Our project centres on the eradication of predators from Rakiura – not the control of predator numbers. Even though both sometimes use the same tools, eradication permanently removes all identified pest species with ongoing surveillance and management of reinvasion risks.
A predator removal project of this complexity, on an island of this scale, has never been attempted before. This means we will learn new techniques and innovations that could be applied not only in Aotearoa towards a predator free New Zealand but also for restoration projects around the world.
Islands make up just 5.3% of Earth’s land area, and since AD1500, they have lost 75% of all known bird, mammal, amphibian, and reptile species due to extinction. Right now, they are home to 36% of our most critically endangered species.
(Source: Holmes et al., 2019.)
Eradication projects are highly complex, and many have long periods of control work before fully committing to a focused intensive eradication effort. The eradication process typically involves five stages: Feasibility, Knock-down, Mop-up, Verify, Biosecurity.
Re-invasion risk and post-project biosecurity are key considerations for the feasibility of every eradication project. A strong biosecurity programme, which has been tailored to the specific needs of the individual island, is essential to preventing re-invasion – and avoiding another costly eradication operation in the future.
Aotearoa New Zealand has worked on some amazing eradication projects, and is constantly building knowledge and capability for taking on these large projects.
The learnings from these projects are hugely important for us here at Predator Free Rakiura. Rakiura/Stewart Island is inhabited, and 160,000 hectares. It will be New Zealand's largest island eradication project if successful. We are getting ready to move into the feasibility stage where trials will be used to come up with an innovative planned approach to predator eradication.
Read on to find out about:
Rangitoto-Motutapu Islands - 3,881 hectares combined, uninhabited. Predator free since 2011.
Ahuahu-Great Mercury Island - 1872 hectares, inhabited by a small population on a working farm. Predator free since 2016.
Antipodes-Moutere Mahue Island - Uninhabited, 2,012 hectares. Completed.
New Zealand's capability building for rodent removal. Image source: Veronika Frank, New Zealand Department of Conservation.
Predators: 3 species of rats, stoats, mice, feral cats, hedgehogs, rabbits
Methods used:
What did they learn?
Predators: rats & feral cats
Methods used:
What did they learn?
Predators: mice
Methods:
What did they learn?
There are many things we can learn from island eradication projects around the globe. Check out some of the key learnings from the global projects below:
As well as learnings from eradication projects there are lots of lessons we can gain from scientific innovations in current predator control. Find out more about some of the latest trials and scientific innovations here.
At the time, this was the largest rodent eradication in the world.
Predators: rats and mice.
Methods used:
What did they learn?
At the time, this was the largest rodent eradication on a permanently inhabited island.
Predators: rats and mice.
Methods used:
What did they learn?
Declared free of feral cats in 1992.
Predators: Feral cats (note: operational planning for a project to eradicate mice is currently underway).
Methods used:
What did they learn?