Last week, seven kakapo* were translocated to Little Barrier island in the North island as part of an effort to provide greater population security for this critically-endangered bird.
Previously, there were only two kakapo breeding sites for our 126 kakapo – Codfish and Anchor islands.
Southland programme manager, Deidre Vercoe says the two Southland islands were reaching carrying capacity which could hinder breeding efforts in future years.
“Little Barrier is a 3,000 hectare island, so each bird will have an extensive foraging ground,” says Vercoe.
A catastrophic natural event or an epidemic could seriously threaten the survival of this species, so spreading the birds across three varying habitats and geographic locations improved the chances of the kakapo’s long-term survival.
Several new homes were considered by the Department of Conservation, however Little Barrier is one of the only islands that is a safe distance from the mainland, so no stoats, weasels or rats can swim over to predate these critically-endangered birds.
Unlike the operation in the south, the birds on Little Barrier island will not be intensively managed.
“We started looking for sites where they can manage by themselves because some day in the future there may not be the money to manage them so intensively,” she says.
DOC spends around $800,000 each year on the Kakapo Recovery Programme.
This pays for regular health checks, supplementary feeding, artificial incubation, research (artificial insemination, genetic studies, and supplementary feeding trials) and developing technology.
“They won’t receive supplementary feeding during the breeding season, nor heat-pads for their nests. Of course if they have a chick, we’ll monitor them a little more closely.”
“Over the years we’ve become good to knowing when a chick is going to die, so at that stage we’d step in to ensure its survival.”
Kakapo were last seen in the North island 13 years ago on Little Barrier island and during this time they raised several chicks with the support of supplementary feeding.
In 1999, this small population was removed from the island so rats could be eradicated and a decision was made to transfer the remaining North island kakapo to Codfish island.
“Monitoring on the island was difficult because staff needed to cover a vast area of steep terrain. It’s so a tough to traverse, we coined the phrase ‘Little Barrier knee', ” Vercoe says.
Kakapo typically breed every two to three years, so it is hoped that within the next 6 – 10 years the team will know whether this population is able to raise its chicks independently.
The new arrival’s movements and mating habits will be monitored by a remote aerial tracking system that can detect when kakapo are nesting, or even mating.
“ The kakapo will be fitted with transmitters that tell us whether they are living or dead; whether they’re nesting, if they mating and who they’re mating with,” she says.
On Codfish and Anchor islands, the breeding success of the kakapo is primarily determined by the abundance of rimu fruit.
By placing them on an island with only a few stands of rimu, DOC staff may also be able to determine alternative species that trigger breeding, such as kauri.
“Once kakapo were found throughout the country and we suspect their breeding responds to other masting species such as beech, kauri and pine."
Since the start of the kakapo recovery programme in 1990, the size of the population has almost doubled, and Vercoe says that if it continues to grow, they’ll look at relocating kakapo on other offshore islands.
“No other islands have a body of water large enough to ensure pests can’t reinvade the island. Another site being considered is Resolution island but that will have to be managed in perpetuity for the risk of predators re-invading.”
Forest & Bird is a partner of the Kakapo recovery programme, along with the Department of Conservation and New Zealand Aluminium Smelters.
* Eight kakapo were destined for Little Barrier however one kakapo was taken to Auckland Zoo for medical care after she was found to have an inflamed cloaca when captured on Codfish. It is hoped that she will be transferred to the island in the coming weeks.