A pest-free kiwi sanctuary in the Rimutaka Forest Park will double in size, with hopes the number of birds there will flourish when pests are out of the picture.

Photo: RNZ / Adriana Weber

Conservation Minister Maggie Barry yesterday announced plans to double the size of the sanctuary near Wellington, from 3500 hectares to 7000ha.

The Department of Conservation - together with several other community organisations - will begin work to clear the extra 3500ha of stoats and other predators.

There were already over 100 kiwi in the park, and more than half of them hatched there.

Ms Barry said that number would flourish even further when pests were out of the picture.

She said she wanted to see the kiwi population increase by 2 percent each year.

"The ultimate aim is to have about 100,000 kiwi across New Zealand, increasing the population of the eight different breeds so that throughout the country, in the wild, people will wake up in the night and hear the sound of the kiwi. They will have to move them along in their gardens, I want them to be a nuisance in people's backyards."

She said 1200 Goodnature resetting traps would be laid in the area as part of the initiative.

The traps can reset up to 24 times before they need to be reloaded.

Photo: Supplied: Scimex

Goodnature co-founder and director Robbie van Dam said he expected the traps to kill tens of thousands of stoats during the programme.

He said it also would not take long to get the traps up and running, and for people to see the results.

"The thing with these things is that 1200 traps you can probably do in a couple of days. A single person can set about 60 or 70 per day, so once we've got our network in place and once we've planned out the routes that we're going to take it'll only take a few days to get up and running."

Rimataka Forest Park Trust president Geoff Cameron was welcoming the rollout of the traps.

"Anything that we can do to increase the chances of the kiwi chicks surviving and getting up to a kilo in weight so they can fight off any of the other predators is good news for us," he said.

It would also help ease the workload of the trust's 140 volunteers, he said.

"Our trappers who work with other traps will be absolutely delighted because it means there's not so much pressure on them, not so much pressure on the other traps, and they will have easier rounds when they go about their weekend's work."

Mr Cameron said eventually he wants to see all of 22,000ha of the Rimutaka Forest Park predator free and safe for kiwi.