Predator eradication projects
There have already been several successful predator eradication projects around the world and in New Zealand. Looking at how these projects navigated different challenges helps inform how we develop our project. It also shows that it can be done!
What makes an eradication from the Chathams unique?
With nearly 10% of New Zealand’s endangered species found here, no piece of New Zealand holds higher conservation value than the Chatham Islands. Eradication could protect more endangered species than anywhere else.
The islands are 800km away from the mainland, making them defendable. The geography of the islands also means segments could be defended and easily accessed by people carrying out pest control work.
One of the most challenging predators – mustelids – aren’t present in the Chathams. Pitt Island is also free of possums and rats.
Eradication projects on inhabited islands can often be more complex as they need to consider practical and social aspects of the locals’ lives on the island. Our islands have the benefit of a community who are already involved and invested in restoration work.
Other eradication projects
We’re not starting from scratch as we plan predator eradication. There are several examples of successful eradications from Aotearoa and around the world that are informing our approach. We're also drawing on best practice approaches set out by the Pacific Invasives Initative.
You can watch a talk by eradication expert Stephen Horn online: Island eradication: lessons learnt and effort required.
Aotearoa eradication projects
Motutapu island Image: Waatea News
Ahuahu Great Mercury Island had been predator free since 2016. This island of 1872 hectares has a small population on a working farm. They focused on eradicating rats and feral cats. This was a good example of a public/private partnership working well to successfully eradicate target predators.
Antipodes-Moutere Mahue is another success story, this time on a 2000-hectare uninhabited island. Their target species was mice. The project was partially funded by a crowd-funding campaign called ‘Million Dollar Mouse’. The remote location made logistics challenging, but the island has been predator free since 2018.
Other stories highlight the ongoing challenges of eradication. Rangiototo and Motutapu islands were declared predator free in 2011. Since then, they’ve had challenges with incursions, including from a stoat in 2020 and 2021.
International eradication projects
South Georgia Island Image: Oliver Prince/South Georgia Heritage Trust
Several international eradication projects have helped protect and restore incredible natural treasures.
South Georgia Island in the Atlantic Ocean was declared predator free in 2018. At the time this was the largest rodent eradication in the world, removing rats and mice from 375,000 hectares.
A little closer to home was Lord Howe Island in Australia. With a population of 350 people and a landscape of 1,455 hectares, this project to eradicate rats and mice had several complexities. It took 17 years for them to achieve predator free status, which they did in 2019. However, they have faced rat incursions since then, demonstrating the ongoing importance of biosecurity after an eradication.
South Africa’s Marion Island was declared free of feral cats in 1992, and a plan to eradicate mice is currently underway. This uninhabited island of 29,000 hectares is home to 29 species of seabirds and a number of marine mammals.