The first baseline kiwi population survey ever conducted in the Forest Lifeforce Restoration Trust’s sanctuary in the Maungataniwha Native Forest has yielded an average call rate of 2.6 an hour. This is high by Hawke’s Bay standards and compares favourably with rates of 0.5 an hour just across the Waiau River in unmanaged parts of Te Urewera National Park.
National kiwi survey protocols were used to conduct the research. Seven sites were surveyed during the first two hours of darkness for three consecutive nights in May, with two people staffing each site.
"The Trust team members behind the Maungataniwha Kiwi Programme, Barry Crene and Pete Shaw, should be very pleased with that result," said Trustee Dr John McLennan who conducted the survey and interpreted its results.
Dr McLennan was instrumental in establishing the kiwi conservation programme on the Puketukutuku Peninsula on Lake Waikaremoana, now managed by Tuhoe, where kiwi are now approaching pre-human levels of abundance with survey readings of as many as 30 calls an hour.
The Maungataniwha Kiwi Project is part of Kiwi for kiwis’ Operation Nest Egg and is fast carving out a name for itself as one of the most prolific and successful kiwi conservation initiatives in the country. Since its inception in 2006 it has harvested about 360 eggs and seen 200 chicks released back into the wild, about 160 of which have been released back into the Maungataniwha Native Forest.
Fully-fledged chicks released back into the forest as part of the project have an approximately 70 percent chance of survival. This survival rate contrasts starkly with the five percent chance that kiwi have of making it to adulthood if hatched in the bush and left unprotected against predators.
Population modelling suggests around 200 kiwi needed to be released back into Maungataniwha to make the population there secure for the next 30 years.
Despite the survey findings Maungataniwha remains well below its kiwi carrying capacity, Dr McLennan said. "We reckon our sanctuary area is home to about one-sixth of the number of kiwi it could potentially support."
Hawke’s Bay unmanaged kiwi population densities are usually lower than other places on the North Island. In Northland call rates of six to 10 an hour are common.
Dr McLennan would like the Forest Lifeforce Restoration Trust to conduct kiwi population surveys every couple of years.
"I’m thrilled with this initial set of results because it tells us that the work that has gone into kiwi to date at Maungataniwha has made a substantial difference," he said.
In addition to the Maungataniwha Kiwi Project the Trust runs a series of native flora and fauna regeneration projects. These include a drive to increase the wild-grown population of Kakabeak (Clianthus maximus), an extremely rare type of shrub, and the re-establishment of native plants and forest on 4,000 hectares currently, or until recently, under pine.