Why are 1,329 tiny snails being abandoned on a remote island?

More than 1,300 critically endangered pea-sized snails bred at a zoo have been released to roam (very slowly) on a remote Atlantic island.

The release returns two species of Desertas Island land snails to the wild. They were previously thought to be extinct – no species had been seen for over a century.

When a team of conservationists found a small population surviving on the rocky cliffs of Deserta Grande Island near Madeira, they began a rescue effort.

The snails were brought to zoos in Britain and France, including Chester Zoo, where a home was made for them in a converted shipping container.

The small molluscs are native to the wind-swept, mountainous island of Deserta Grande, just southeast of Madeira. The habitat there has been destroyed by rats, mice and goats brought to the island by humans.

It was believed that all these predatory predators became extinct by eating small snails. Then a series of conservation campaigns – between 2012 and 2017 – proved otherwise.

Conservationists discovered only 200 survivors on the island.

These snails were believed to be the last of their kind, so they were collected and brought into captivity.

At Chester Zoo, the conservation science team built a new home for 60 precious snails. The correct food, plants and conditions were recreated in small habitat tanks.

The 1,329 snail offspring, reared at the zoo, have now been marked with identification dots – using non-toxic pens and nail varnish – and moved back into the wild for release.

“[It’s a] color code,” said Dinarte Teixeira, a biologist at Madeira’s Institute for Nature Conservation and Forestry Conservation. This will allow us to find them and find out how far they spread, how much they grow, how long they survive and how well they adapt. New environment.”

A wild sanctuary for snails has been restored on Baguio, a small neighboring island of Ilhas Desertas (Desert Islands).

Baguio is a nature reserve and invasive species have been eradicated.

Gerardo Garcia from Chester Zoo said the reintroduction was “an important step in the recovery plan for the survivors”.

“If it goes as we hope, more snails will follow next spring. This is a huge team effort that shows it is possible to turn things around for a critically endangered species.”

“These snails are an important part of the natural habitat. [on the islands they come from]”, explained Heather Prince from Chester Zoo. As well as being food for other native species, she explained, snails break down organic matter and bring nutrients to the soil.

“They help plants grow. It’s all down to the little guys — the insects and snails that are often overlooked.”