hunts worms in the south island duff

Size
Shell: 6–10 cm
Lifespan
10–20 years
Diet
Carnivorous - feeds exclusively on earthworms and native snails. Uses its large, muscular foot to engulf prey whole. One of the world's largest land snails, found only in New Zealand. Many subspecies are restricted to single mountain ranges. Threatened by introduced predators including thrushes, pigs, rats, and possums which crush their shells.
Habitat
The cool, moist, high-altitude beech forests and tussock grasslands, primarily in the top of the South Island and parts of the Horowhenua. They live in the deep, damp leaf litter - the "duff" - where the humidity is high and the worms are plentiful.
Range
New Zealand - found in high-altitude beech forests and tussock grasslands of the top of the South Island and parts of the Horowhenua. Most common in the Nelson region, North-West Nelson, and the Horowhenua. Different subspecies are restricted to specific mountain ranges.
Endemism
Endemic
Main Threats
Predation by introduced thrushes, pigs, rats, and possums is the primary threat. Also threatened by habitat loss from forest clearance, fire, and browsing by deer and goats which damages their habitat. Classified as Nationally Critical, with some subspecies having fewer than 100 individuals remaining.
Population
These slow-moving giants are a easy target for introduced thrushes, pigs, rats, and possums, who crush their shells like walnuts. With some subspecies restricted to single mountain ranges, a single predator incursion can wipe out an entire evolutionary lineage.
Conservation Status
Nationally Critical
Human Risk
harmless
Handling Note
protected native land snail, do not disturb habitat
Conservation Note
Endemic land snail restricted to specific locations; threatened by habitat loss and predation.
Te Ao Māori
To Māori, the Pūpū rangi (literally "snail of the heavens") is a creature of the misty, high-altitude realms. Their shells, often intricately patterned with concentric rings of gold, brown, and red, were admired for their beauty, resembling the weaving patterns of a fine cloak. They are seen as the quiet, slow-moving spirits of the ngahere (forest), existing in a world that is perpetually damp and ancient. Because they are so long-lived - potentially reaching 20 years or more - they represent a link to the ancestral time, surviving in the "cloud forests" where the veil between worlds is thin.
It is not a garden pest. If you think all snails are slow, garden-variety pests that ruin your hostas, the Powelliphanta is here to correct your worldview with terrifying efficiency. This is a "super-snail". It can grow to the size of a man's fist, and its shell is a work of art - glossy, heavy, and patterned like a high-end Italian silk tie. But do not let the aesthetics fool you; this is a highly specialised, nocturnal predator. It does not eat leaves; it eats meat. Specifically, it hunts giant earthworms that can be up to a metre long. The hunting technique of a Powelliphanta is pure nightmare fuel for an earthworm. It tracks its prey by scent through the damp leaf litter. When it finds a worm, it does not nibble; it strikes. It uses its radula - a tongue covered in thousands of microscopic, razor-sharp teeth - to grab the worm and literally suck it up like a piece of overcooked spaghetti. Because the worm is often much longer than the snail, the Powelliphanta has to fold its prey as it swallows, a process that can take several minutes of grim, muscular effort. It is the apex predator of the "micro-jungle" on the forest floor. The Powelliphanta is also a biological marvel of the "long game". They are hermaphrodites, but they still need a partner to mate. They lay about five to ten large, hard-shelled eggs a year - eggs that look remarkably like those of a small bird. These eggs take a year to hatch, and the young snails take several years to reach maturity. This slow-motion life cycle worked perfectly for millions of years in a land with no mammals, but today it makes them incredibly vulnerable. A single thrush can smash dozens of shells against an "anvil" stone in a morning, and a wandering pig can vacuum up an entire local population in a single forage. Conservationists now go to extraordinary lengths to save them, including "snail-herding" during mining operations and building massive, predator-proof fences around their forest strongholds. In 2011, a refrigeration failure at a DOC facility famously led to the accidental "cooking" of 800 of these rare snails - a national tragedy that highlighted just how precarious their grip on existence is. They are the beautiful, carnivorous giants of our dampest forests, reminding us that in New Zealand, even the snails have a bit of "monster" in them.