Waiheke Island is rich in birdlife, and islanders want to keep it that way, by removing predators which disrupt the natural ecosystem and threaten the survival of several species.
When you join us for a guided walk on Waiheke, we’ll explain some of the projects that are part of Te Korowai o Waiheke, an island-wide project that aims to make Waiheke the first urban predator-free island in the world. It’s one of the ambitious large landscape predator control and eradication projects around New Zealand that won funding from Predator Free NZ 2050.
And along the walking trails you’ll see evidence of this work in the form of stoat traps and bait stations, which are managed by local volunteers and you’ll hear from us how we aim to achieve predator-free status and restore the island to its former glory.
The combined effects of introduced predators has resulted in the extinction of 52% of North Island and 47% of South Island birds. And the decline continues at an alarming rate. We can’t reverse extinction, but we can halt the decline of those that remain.
– Te Korowai o Waiheke
An estimated 68,000 native birds are killed in New Zealand by introduced predators every night. The main predators are possums, stoats and rats.
Waiheke is lucky, as possums apparently never made it to the island.
Stoats and rats are a big problem though, and there are currently about 900 rat bait stations around the islands. Local groups look after specific areas. One such group is Friends of Hekerua, which I founded a few years ago. Our volunteers now manage 25 rat bait stations and five stoat traps.
To make Waikehe predator-free, we needed to coordinate our efforts to eliminate stoats and rats, and that’s why Te Korowai o Waiheke was established. The trust receives funding from Auckland Council, Predator-Free 2050 and Foundation North.
The range of a male stoat can be up to 130 hectares (Waiheke Island is 9200 hectares). The damage done to native birds from even one stoat is large, given they need to eat a quarter of their body weight every 24 hours. Stoats have been seen in all areas of the island.
In January 2020, 1700 stoat traps will be placed in a grid across the island. We expect it will take about two years to eradicate stoats on Waiheke, followed by another two years of monitoring before the island can be declared stoat-free.
A project this ambitious will take some time. The more visible signs of success will be seeing taonga species such as kākāriki (parakeet), korimako (bellbird), tīeke (saddleback), toutouwai (robin), weta and geckos dispersing, and recovering their place throughout the island.
– Te Korowai o Waiheke
As for the rats, local volunteers currently target rats in a coordinated effort four times a year – all on the same weekend across the island. We put tracking cards in tracking tunnels first overnight to monitor our current rat population and then we remove those and put out bait for three weeks, after which we remove any remaining bait to reduce environmental load. The reason for doing it quarterly is that rats can become bait-shy.
In late 2020 a rat eradication pilot will be conducted to determine the social and operational methodology required to conduct an island wide rat eradication programme.
Read more about Walking By Nature’s commitment to the environment.
Top photo: Bellbird (Korimako). Sid Mosdell on Flickr