The Last Population Left On The Planet

On the brink of extinction – Zoo keepers breed world’s last colony of Partula faba snails

                                                       Baby Snail

Photo by Jenny Spencer

One of the world’s most endangered animal species is successfully breeding at Bristol Zoo Gardens.

The tiny young French Polynesian tree snails are just 2mm long and are the latest arrivals in the last population of these snails left anywhere in the world.

The species, known as Partula faba, which is endemic to the Island of Raiatea, is extinct in the wild, and these last snails have recently been given to Bristol Zoo Gardens in a critical effort to help save the species from total extinction through conservation breeding.

Invertebrate experts at the Zoo are carefully nurturing the colony of 88 snails in a custom-built, climate controlled room in the Zoo’s Bug World – the only place in the world where these snails can now be found. The group have now produced 15 offspring – a significant boost to efforts to save the species.

Grier Ewins, is one of the team of keepers who look after the rare snails. She said: “Tree snails are incredibly endangered, with Partula faba being one of the most endangered of them all – they really are on the edge of survival. The great news however, is that this last remaining population of Raiatean tree snails has been steadily growing since we took them on.

She added: “Working with these, and so many other rare animals at the Zoo, is incredibly satisfying. To think that I am nurturing the entire global population of these snails, and encouraging them to breed, is very rewarding – as well as a huge responsibility!

“It shows just how important the role of zoos and other conservation organisations are in helping to breed and protect endangered species, otherwise we risk losing many species forever, which would be a tragedy for us and future generations of people.”

French Polynesian tree snails have been decimated by invasive snails which were introduced to the islands in the 1970s. Between the mid 1970s and mid 1990s an estimated 80 per cent of tree snail species were lost. Loss of habitat, due to highly invasive plants such as the South American velvet tree, is also changing the landscape of the islands and adversely affecting the wildlife.

Currently 20 Partula species have been saved from extinction by Zoos and Universities; 15 are classified as extinct in the wild and five are critically endangered. Five species of Polynesian tree snail are being kept at Bristol Zoo, all of which are part of an international captive breeding programme to save the species.

Bristol Zoo’s Curator of Invertebrates, Warren Spencer, explains his hopes for the future of this species: “Although Raiatean tree snails are extinct in the wild, Bristol Zoo hopes to work with its conservation partners to release some snails into safe ‘zones’ – reserves - back on the island of Raiatea and then to the surrounding area of a new reserve,” he said. “However, this can only be done once we have successfully removed or controlled the spread of the predatory ‘cannibal snail’ which was responsible for this species’ extinction.”

Bristol Zoo also breeds other animal species which are extinct in the wild, such as the Socorro dove, Butterfly splitfin fish, Golden sawfin fish and Potosi pupfish – which was successfully bred last year.

Other critically endangered animals which Bristol Zoo breeds include western lowland gorilla, Indochinese box turtle, Annam leaf turtle and Egyptian tortoise, as well as numerous mammal, bird, fish, invertebrate and amphibian species

For more information about Bristol Zoo Gardens and its conservation projects, visit the website at http://www.bristolzoo.org.uk/  or phone 0117 974 7300.