Partula tree snails and the Euglandina threat
Partula snails Partula conservation Euglandina

Partula conservation

With the extinction of most Partula species following the introduction of the carnivorous snail Euglandina rosea conservation effort has mainly focussed on the captive breeding of the few surviving species. 11 species survive only in captivity and just 5 species still exist in the wild in French Polynesia. The captive breeding programme for the surviving species has been in place since the early 1990s and many species have existed only in small boxes in controlled conditions for many generations. Efforts are underway to find a way of returning them to the wild. This requires new approaches to conservation and reintroduction as there is no realistic prospect of eliminating Euglandina and a more recently introduced predator, the New Guinea flatworm Platydemus manokwari. Instead, are finding ways of enabling Partula to coexist with its introduced enemies. This met with success in 2024, with the first species being successfully re-established in the wild.



Zoos participating in the conservation breeding programme

  • Bristol Zoo, Detroit Zoo, Disney's Animal Kingdom, Edinburgh Zoo, London Zoo, Marwell Zoo, Randers Regnskov, Riga Zoo, Roger Williams Park Zoo St. Louis Zoo, Schwerin Zoo, Whipsnade Wildlife Park, Wild Discovery Zoo, Woodland Park Zoo

    Prospects for the future

    Rescuing Partula from extinction is challenging. Small predator-proof reserves can be created and captive-bred Partula released into these, most recently in 2015 on Tahiti. Although this can work, they are very small, costly to establish and require constant maintenance to keep the defences secure. What is needed is a new solution to the problem and here research may offer hope. Not all the Partula were wiped out by Euglandina; five species survive, mostly in high sites that the predators have not reached yet, or are still too cold for them. There are some populations though which seem to coexist with the predators, although in greatly reduced numbers. It appears that there are some plants that make it hard for the predators to find their prey. This observation has led to a new conservation strategy: releasing captive-bred snails back into forests and trying to protect them from predators. Results so far suggest that this strategy may allow Partula to return to the wild. There they may be able to adapt to the presence of predators and start to take their natural part in the ecology of the islands. Release efforts since 2016 are now starting to show signs of success and there is some evidence that at least two species are once again established in the wild.

    Other pages give a summary of recent events in the conservation programme.

    • Compiled by Justin Gerlach: contact

    Hosted by Island Biodiversity