Kauri snails are found only in northern New Zealand. There are more than one species of kauri snail:
Paryphanta busbyi—up to 79 mm shell diameter, distribution from Kaitaia south (Northland only)
Paryphanta watti—up to 62 mm shell diameter, distribution: northern Northland (Te Paki)
The shell of the kauri snail typically grows to a diameter of 75-millimetres (or as big as your fist), and is shaped like a flattened spiral. Stripes and spirals pattern the rich brown and ochre-coloured shell.
The kauri snail is carnivorous and cannibalistic. Its diet consists of earthworms, insects, insect larvae, and snails. The kauri snail comes out at night to feed on earthworms, slugs and small snails. It envelops its prey, suffocating and crushing it as it withdraws back into its shell. It then devours its meal with the help of its tongue-like radula. This looks like a ribbon covered with thousands of tiny rasping teeth, something like a cat’s tongue. All snails have teeth, tiny microscopic ones and they have lots of them. In fact they have hundreds of rows of sharp little teeth on its tongue. Most snails are herbivores (which means they like to eat plants).
Kauri snails inhabit moist areas of forest and native scrub. They live in areas of high soil fertility and abundant earthworms. Kauri snails are also highly mobile, and have been known to move 10 metres in 2 weeks.
The Maori name for the kauri snail is pupu rangi. Although it’s called the kauri snail, this snail doesn’t particularly like being around kauri trees because the ground is often too dry for it’s favourite food—the earthworm. Kauri snails can only be found in the far north of the North Island, in fact kauri snails only exist in New Zealand although they do have carnivorous cousins in other parts of the world.
These giants were once widespread in Northland before human settlement altered or destroyed their habitat Predation and they fell prey to introduced animals and birds. Many of them, including those in Puketi Forest, are now endangered or threatened, and inhabit a more restricted area of Northland and the islands offshore.
Did you know? Giant snails may live 20 years or more.