Three-yearly 1080 drop in Whanganui back-country

The famous Bridge to Nowhere in the Mangapurua Valley gets hundreds of visitors. Photo / File

The native birdlife in the Mangapurua Valley is some of the best one goat hunter contracted to work there has ever seen - and it's about to get its regular dollop of protection.

"This area has some of the highest populations of birdlife I have seen anywhere in New Zealand over my hunting career," the hunter told Conservation Department (DOC) staff.

The Mangapurua is part of Kia Whārite, 180,000ha intensively managed to protect biodiversity, and goats are culled on 40,000ha of it. It's headed for another aerial drop of 1080 poison baits to kill possums, rats and stoats some time soon.

Kia Whārite is a joint project of DOC, private landowners and the Horizons Regional Council. It takes in parts of Whanganui National Park where there are a lot of kiwi - and also a lot of canoeists, trampers, walkers and mountain bikers.

The Kia Whārite area and 32,500ha of the park will have 1080 poison baits dropped over them as soon as there is a good stretch of fine weather. Local people have been consulted and warned and there has been a public notice in the Chronicle.

Technology allows the sowing to be done very precisely, DOC staff say. The first helicopter flyover will drop 2cm-long cylindrical cereal baits, at a rate of 500g per hectare. They will be eaten by possums and rats.

In the next flyover the baits will be dyed green and contain sodium fluoroacetate (1080), at the rate of 0.75g of poison per hectare.

Each drop needs three fine nights after it, to get as many animals as possible eating dry bait. Stoats then eat the other poisoned animals, and die as well.

After previous operations in the Mangapurua very few stoats and rats have been left alive.

This poisoning has been done about every three years since 1995, with the last batch in October 2015. It started after staff noticed severe dieback from possum browsing in kamahi and rātā trees.

Maintaining the trees' health provides food for native birds, lizards and insects. And keeping stoat numbers down allows young kiwi to grow up - 60 per cent are otherwise killed and the kiwi population would decline 3-5 per cent a year without predator control.

CARE AROUND 1080 DROPS
+ Don't touch baits
+ Watch children constantly
+ Don't eat animals from anywhere within 2km of the treated area
+ Baits are deadly to dogs
+ So are poisoned animals, until they have completely rotted
+ If poisoning, contact doctor, hospital or National Poisons Centre - 0800 764 766
+ Report vandalism of any warning signs