21 May 2024

No evidence of mice on Rakiura in trapping project

11:13 am on 21 May 2024
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Environment Southland contractors set up bait traps, and cameras at eight sites on Stewart Island. Photo: RNZ / Nate McKinnon

No mice were detected in the latest rodent hunt on Rakiura despite earlier concerns they may be on the island.

A 2023 camera survey by Predator Free Rakiura showed images of small rodents which could be mice on Stewart Island.

Environment Southland contractors set up bait traps, and cameras at eight sites to find out whether there was an established population of mice on the island.

They were monitored for two weeks before being removed.

The regional council's biosecurity and biodiversity operations manager Ali Meade said 26 rats were trapped during the project which began earlier this month.

"Most of the rats captured were kiore (Pacific rat). Some of them are very small, and one was caught in a mouse trap. The images captured by Predator Free Rakiura in 2023 are likely to have been of a small kiore, not of a mouse," Meade said.

The results didn't prove that mice weren't present, but were encouraging as an established population of mice could have a devastating impact on the conservation efforts on the island, she said.

Mice can form huge populations quickly, compete with native birds for food, and have been known to eat chicks, especially those in ground nests.

Environment Southland reminded people travelling to Stewart Island to remain vigilant and thoroughly check their gear for any stowaways.