Volunteers help protect the bird that gives us our name
Two critically endangered South Island kiwi populations are increasing, but nationally the numbers of the iconic bird are declining.
In the South Island, there are three kiwi species, and four geographically and genetically distinct forms of one of those. They are known as "taxa", instead of breeds, as they are not scientifically described.
Of those taxa, the Haast tokoeka and the rowi are the most at risk due to their low populations and distribution.
The Department of Conservation has focused mainly on managing those two breeds, but the remaining types - Northern Fiordland tokoeka, Southern Fiordland tokoeka, Stewart Island tokoeka and the great spotted kiwi - are all threatened.
The Haast tokoeka's chances of survival have increased markedly in the past decade, thanks to programmes involving DOC, iwi and community groups.
Some of these "nationally critical" birds are found around Haast, others have been transferred to a number of predator-free island sanctuaries. They number about 400.
In 1996, they totalled 225.
Likewise, the rowi has increased from a low of 150 birds in 1996 to 300 in 2008, to 400 this year.
Under DOC's recovery plan, the aim is to increase both species' numbers to 600 by 2018.
However, DOC team leader biodiversity Neil Freer said it was because of "intensive management" the two species population had increased.
"It's [the population] not safe by any stretch of the imagination," he said.
If management had not happened then the two species would be declining at the same rate as total kiwi numbers, about 2 per cent per annum.
Nationally, the population of kiwi was 72,600 in 2008 and this is expected to drop to 63,500 by 2018.
Freer said programmes, such as BNZ Operation Nest Egg, were key to increasing the numbers, especially of rarer taxa.
This programme involves monitoring adult pairs then "rescuing" eggs from the nests.
The eggs are incubated at breeding centres before being taken to a predator-free island for up to 12 months or until they reach a "predator safe weight" of about 1200 grams and they are released into the wild.
So far this year 26 Haast tokoeka eggs have been rescued, with more expected to be found in the next few weeks.
DOC community technical adviser for South Island kiwi sanctuaries Tim Shaw said community involvement was vital.
"It's certainly a job that is larger than the department - if we're going to be effective on all of these taxas then we need to get the community involved."
Last year, seven young Haast tokoeka were put on Pomoana Island in Lake Manapouri after more than 240 volunteers from the Pomoana Island Charitable Trust put in 7000 hours to rid that island of predators.
Shaw said they were always "refining and improving" their kiwi management techniques.
He was confident none of the taxa would become extinct, but expected some to decline in numbers as they focused more intensively on bringing the more threatened birds to sustainable levels.
- © Fairfax NZ News