Increasing numbers of stoats have been caught in a Wellington area ''mainland island'', including one monster stoat 45cm long.
Greater Wellington Regional Council has stepped up trapping efforts in the Wainuiomata Mainland Island, to try to combat pest problems.
What's known as a ''mast year'' has created extra food for rodents, with increased tree seeds and other food sources.
Now those increased trapping efforts have caught what the Council calls a "trophy size stoat", weighing 450g and 45cm long.
The average weight of a stoat is only 324g.
Greater Wellington Regional Council biodiversity management team leader Richard Romijn said they usually caught about 30 stoats a year.
"They travel quite long distances, so they're likely to keep re-invading the habitat from the surrounding landscape.
"This one was particularly large, definitely a big animal."
Romijn said the problem was partly one of success.
"Probably we've got animals coming into this area because it's a really good area, it's good for growing things.
"We've got old growth forest, we've got possum numbers down which leaves it a really productive environment.
"So, therefore, it's good for a range of animals, whether they be native animals or introduced animals like stoats."
Greater Wellington staff recently lodged a submission on opportunities to work more closely with the Department of Conservation (DoC), especially in areas where DoC land adjoins regional parks.
Suggested changes covered areas including biodiversity management, pest management, recreational use, and collaborative restoration projects.