Difficulty: Challenger (Level 2)
Hundreds of tiny snails have been brought back to a rocky island in the Atlantic Ocean after a breeding programme was set up to save them.
The government of Madeira asked experts from Chester Zoo and the ZooParc de Beauval in France for help. Their job was to protect four types of snails found only on the Deserta Islands. These islands are part of the Madeira group of islands in the Atlantic Ocean.
A small number of snails were sent to different institutions, including 21 of the type called Geomitra coronula. These snails were believed to be the last remaining examples of their kind. They were found holding on under a single rock on Bugio Island.
More than 300 young snails that were raised at Chester Zoo have been sent back to live in the wild on the island. In addition, 270 snails from the species Discula lyelliana, which were bred by experts in France, have also been released into the wild.
Chester Zoo is now looking after all four species, Atlantica calathoides, Geomitra grabhami, Geomitra coronula and Discula lyelliana, in breeding pods similar to their natural environment.
“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 … If we missed this chance, that was it – they were gone,” said Tamas Papp, who works at Chester Zoo.
Despite their small size, snails are important to the ecosystem (see graphic).
Over hundreds of years, people cut down many trees on the islands. They also brought in rabbits and goats. These animals ate the native plants, which stopped them from growing back.
At the same time, mice came to the islands. They used the snails for water because the islands are very dry. This made the snails disappear.
