Stoat loose on pest-free Motukorea-Browns Island still free after two months

Stoats can be devastating for native species.
Stoats can be devastating for native species. Photo credit: File.

Sarah Robson for RNZ

A wily stoat on the loose on one of Auckland's pest-free islands has managed to evade capture for more than two months.

The stoat was first detected on Motukorea/Browns Island by a conservation dog in mid-March, just before the COVID-19 lockdown. Teams also spotted footprints in the sand, found stoat poo and discovered where the stoat had been hiding its kills.

Since then, dozens of traps and cameras have been set up, but the stoat has proved elusive.

Human visitors get to the island by boat, yacht or kayak - and because it's so close to the mainland, it's a popular spot for daytrippers.

Auckland Council park ranger Miranda Bennett did not think the wily stoat hitched a ride to the island with one of them, however.

"We're pretty sure it swam here, it's unlikely to have transported on a boat because they're quite shy of people," she said.

"They are good swimmers, we know that. It's only just under 1.5 kilometres from Musick Point, so it's probably come from somewhere Howick sort of way."

Bennett said the stoat has been dining out on rock pigeons, with the island's high cliffs not proving much of a deterrent for the hungry mustelid.

"They're just the ultimate predator, nothing really stops them," Bennett said.


With so many native birds on the island, including New Zealand dotterels and the critically endangered shore plover, Bennett said it was important they caught the stoat before it changes its tastes.

Traps have been set all over the island. As well as bait, there's an ink pad in each trap to pick up any footprints from whatever has been inside.

"So far our stoat hasn't left us any footprints, but they're very clever. We do know from research that they will reach across an ink pad and grab the bait and manage to get out without leaving a footprint so our one so far has been sneaky, which is really frustrating," Bennett said.

They've been experimenting with different types of bait that might be more to the stoat's tastes - rabbit, whole egg mayonnaise, dead weasels.

"We're trying to think like a stoat really, what might intrigue it and make it want to go inside one of these tunnels or one of our traps. We gave chicken sausages a go, but that went off pretty quick, so that wasn't quite so good," Bennett said.

The cameras trained on the nine traps had not spotted anything either, but they did pick up something else - people who should not have been there.

"Some of the people appeared to be going for a walk, probably going up to the summit for the views, other people seemed to be here for a picnic, a few wines on the beach in the evening. Someone was here at 1am, we're not quite sure what they were doing on the island."

Conservation dogs have also been called in to help with the search - Lois Clayton and 12-year-old border terrier cross Gecko scoured the 60-hectare island for any sign of the stoat.

"She's a sniffer dog so her job is to find any scent of the animal, whether it be where the animal's walked, where it's had a pee or a poo, where it's had a kill, or where it's hunkered down in a burrow or tree," Clayton said.

Gecko's highly trained nose did pick up a scent during her hours of searching, but it appeared the Motukorea/Browns Island stoat had got away again.