Yellow-eyed penguins are slowly vanishing from Stewart Island and researchers are determined to find out why.
Workers on a five-year monitoring programme have so far found starving and diseased birds and a diminishing number of nests.
Sandy King of the Yellow-eyed Penguin Trust has spent 10 days isolated on the northern shores of Stewart Island.
"I like penguins, and I've always had an interest in them," she says.
Yellow-eyeds are one of the world's rarest penguins and it is Knight's job to monitor their decline on New Zealand's third largest island.
She says in searching for their nests, she looks for a sign of where they enter the bush.
In the early 1990s it was thought there were about 600 pairs of yellow-eyed penguins on or about Stewart Island, but in the year 2000 the trust carried out a survey, and found only 200 pairs of birds. The reason for their decline remains a mystery.
With no sign of predation, wild cats have been ruled out, so the search for nests continues. The programme is into its fourth season, with disappointing results.
"We started off with 27 nests in the area that we were monitoring in 2003 the first year of this study. And it looks like this year so far we'll have 19. The number's dropped every year," says Knight.
She sends chick carcasses for autopsy - their deaths are down to two causes.
"It's a question of, are they starving because they're ill, or are they ill because they're starving."
The race is on to find which it is, before it's too late.
