One of New Zealand’s rarest songbirds has staged a remarkable comeback in the hills south-east of Auckland, with a new count confirming the Hunua Ranges now hold the largest mainland population of North Island kōkako in the country.
Auckland Council’s latest census recorded 418 breeding pairs of kōkako across the ranges, a blue-grey native songbird famous for the slow, organ-like call that drifts through the forest at dawn. The new tally is a 61 percent jump on the previous count in 2022, and it caps a recovery that has taken the better part of three decades.
It is a long way back from the brink. Researchers estimate around 500 kōkako lived in the Hunua Ranges in the 1950s, but by the late 1960s the population had crashed to roughly 50 birds. By 1994, surveys could find just 25 birds left in the ranges, with only a single confirmed breeding pair. From that thread of survivors, the forest now echoes with hundreds of pairs.
Principal ranger Miranda Bennett, who oversees the recovery work, said the run of strong breeding seasons was the clearest sign the population was now standing on its own feet. “It tells us breeding has been successful over multiple seasons and that these youngsters are surviving long enough to join the breeding population themselves,” she told RNZ.
That last point matters more than it might sound. A young kōkako does not simply hatch and start breeding. It typically takes around two years for a fledgling to find and hold its own patch of forest and enter the breeding population, so a record count of pairs reflects breeding success stretching back several seasons rather than one good summer.
The turnaround rests on an unglamorous foundation of pest control. Kōkako are poor flyers that nest and feed low in the canopy, which leaves their eggs, chicks and even sitting females dangerously exposed to introduced predators. Possums raid nests and strip the trees the birds rely on for food, while ship rats take eggs and young. Knock those numbers down and the birds do the rest themselves.
Auckland Council’s most recent operation drove predator numbers to some of the lowest levels ever recorded in the ranges. Possum monitoring, measured as a residual trap catch, fell from 2.2 percent before the work to just 0.16 percent afterwards. Rat tracking, which had sat at between 90 and 100 percent before control, dropped to 1.34 percent. The council had set itself targets of under 2 percent for possums and under 3 percent for rats, and both were comfortably beaten.
The work was done by aerially applying the poison 1080 across 19,885 hectares of forest, backed up by another 130 hectares of ground-based control, with the operation finished by the end of October 2025 so the bush was as safe as possible heading into the summer breeding season. Bennett said the result reflected careful planning. “We aimed for under two per cent RTC for possums and under three per cent RTI for rats, and both were comfortably achieved,” she said in an Auckland Council update.
The kōkako are not the only winners. The same predator control protects other native birds that share the forest, including the kererū wood pigeon and the boisterous kākā, along with insects, lizards and the plants that feed them all. Conservationists often treat kōkako as a barometer for the wider health of a forest, because a bird this vulnerable only thrives when the whole system around it is working.
Auckland councillor Richard Hills, who chairs the council’s policy, planning and development committee, said the milestone showed what sustained effort could deliver. “This work shows what is possible when science, experience and long-term commitment come together,” he said. He was also quick to spread the credit, thanking “mana whenua, every volunteer, ranger, council staff members, and contractor who has worked so hard to turn their vision, passion and work into this incredible comeback.”
That breadth of involvement is part of the story. The recovery has leaned on volunteers walking transects to count singing birds, contractors flying control lines, council rangers and the iwi who hold mana whenua over the ranges, working together across decades rather than electoral cycles. The payoff is a population that no longer feels fragile.
The Hunua result also carries weight beyond Auckland. North Island kōkako were once widespread across the upper half of the country, but forest clearance and introduced predators pushed them into a scatter of isolated pockets. Strongholds like the Hunua Ranges become reservoirs of birds that can, in time, help repopulate other restored forests. A site that once held a single breeding pair is now one of the most important kōkako populations anywhere.
For anyone walking the ranges this winter, the proof is in the sound. The kōkako’s call carries a long way through still forest air, a deep and unhurried series of notes that early settlers and Māori alike found unforgettable. Thirty years ago it had almost fallen silent in these hills. Today it is, by the council’s count, the busiest kōkako chorus on the New Zealand mainland.
Have you heard a kōkako in the Hunua Ranges or anywhere else around the country? Tell us about it in the comments below.
This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job 🙂
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