSL London Zoo · Edinburgh Zoo · IUCN Red List · Gizmodo · Cambridge University