Chester Zoo breeds endangered snails back from brink of extinction

A breeding program at England’s Chester Zoo has restored hundreds of tiny mollusks to their native land after they had grown so rare they could collectively fit inside a petri dish.

The zoo was given a handful of snails from the last known wild population in an effort to save the species, commonly known as the Desertas Island land snail, from extinction. Their habitat in the Madeiran archipelago had been decimated by feral goats, mice and rabbits that grazed the island bare.

With no natural drinking water on the islands, mice turned to the snails for moisture.

Biologists from ZooParc de Beauval in France asked the zoo to step in when they found 21 Geomitra coronula, believed to be the last of their kind, clinging to life beneath a single rock.”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,” said Tamas Papp from the Invertebrates Team at Chester Zoo. “We knew we had one shot to save them. If we missed this chance, that was it—they were gone.”In a rapid rescue mission, more than 300 of the snails’ descendants were bred at Chester Zoo and returned to the wild on Bugio island. Madeiran conservationists prepared for the release by removing invasive species and restoring the island.

Papp, who personally carried the snails, said it may have been the trickiest reintroduction the team had ever done. They had a short window due to rough weather, nowhere to dock, and had to travel at night using red spectrum torches to avoid disturbing rare sea birds sensitive to artificial light.

The released snails measure no bigger than a pea at 8mm, but are important to ecosystem health as they eat vegetation and enrich soil.”Our aim now is to build a network of institutions to support the conservation breeding program,” Papp said, noting the zoo has put out a call across the European network of conservation zoos.