‘Corks pop’ for endangered snails

A new survey has revealed a critically endangered snail found only in the top of the South Island is more widespread than previously thought.

The carnivorous Rhytida oconnori land snail is found only in the Abel Tasman National Park and at Parapara Peak in Golden Bay.

Department of Conservation biodiversity ranger Mike Ogle said proof the critically endangered snail was more prevalent in the Abel Tasman than earlier thought was great news.

‘‘To put this in context, if the Rhytida oconnori had feathers it would be the equivalent of a kakapo as they are both classified nationally critical.

‘‘Imagine finding you had 20 per cent more kakapo than thought, people would be popping the champagne corks,’’ he said.

Historically R.oconnori would have been more widely distributed.

However, in 1998 it was reported as having been reduced to surviving within a one kilometre radius of Pages Saddle, near Harwoods Hole.

DOC undertook the survey as part of Project Janszoon’s work to restore the ecology of the Abel Tasman National Park and to better understand the distribution of both the Rhytida oconnori and Powelliphanta hochstetteri hochstetteri.

Previous studies have shown numbers of both snails were in decline.

Yet the survey found evidence of the land snail up to nine kilometres east and north-east of this area, with most south and west of Awaroa estuary.

The nationally vulnerable P. h. hochstetteri was also found further east and west than previously documented.

Another surprise was finding a high number of P. h. hochstetteri shells at Waterfall Creek.

This was an area that was con- sidered to be out of its range.

‘‘These snails are not like your common garden snails.

Powelliphanta snails are large with deep rich mahogany and gold colouring, many with attractive patterns.

With Rhytida oconnori the beauty is on the inside as its inner shell is like glossy mother of pearl,’’ said Ogle.

The R. oconnori is smaller with a more fragile shall than the P.hochstetteri and both species are vulnerable to predators.

Following the surveys findings, DOC is planning to do some more intensive snail monitoring in the area.