Eradication kills islands’ mice threat

A remote and windswept biodiversity hot-spot in New Zealand’s subantarctic islands has been formally declared mouse-free, following one of the most sophisticated pest eradication projects undertaken anywhere in the world.

The Antipodes Islands, about 760km southeast of Bluff, were once home to about 200,000 mice that preyed on bird chicks and eggs, invertebrates, and plants.

The impact was enough to alter the biodiversity of the 2100ha island group, recognised as a World Heritage site for its outstanding natural values.

Fears had grown after mice were seen eating alive large seabird chicks in nests on two south Atlantic islands.

It wasn’t known whether that was happening on the Antipodes, but this behavioural shift was seen as a risk for all 25 bird species breeding there. That threat no longer exists. The islands have been formally declared rid of the scourge by the Department of Conservation’s Island Eradication Advisory Group.

It was largely thanks to the fundraising “Million Dollar Mouse” project.

The five-year project involved preparations and hut repairs, a baitdrop in June 2016, and monitoring by teams that searched the island for a month and found no sign of mice.

“The success of this project was built on the lessons and experience from many other island eradications in New Zealand and abroad,” DoC project manager Stephen Horn said. “The subantarctic islands are remote, but the role they play in global conservation as the home for so many unique species can’t be overstated.”