Kiwi deaths a setback for Pukaha restoration efforts

Work towards establishing a self-sustaining population of kiwi at Pukaha Mount Bruce has suffered a set-back with four of the birds in the forest falling victim to a ferret attack. Among them were three of the 30 North Island Brown Kiwi transferred from Hauturu/ Little Barrier Island to the forest in May. Signals from transmitters attached to the birds led to discovery of the deaths during last week.

When all four birds were found to have injuries consistent with a mustelid attack, extra traps targeting ferrets were deployed in the area where the kiwi were found. A Massey University pathology report concurred that the culprit was likely to be a ferret. The trapping effort paid off when a large male ferret was caught in the vicinity.

Pukaha Mount Bruce Board chair Bob Francis says while the deaths were sad they highlighted the challenges of returning kiwi to the wild. Despite the setback, the Board was determined to continue the forest restoration efforts.

“Predators are common in all forest areas and while we will have losses, we will continue to make significant gains as well. That’s why it’s important to build a population large enough to absorb occasional losses,” Mr Francis says.

Department of Conservation Wairarapa Area Manager Chris Lester says the department continued to have confidence in its pest control programme, “But the reality of managing kiwi and other species such as kokako and kaka in un-fenced reserves is that these predation events are inevitable. With the generous ongoing support of the community and the dedicated effort of staff and volunteers we are making good progress in re-establishing species previously lost from the Pukaha Forest.”

The 30 translocated kiwi had been closely monitored since their release and they appeared to have settled well. They had been establishing territories and several appeared to have found mates in readiness for the breeding season.Department of Conservation Programme Manager Biodiversity Bruce Vander Lee says the 30 translocated kiwi were all fitted with transmitters.

“This enables us to keep tabs on them without catching or disturbing them, which is important in the early stages while they’re settling into their new home,” he says.

A plan to re-capture all of the kiwi for their first health check had been under way for a week and Mr Vander Lee says “the birds we’d captured had made impressive weight gains and were in extremely good condition”.

When mortality signals were received from several birds, the health checks had to be suspended while staff recovered the dead kiwi and hunted for the culprit responsible.

The recent addition of the 30 kiwi from Hauturu/ Little Barrier Island is part of a long-term plan to build a population that will be capable of withstanding losses from time to time.

Additional facts about pest control at Pukaha Mount Bruce

• Manages 130kms of trap lines

• Manages over 1000 bait stations for rats and possums

• Manages over 500 traps for rats, ferrets, stoats and weasels.

• Pest control is the most expensive thing we do

Thirty NI Brown Kiwi were transferred from Hauturu/ Little Barrier Island on 7 May 2010. The birds were flown by NZRAF Hercules from Auckland to Masterton where they were welcomed by many well wishers who had turned out to celebrate their arrival.

The arrival of the kiwi coincided with the completion of a community-wide campaign to raise $300,000 to support the ongoing restoration of the Pukaha Mount Bruce forest, including pest control. Dubbed ‘Flight of the Kiwi’ the three-month campaign involved a series of fundraising events and educational programmes throughout the Wairarapa and Tararua regions.

The funds will also assist with the kiwi translocation from Little Barrier Island to Pukaha and a $1.5 million upgrade of the kiwi nocturnal house and visitor facilities at the centre. This translocation would go some way to ensuring that the kiwi population at Pukaha Mount Bruce continues to grow and becomes self-sustaining.

Prior the LBI translocation, nineteen captive-bred kiwi had been released into the Pukaha Forest since December 2003. They first bred successfully in 2005, kick-starting a BNZ Operation Nest Egg™ programme for kiwi at Pukaha Mount Bruce. So far nine eggs have been collected from the Pukaha forest and hatched in captivity, with the resulting chicks being reared in captivity for a period of time, before being released back into the forest.

The successfully reared juvenile kiwi were produced by three known breeding pairs, Seven were sired by the same male (Mr Kiwi). Five adult kiwi, about 20 percent of the existing population, were killed by a large ferret in 2008. The ferret was trapped and killed soon after the event. Following this event Horizons RC and GWRC increased the number of traps in the area where the ferret was believed to have entered the reserve.

The population of kiwi in the Pukaha forest increased to 54 birds with the LBI translocation. A further two captive reared birds from the Westshore Wildlife Reserve were released on 16 July 2010.

Radio transmitters are fitted to the kiwi to allow them to be tracked and monitored with minimal intervention.

Pest control work is an ongoing necessity to ensure the long-term survival of the kiwi, kokako and kaka in the reserve. The pest control regime uses pesticides and a range of traps that are designed to target pest species including ferrets, stoats, rats and feral cats.

Find out more about Pukaha Mount Bruce: www.pukaha.org.nz  Find out more about the BNZ Operation Nest Egg™ programme on the BNZ Save The Kiwi website:
www.savethekiwi.org.nz/bnz-save-the-kiwi/bnz-operation-nest-egg.html

BNZ Save the Kiwi Trust was established in November 2002 by Bank of New Zealand and the Department of Conservation, building on a sponsorship relationship that started in 1991. BNZ Save the Kiwi Trust is responsible for public awareness and education, fundraising, sponsorship and grant allocations for kiwi recovery nationally. In 2008 alone, more than $1 million was allocated to community and DOC kiwi projects. This money came from Bank of New Zealand, its staff, customers and supporters of BNZ Save the Kiwi Trust.

BNZ Operation Nest Egg™ is a powerful tool to reverse the decline of key kiwi populations. Eggs and chicks are harvested from nests to save them from stoats and cats. The young kiwi are returned to the wild when they weigh about 1kg, big enough to fight off these predators. More than 1000 kiwi chicks have been returned to the wild since the programme began in 1994, with captive facilities and hundreds of field workers from DOC and community groups throughout the country contributing to its success. The BNZ Operation Nest Egg™ egg harvesting>chick rearing>return to the wild technique was developed for kiwi through research funded solely by Bank of New Zealand and is now also used in other species recovery programmes.
www.savethekiwi.org.nz