Kiwi Release Update
Feb 2007, By Margaret Willard
In May 2006, kiwi were heard calling in Rimutaka Forest Park for the
first time in hundreds of years.
“It was a magic moment when the first penetrating calls shattered the
silence,” says Annette Harvey, one of the volunteers camping out the
night of the birds’ release. “We heard the shrill ascending whistle of a
male first, answered by a hoarse guttural female, then another male – so
loud and so eerie it sent a shiver up my spine! We heard them frequently
throughout the night, and one kiwi was foraging right next to one of the
tents.”
The North Island brown kiwis’ apparent satisfaction with their new home
was gratifying to the more than 50 volunteers who had worked towards the
first release in the country planned and carried out entirely by an
independent trust. For the Wellington area it was also the first release
of North Island brown kiwi (Apteryx mantelli) and the first of any kiwi
into an unfenced area.
In uncontrolled areas up to 95% of kiwi chicks die before adulthood,
largely through predation by introduced mammals. The Rimutaka Forest
Park Trust’s expanding efforts at predator control, initiated by
contracting park caretaker John Rush around the park visitors’ centre
three years before, impressed then Department of Conservation Kiwi
Recovery Group leader Paul Jansen, who at the 2002 AGM of the Rimutaka
Forest Park Trust suggested the reintroduction of kiwi.
A new project group of the trust researched and compiled a proposal
seeking DOC approval for the release, as well as making new tracks and
making and deploying traps targeting stoats and rats in and around the
remote Turere Valley. Approval was announced at the October 2005 AGM,
opening the door to funding from the Bank of New Zealand Save the Kiwi
Trust. The group was told the hard work had only just begun.
While trapping continued and a group was trained in using tracking
equipment for monitoring the birds, Wainuiomata schools took part in a
competition to name the six kiwi to be flown from captive breeding
centres around the country during May. Each school is now regularly
updated on its bird’s progress. Two later arrivals, females Potiki and
Pounamu, named by members of Wainuiomata Marae, made up a total of five
males and three females.
Over 300 people were at the marae for the welcome and blessing of the
birds and the celebration of the first release, and around 100 stayed to
watch, via direct TV transmission from the Rimutakas, Paul Jansen and
volunteers take each bird from its special kiwi bag, check the
transmitter attached to its leg, and place it into a previously dug
burrow.
In the weeks following release the birds were weighed at intervals to
check how they were adapting to their new lifestyle, and all were
tracked via telemetry equipment every few days. Tracking continues on a
weekly basis.
Some of the birds’ wanderings have had trackers scratching their heads.
“A few have led us a merry dance,” says volunteer Melody McLaughlin. “A
couple have strayed a little out of the area - one into the Greater
Wellington’s recreation area - and we think others disappear into some
small gully, making it difficult for the aerials to pick up their
transmitter signal. Usually they’ve always reappeared fit and well.”
The exception was 18 year old Koniwi (named by Konini School) who, after
several weeks of attempts to locate him via tracking equipment and
ground searches, was found dead in his burrow in late December. A
reading from the transmitter attached to his leg indicated he had died
on 7 November 2006.
“We looked carefully, but couldn’t find any signs of predator attack,”
says Annette Harvey. “The average lifespan of kiwi in captivity is 20
years, so his death was probably age-related. He did well, considering
he was in captivity for all but his last few months, and seemed to have
adjusted well to life in the wild. Konini School will have the
opportunity to name one of the next arrivals.”
Waikiwianui’s transmitter signalled to trackers that he was incubating
his mate Manaia’s egg, and on checking his burrow one night while he was
out foraging, they found an egg about two metres into the burrow. “Even
if it proves not to be viable, it’s still encouraging that the birds are
settled enough to attempt to breed,” says Annette Harvey.
The possibility of dog attack is never far from the minds of the
volunteers. “We’ve eliminated nearly 300 stoats and four times as many
rats since the project began, so uncontrolled dogs are now our biggest
worry,” says Melody McLaughlin. “Kiwi scent is irresistible to dogs, no
matter how well trained, and the kiwi doesn’t have a breastplate like
other birds so can easily be crushed by a dog’s jaws. Once a dog starts
killing kiwi it will go after more.”
While most dog owners are aware of the need to control their animals in
the park and on the tracks, some ignore DOC signs requesting that they
be restrained, allowing their dogs the opportunity to find and attack a
defenceless kiwi.
Despite this threat, the trust is optimistic about the future of the
birds. Another two females and one male expected during 2007 will
contribute to the target of 10 pairs within 10 years, with recruitment
higher than the 20% needed for a self sustaining population. The
potential for additional pair bonds has the trust’s hopes high for the
winter breeding season.
“For this kind of project, the death of one bird in eight after seven
months, from what appears to be natural causes, indicates a very low
loss rate,” says Annette Harvey, who believes the area is ideal for a
kiwi population. “Looking around at the dense fern cover, huge rotten
logs, soft damp soil and plentiful holes, I feel that as long as any
dogs on nearby tracks are kept under control, this may well be close to
kiwi paradise.”
