PREVIEW

**THIS STORY IS EMBARGOED UNTIL 00.01 TUESDAY JULY 28**

BY MARK WORGAN

Hundreds of tiny endangered snails have been returned to a remote Atlantic island after an unprecedented conservation breeding programme helped save four species from the brink of extinction.

The snails have been reintroduced to Bugio, part of Portugal's Madeiran archipelago, where conservationists hope they will help restore the island's ecosystem following decades of damage caused by invasive mammals.

Experts from Chester Zoo in the UK and ZooParc de Beauval in France were asked by the Madeiran government to establish breeding populations after the last surviving wild snails were rescued from the islands.

Among those rescued were 21 Geomitra coronula, believed to represent the species' final remaining wild population. The snails were discovered beneath a single rock.

More than 300 descendants of those snails, bred at Chester Zoo, have now been released on Bugio alongside 270 Discula lyelliana bred by specialists at ZooParc de Beauval.

The islands' native woodland was gradually destroyed over centuries, while introduced goats and rabbits prevented vegetation from recovering. Mice, which were also introduced by humans, preyed on the snails for moisture because there are no natural freshwater sources on the islands.

Tamas Papp, Assistant Team Manager for Invertebrates at Chester Zoo, said: “It had to be a rapid rescue mission for all four species of snail. Over the course of a few hundred years, people managed to destroy the islands’ woodland and introduced rabbits and goats, which prevented native plants from regrowing. Worse still, they accidentally brought mice with them. With no natural sources of drinking water on the islands, the mice quickly turned to the snails, whose bodies are made up of around 80% water, using them as a vital source of hydration. As a result, snail populations were wiped out.

“By the time the Madeira government contacted us for help, one of the species, Geomitra coronula, was so close to extinction that its entire global population could fit inside a single petri dish. We knew we had one shot to save them. If we missed this chance, that was it - they were gone.”

Before the reintroductions, conservationists working for the Madeiran government removed invasive species and restored habitats on Bugio. The work was also intended to benefit threatened seabirds that breed on the islands.

Dinarte Teixeira, a conservation biologist with the Institute of Forests and Nature Conservation (IFCN), coordinated the rescue effort, selected release sites on Bugio and Deserta Grande, and continues to monitor the snail populations.

He said: “The Desertas islands are the only place in the world where these precious snails can be found. For 100 years we thought they’d gone forever, but thanks to this team effort, these reintroductions are proving successful. We will keep monitoring the snails as the settle back into the wild."

Papp, who personally transported more than 300 Geomitra coronula to Bugio, described the release as one of the most demanding conservation projects he had worked on.

He added: “It might be the trickiest reintroduction we’ve ever done. We had a short window due to rough weather, and there’s no jetty on the island. We had to jump straight into the water, climb out, put helmets and harnesses on, and start scrambling up the cliff face. It took us two hours to navigate less than two miles.”