One of New Zealand's most threatened bird species will have a better chance at breeding this year following the completion of an aerial predator control operation last week.
The Department of Conservation (DOC) and Zero Invasive Predators (ZIP) successfully applied biodegradable 1080 bait across part of Rakiura National Park as an important measure to save pukunui/southern New Zealand dotterel from the brink of extinction.
DOC Southern South Island Operations Director Aaron Fleming says the aim is to give the birds a lifeline by heavily reducing feral cats, rats and possums.
"With just 105 birds remaining, pukunui are literally on the brink of extinction. The population has declined from 176 since 2020, largely due to predation by feral cats. In the 2023 season alone at least 41 adult birds died.
"Over the years, our team have worked extremely hard trapping, hunting and using bait stations to control predators but with pukunui numbers continuing to decline, it was clear we needed to take a different approach – before it was too late," says Aaron.
Pukunui were once widespread across the South Island and Rakiura is their last refuge. Intensive management saw a slight lift in the population this year from 101 to 105, but to secure their long-term future, introduced predators need to be controlled over a larger area.
The safest and most effective way to control predators over large, remote areas is to use bait pellets containing 1080, which are distributed from helicopters along predetermined and monitored flight paths. The bait targets rodents and possums, with feral cats controlled as they feed on the poisoned carcasses.
Bait was applied over about 40,000 hectares of Rakiura National Park, covering the large home range of feral cats. ZIP also delivered a small-scale eradication trial across 6,500 hectares testing tools and techniques for the Predator Free Rakiura project.
This was the first time 1080 cereal bait has been applied aerially on the island to protect pukunui, and DOC is optimistic for the breeding season this spring and summer. The next pukunui flock count will be in Autumn next year.
"For years the annual flock count for pukunui has felt like documenting the demise of a species in real time, which has been devasting for those who work so hard to protect them. Once they're gone from here, they're gone for good," says Aaron.
"A predator free Rakiura is the long-term solution for pukunui and other vulnerable native species, but urgent action was desperately needed, or it could have been too late for this unique New Zealand species."
Hundreds of remote trail cameras are set out in the operational area to measure the abundance of predators before and after the operation.
Warning signs are in place at access points to the predator control area. 1080 is poisonous to humans, domestic and game animals. Hunters are warned not to eat animals from within the treatment area and two-kilometre buffer zone until the warning signs have been removed.
The aerial operation was largely funded by $3 million from the International Visitor Conservation and Tourism Levy. DOC is grateful for support from the New Zealand Nature Fund, donors and others which contributes to the ground-based predator control and management of pukunui.
