Powelliphanta hochstetteri - photo Ruth Bollongino
Rhytida oconnori - photo Ruth Bollongino
Never before have the rare, carnivorous snails been studied so intensively in the Abel Tasman.
In the spring of 2016 Dr Brian Lloyd, assisted by Dr Ruth Bollongino, attached tiny radio transmitters to ten Powelliphanta hochstetteri snails near Canaan Downs to investigate their ranging behaviour and activity. The snails in this study were from the sub-species P.h. hochstetteri, ranked as nationally endangered. They were monitored, day and night for the next 41 days.
This is the first time snails have been radio-tracked at night in New Zealand, giving a unique insight into the carnivorous land snail’s behaviour. Results found snails are active for one or two nights and then have longer periods of inactivity, preferring to move on warm, moist nights. Unsurprisingly they don’t travel great distances, on average just 1.32m, although one did travel 3.8m.
Interestingly, the snails tended to move in a straight line with a slight left bias. None went back to the same spot which indicates they are not territorial and don’t seem to have a home base.
A Powelliphanta snail with its transmitter - photo Ruth Bollongino