He suspected it was an adult male looking for a mate and being unable to find one, had gone back out to sea to look elsewhere.
Stoats were good swimmers so were more easily able to get to the island than some other pests, Morgan said. They were spotted on the island about once a year.
Earlier notable incursions on the island included a dog illegally walked on the land by some unidentified boaties and a ferret that tragically ate legendary breeding kiwi Sir Edmund Hillary.
Morgan said it was still unknown how the ferret made it to the island. Ferrets can swim but not as well as stoats.
The island is covered by a network of traps and monitored to catch various predators.
Sarah Curtis is a news reporter for the Northern Advocate, focusing on a wide range of issues. She has nearly 20 years’ experience in journalism, much of which she spent court reporting. She is passionate about covering stories that make a difference