7 Powelliphanta Facts – New Zealand’s Giant Snails

The powelliphanta are giant land snails found only in New Zealand. Here are 7 facts about these unique threatened species.

New Zealand is one of those places where you never know what you are going to find when you take a walk in the bush. The country is full of unique plants and animals that can’t be found elsewhere in the world. We are all familiar with the iconic kiwi, wetas, and other rock stars. But, there are so many other special, lesser known species that you may see, such as the tallest moss in the world, or endemic fungi. I recently had my first glimpse of another one while in Kahurangi National Park, powelliphanta, the country’s giant snails.

Powelliphanta
Photo cc by Kathrin and Stefan Marks.

7 Powelliphanta Facts

There are in fact at least 16 species and 57 subspecies of these snails in New Zealand. They come in a diverse range of sizes and their shells are of various colours and patterns. The largest of them measures about 9 cm across and weighs up to 90 g – that is the same weight as a tui! That is big, but shockingly the largest snails in the world are much bigger.

Powelliphanta
Look at that beautiful shell.

These snails are not very common and can be found in wet forests or tussock areas. In the South Island, they can be found in the Nelson area, over to the west coast, and along the wet coastal mountain ranges all the way down towards Fiordland. In the North Island, they reside in bits of the central mountains and Mt. Taranaki.

Powelliphanta snails are not only large, but they are carnivores. Not quite like a man eating tiger or lion, but they still eat other animals. These snails will slurp up a worm just like a person slurps up a piece of spaghetti. Check out this crazy video to watch one eating.

Powelliphanta
Top photo cc John Barkla.

Similar to some of New Zealand’s other special species, such as kiwi, these animals are nocturnal. They are active at night and if you go for a slow, careful walk at night you may see one. During the day, they spend their time buried under leaf litter or logs.

Powelliphanta
There are lots of shells near the huts on the Heaphy Track. Photo cc by John Barkla.

We walked the Heaphy Track and one of my highlights was heading out at night to look for these giants. I saw heaps of shells around the huts and in the wild, but only managed to see a live powelliphanta once. Good to know they are still alive, but also a bit of a bummer. A local told us how they used to see them much more frequently than now. Yep, these species are now threatened with extinction.

These snails face many threats with the main ones being habitat loss and predation. People have come in and converted their habitat for other uses such as mining. Some of the major predators of these snails are rats, possums, and pigs. It’s not just the introduced species as the native weka also are a serious predator on them.

Powelliphanta
Many of the shells show marks of their demise. Photo cc John Barkla.

As I’ve talked about in other posts, New Zealand’s animals are truly unique and have evolved in wonderful ways. Powelliphanta is like many other native species in that lives for a long time. These snails can live for up to 20 years! That is an incredibly long time for a snail.

Keep in mind that these snails and their shells are protected by law. It’s illegal to take or even to hold a live snail. Feel fortunate if you are lucky enough to see a live one in the wild, but do not touch it or bother it.