The protected Powelliphanta annectens was handed in to a Wellington DOC ranger over the weekend. The would-be snail-nappers realised the ‘empty’ shell they had taken as a souvenir was occupied by a live snail.

Collecting Powelliphanta shells or live snails is illegal under the Wildlife Act and empty shells cannot be held without a permit.

Powelliphanta are among the largest land snails in the world and are some of New Zealand’s most threatened invertebrates.

Nearly two thirds of all species or subspecies of Powelliphanta are ranked as being of national conservation concern due to habitat loss and predation by rats, possums, pigs and thrushes.

DOC Science Advisor Kath Walker says she is glad the people involved did the right thing by handing the snail back.

“Although it will now be expensive and time consuming to get the snail back to its home. Quite honestly, we have better things to do.

“But it would have been more of a concern if it had been released into a park or reserve near Wellington. Powelliphanta are hermaphrodites (individuals carry both sex organs) so any snail could potentially be carrying eggs and could start a new colony.

“Moving Powelliphanta to places they don’t belong also upsets the balance of the resident invertebrate communities, including its existing native land snails.

“Most of these snails are ‘spot endemics’ meaning they are extremely localised with each species confined to just one small area. Illegal translocations destroy these amazing natural biogeographical patterns.

“Unlike the common garden snail, a pest introduced to New Zealand from the United Kingdom which eats your lettuces, Powelliphanta don’t eat plants but instead prey on earthworms and slugs.”

DOC has decided not to name or charge the Hamilton-based couple, who mistakenly took and then returned the snail. They weren’t aware that even taking the shell was illegal. They were making a stopover in Wellington after a South Island tramp when they showed off the souvenir shell to their daughter.

One of the pair said, “I felt so bad when I realized it was alive. My daughter gave me a good telling off and quite rightly so. I hardly slept that night!

“I didn’t appreciate – even if he was just a shell - he was part of the food chain to support the rest of his buddies through uptake of nutrients from the old shells.

“I now know a great deal more about these native snails and their shells and I will certainly never move a snail ever again.”

The attractive shells of Powelliphanta have sometimes been targeted by illegal collectors and snails have been killed simply for these sought-after ornaments. Shells of dead snails should be left in the environment as they break down and supply calcium back to living, growing snails.

DOC Wellington Community Ranger Melody McLaughlin said the staff enjoyed babysitting the snail which was stored in the kitchen fridge overnight.

“It’s been pretty cool to meet one of our most endangered critters and help to get it back home.

“This snail had a lucky escape. It has now been carefully packed in damp moss along with a few earthworm snacks for the road.”

Coincidently, DOC conducted their 5-yearly survey of Powelliphanta traversi otakia populations near Otaki just last week. This subspecies is critically endangered and exists only on protected private land with Government-backed covenants.

Intensive pest control is needed for their protection and recovery.

Melody McLaughlin said pest control may now need to be stepped up as a result of the recent surveys.

“Numbers of live snails have unfortunately fallen, and many empty shells showed evidence of rat predation.”

“New Zealand faces a biodiversity crisis. More than 4000 of our native plants and wildlife are threatened or at risk of extinction. The main threats to our biodiversity includes introduced predators such as possums, rats and stoats.

“A continued focus on pest control will continue to make significant gains for recovery of our indigenous wildlife – including these beautiful snails.”