Ferret kills most of colony’s shearwater chicks

A Catlins seabird colony has been dealt "a devastating blow" after a single ferret killed three-quarters of the colony’s sooty shearwater (titi) chicks recently.

Sixteen of the 21 chicks were discovered dead last week at the Long Point/Irahuka reserve complex.

Forest & Bird project manager Francesca Cunninghame said examination of trail camera footage revealed a lone ferret was the culprit, decapitating some defenceless chicks and leaving others with fatal bite wounds to the neck.

She visited the seabird colony twice last week to check on the chicks, which were due to fledge in a matter of weeks.

"It’s grim, very sad news.

"The chicks have been sitting in their burrows since they were laid as eggs way back in December. They were all in good condition, too."

Titi are classified as "At risk — declining".

The colony is located on a reserve owned by the Yellow-eyed Penguin Trust, where Forest & Bird volunteers assist with predator control.

Since 2017, volunteers have increased monitoring of the titi colony as part of Forest & Bird Dunedin branch’s Bring Back the Seabirds’ project.

"This incident is a devastating blow to the hard work of volunteers, but one they are all too familiar with."

A ferret wiped out all the chicks in another titi colony on the Otago Peninsula in 2019, she said.

The attacks highlighted both the damage that could be dealt by a single trap-shy predator and the limitations of ground-based predator control.

"Working together with field rangers from the Yellow-eyed Penguin Trust, we’re funding extra trapping with enticing ferret-attractive baits.

"We really hope we can catch the killer so some of the titi can survive to fledging."

Trail camera footage also revealed a feral cat in the seabird colony, which had since been captured.

"We recorded the cat sniffing at burrows.

"This was a worry, because the chicks are starting to emerge from their burrows and sit on the surface, making easy pickings for a cat.

"We’re relieved it's no longer a threat to the remaining chicks."