Reintroducing kiwi to Wellington has been a wild, stoat-busting success

Veronika Meduna

Science & environment writer·New Zealand Listener·

12 Sep, 2026 07:04 PM4 mins to read

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Young Kiwi chicks were deemed big and heavy enough to fend off stoats and  their ankle transmitters were removed. Photo / Caleb Smith/Capital Kiwi Project

Four years ago, a matriarch arrived with a small entourage for a special homecoming in the hills southwest of Wellington. At nearly 50, Anahera had already produced dozens of offspring and had come to herald the return of wild kiwi to their ancestral lands, some 150 years after they
had become locally extinct.

The flock of 11 kiwi-nui (North Island brown kiwi) became the first of a new wild population that now numbers 250 and growing. Recently, the youngest chicks were deemed big and heavy enough to fend off a stoat and their ankle transmitters were removed. All birds are now roaming free.

Taking the last transmitters off was bittersweet, and the team had a few “onion-in-my-eye” moments, says Paul Ward, the founder of the Capital Kiwi Project. But the monitoring data show nine in 10 chicks had lived to become stoat-proof – “statistics beyond our wildest expectations”.

This rewilding milestone was a decade in the making. Before any kiwi could be released, the project team, iwi, locals, farmers and landowners put countless weeks into clearing predators, with 5300 mustelid traps laid across an area larger than Abel Tasman National Park, spanning from farmland to the capital’s suburbs.

Then, before the team could approach iwi and sanctuaries willing to gift kiwi for release, they had to show that the trap network could keep stoats at sufficiently low numbers. Back then, there were many unknowns, Ward says. Would the habitat be suitable? Would the birds find enough food? Would they breed and the chicks grow big enough?

In areas without predator control, 95% of kiwi chicks fail to reach 1.2kg, the crucial fighting weight to stand up to a stoat. But monitoring of the birds reintroduced into the Mākara hills shows they are thriving. “It has provided us with the confidence that most of those birds will live long lives out on those hills,” Ward says.

For a kiwi population to grow, at least 20% of chicks have to survive. The project was set a target of 30% chick survival in its Department of Conservation permit. Ward says the team was confident it could do better than that, but it nevertheless meant potentially losing quite a few young birds. “Nature is red in tooth and claw, particularly in island ecosystems like Aotearoa’s. Even delivering a successful project involves coping with death and loss.”

Capital Kiwi’s very first chick from the first breeding season did indeed die. But since then, the team lost only one more in three years. “We’re sitting on well over 90% chick survivorship.”

The project shows some threatened species can be reintroduced into modified productive landscapes without fences and close to where people live. “For critically endangered species, predator-free sanctuaries and islands remain critical lifeboats, but some species are actually able to survive and thrive with intensive predator control rather than elimination,” Ward says.

Many of the birds that returned to the fringes of Wellington came from confined spaces, including kiwi houses. Out on the hills, they can roam further in search of food, and the team found chicks were growing faster than expected.

But achieving the project’s main goal of restoring kiwi to the wild on their own terms and “letting them go from our intensive care” doesn’t mean the job is done. The trap network has to be maintained and the birds will continue to be monitored, albeit through non-invasive acoustic methods and reports from locals. Given kiwi have now proved the concept, the team is already contemplating possibilities for restoring other taonga species into the landscape.

And as for Anahera, now that all transmitters are gone, there’s no way of knowing where she is. Ward thinks she’s alive and kicking and may yet produce more chicks. One of her offspring, Ngārangi, was one of the first homegrown wild kiwi to make it to stoat-proof weight. “He’ll likely outlive all of the people who were out there removing his transmitter.”

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