Updated expert perspective: Professors Peter Dearden and Charles Eason

"A few months ago, we provided our views on the state of predator control in New Zealand – what are the challenges, and what are the needed technologies?

We stated boldly that a problem arises from boundaries – we can kill pests with current technologies, as long as we have strong boundaries like predator-proof fences to stop invasions, and in areas without these (eg, in rough terrain such as Fiordland) we need new technologies.

We also commented that committed professionals with detection technologies, new delivery systems for existing toxins, artificial intelligence, drones, and resetting kill-traps will enable landscape-scale control of predators, including at low densities. Cleverly adapting and repurposing existing compounds with toxic potential, new tools, and emerging technologies, combined with new landscape strategies, can lead to significant advances in control.

Since we wrote, the team at Zero Invasive Predators (ZIP) invited us to visit a project named Te Manahuna Aoraki in the Mackenzie Country. They wanted to show us what they were achieving in some of the roughest country in the world. A switch in strategy has enabled them to make huge progress in controlling rats, possums, stoats, and even rabbits.

ZIP takes the view that the best way to enact pest control is not suppression but elimination. The team’s strategy is to expend the energy to remove pests completely from an area within 'good' natural boundaries – mountains, rivers, and sea – supplemented with fences. They have developed new technologies to enable this eradication: AI-driven remote-reporting thermal cameras, new baits (mayonnaise), and stations that automatically dispense bait and poison. All these technologies enable eradication, but their focus on eradication appears to be the key switch.

ZIP has cleared rats, possums, and stoats from a 100,000-hectare area (larger than the city of Berlin) of West Coast farmland, forest, and townships. They have cleared rats and possums from an 30,000-hectare block of the Mackenzie High Country, including stations, defence land, and national park, and are now moving to do the same to the area around Aoraki, the Main Divide, and Mt Cook Village. They have even eradicated the ubiquitous rabbits from 4,000 hectares of the Mackenzie Country.

The block they have cleared in Mount Cook Aoraki National Park includes some of our most mountainous land, at the highest elevation, and is an incredible demonstration that the tools and technologies which ZIP has developed can work in our most challenging landscapes.

So how do they cope with incursion? Well, relying on “soft” natural borders means that ongoing incursions into some of these areas will be inevitable, but some valleys in the West Coast haven’t seen a possum, stoat, or rat since 2019.

Kakariki are breeding at higher numbers; kea are recovering; forests are blooming; and more kiwi chicks are surviving than ever.

Ongoing monitoring will be needed to convince the sceptics, and then, to stop the ongoing incursion, ZIP just needs to roll this out for all the rest of the South Island.

The dedication of the staff and their communications to local communities are of the highest standard. We think the key change is their strategic ambition – to focus on eradication. By not accepting the presence of any predators, ZIP has been driven to find new ways to implement pest control – ways that really do enable the possibility of a Predator Free Aotearoa."

Published March 2026

Professor Peter Dearden is a geneticist interested in evolution and development, animal genomics, and honeybee population management. He is the head of Otago University’s biochemistry department and co-director of Genomics Aotearoa. He has investigated the use of genetic modification technology and its possible contribution to the Predator Free 2050 goal. The Society awarded him the Callaghan Medal for science communication.

Professor Charles Eason CNZM CRSNZ FRSNZ, from Lincoln University, has a had a career in toxicology and pharmacology, initially in the development and registration of medicines, working within multinationals in Europe and then on pest control products in New Zealand. He specialised in the challenging area of vertebrate pesticide toxicology and product registrations and is internationally recognised for his work on the safety and effectiveness of different toxins.