Threats to Powelliphanta snails
Kath Walker in DOC uniform with
hundreds of snails which have been
predated by rats and possums
Despite being legally protected, New Zealand's Powelliphanta land snails are under serious threat. Several species are in danger of extinction, particularly from predation and habitat loss.
The main predators are possums, pigs and rats, although weka, thrushes and hedgehogs also eat them. Possums only recently developed a taste for the snails, and appear to be incorporating them into their diet over increasing areas.
As a result of major habitat loss in the past, many Powelliphanta populations are now restricted to tiny pockets of native bush, where they have a precarious toehold on existence.
These isolated populations can be threatened further if the bush is removed, opened up by stock trampling or dried out by drainage of nearby paddocks, as the snails need moist conditions to survive.
1080 poison helps native snails
Possums cause massive problems for New Zealand's native species.
This video explains how periodic use of the biodegradable poison 1080 to kill possums has reversed the decline in snail populations.
Video by Trakabat
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