Image: Crystal Brindle | DOC

Introduction

Kiwi populations around the country are declining at an average of 2% a year – a serious situation. It’s mostly due to predation upon kiwi chicks by stoats, cats, dogs and ferrets. The goal for Save Our Iconic Kiwi is to turn this decline around, so that every type of kiwi is increasing in number.

Kiwis for kiwi and DOC received significant government funding in 2015 to Save Our Iconic Kiwi.

DOC’s focus is on those kiwi species suffering the greatest rate of decline in the remote backcountry of the South Island: Fiordland tokoeka, Rakiura (Stewart Island) tokoeka and great spotted kiwi/roroa.

Success will come from gathering a better understanding how to effectively manage kiwi and working in collaboration with others.

Fiordland tokoeka

In 2017, we started monitoring southern Fiordland tokoeka (kiwi) at Shy Lake, between Wet Jacket Arm and Breaksea Sound. The goal is to gather data before and after an aerial 1080 operation to ensure that we are controlling pests in large, remote areas of Fiordland in the most effective and efficient way to save the most kiwi.

In the absence of pest control, every chick we monitored was killed by a stoat.

The Fiordland Kiwi Diaries

Read about the work the Save Our Iconic Kiwi team have done in our blog series, the Fiordland Kiwi Diaries. The posts are written by DOC Fiordland kiwi ranger Tim and they follow his journey, along with a handful of other dedicated DOC rangers, tracking down kiwi nests and monitoring chicks.

The research behind Save Our Iconic Kiwi

We already know that intensive trapping programmes in the South Island increase kiwi populations by about 1.2%, but our goal is a 2% increase. Previous research has shown that aerial 1080 operations increase North Island brown kiwi populations. We need to find out if aerial 1080 is a successful management tool for great spotted kiwi and Fiordland tokoeka (as they differ in productivity and behaviour to North Island brown kiwi and live in predominantly mast-driven ecosystems).

The Shy Lake project, which Tim blogs about, is a way to gather this information, and there’s also a great spotted kiwi chick recruitment study in Kahurangi National Park.

We can confidently conclude that stoats are the main threat to South Island kiwi at these sites.

From the information we now have, we know we need to manage larger areas of habitat to ensure we protect more South Island kiwi.

What we’re doing now

Monitoring results have shown a need for action. 1080 is proven to work safely, effectively and efficiently in reducing predators, and we need to use it to save our native wildlife and forests.

To protect southern Fiordland tokoeka, we’re planning to treat habitat around Shy Lake and measure chick survival after the operation. This will confirm if aerial 1080 is as effective at protecting Fiordland tokoeka as we know it is for North Island brown kiwi.

While it’s hard to watch the chicks suffer predation at the Shy Lake study site, our highest chance of success is to wait until there are enough rodents in the area that will act as vectors of the toxin to stoats. If we act too early, we’re unlikely to be successful in reducing stoat numbers and chicks are unlikely to survive.

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