Bringing back nature to Nelson

Alison Ballance visits the Brook Waimārama sanctuary, and discovers that the old saying "many hands make light work" is particularly true when it comes to community conservation. A relatively new fenced sanctuary, the Brook Waimārama team is now at the exciting stage of bringing native wildlife back into the area, including orange-fronted parakeets - kākāriki karaka - and giant land snails.

Giant carnivorous land snails. New Zealand's rarest parakeets. And noisy tieke or South Island saddlebacks.

All three species are at risk from introduced predators - and all have recently been given a safe new home on the outskirts of Nelson, inside the Brook Waimārama fenced sanctuary.

The 690-hectare forested valley was once the water supply catchment for Nelson. These days it satisfies a different kind of thirst - for nature and community conservation.

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The Brook Waimārama sanctuary is surrounded by a 14.4 kilometre-long pest-proof fence that was constructed in 2016. In 2017, all introduced animals within the fence were removed; this included predators such as rats, stoats, possums and pigs, and browsing mammals such as goats and deer. In 2019 the sanctuary was declared pest-free. Mice have subsequently reinvaded, as they have in other fenced sanctuaries, and are a constant presence.

Occasionally, rats and weasels have managed to get back in but sanctuary staff and volunteers respond quickly, setting up networks of kill traps to catch the invaders.

Giant carnivorous land snails

In July 2022, 30 large land snails were released in the sanctuary.

The Powelliphanta hochstetteri consobrina snails were collected from two sites nearby, one a pine forest and the other native forest. Ten more snails from another site will be translocated later.

This is the first official translocation of a Powelliphanta species, and is possible because the subspecies is absent from the sanctuary but is clearly within its natural range.

This subspecies grows to about 5 centimetres across, and like all Powelliphanta snails is slow-growing and long-lived.

Powelliphanta snails hunt earthworms, which they slurp like spaghetti.

The snails will be left undisturbed for five years, when a search will be carried out to see if any small snails can be found, which will indicate that breeding has taken place.

Orange-fronted parakeets / kākāriki karaka

Orange-fronted parakeets or kākāriki karaka are New Zealand's rarest parakeet, with just a few hundred birds in the wild in North Canterbury…

Go to this episode on rnz.co.nz for more details