Good news on Heaphy kiwi stats

23:58, Mar 18 2014

Trampers staying at Saxon Hut on the Heaphy Track should be able to hear the call of the great spotted kiwi at night, new research shows.

The latest chapter in a long term study of the great spotted kiwi on the Heaphy Track has shown that the bird population remains stable.

Led by Department of Conservation principal science advisor Hugh Robertson, the research focuses on an area of 250 hectares, just to the west of Saxon Hut, on the track.

The study is carried out every five years.

Mr Robertson said the kiwi population had remained stable over the past five years, with one territory amalgamating, and one splitting.

A territory was the area the bird's "own" which it generally did not stray from and averaged five to 10 hectares.


"They won't tolerate neighbours coming in and eating food. They define it with calling and by using scent marking. They use rivers and ridges and spurs to define it. Before we started our work in 1994 a study showed one bird killed another bird on the edge of a territory."

The main predators of kiwis, which are stoats, ferrets, cats and dogs, keep away from the area because it's very wet with an annual rainfall of 5.5 metres.

The kiwi are found using trained, muzzled dogs, and by imitating kiwi calls on a shepherd's whistle or amplified recordings.

Natasha Coad, who runs With a Nose for Conservation, which offers bird location services using dogs with partner James Fraser, said this year's research on the Heaphy was "really encouraging" with young adult birds coming into the breeding population.

"This means your recruitment into the population is really good," she said

"We do expect birds to die of old age. Once they hit adulthood it's hard to age them. James caught a chick, but it had a long way to go before it would be considered safe.

"But now it has a wing tag so we can check on it in five years," she said.

The couple train their setter dogs to show where kiwi are.

"They go rigid and indicate with their body where the bird is," she said.

She said the kiwis get more savvy and become more difficult to catch after they've been caught once.

The great spotted kiwi live up to 35 years and they have one chick per year, which may or may not survive into adulthood, she said.

"People should be able to hear kiwi calling at night. You're less likely to see them though, they live in the mountains," she said.

"It's a couple of weeks of intense research and then you can leave them alone for five years."

She said it was good to find the younger, unbanded birds, because it meant there had been "recruitment of birds".

"You're not having all the same old banded birds."

The research is mostly funded by the Bank of New Zealand Kiwis for Kiwi programme. DOC have been in charge of the study since 1994, though it began in 1987.