Yellow-eyed penguin numbers along the Otago and Southland coastlines have remained low for another breeding season.
The Yellow-eyed Penguin Trust estimates there are 250 breeding pairs on mainland New Zealand as their annual breeding season comes to an end.
In total there are believed to be around 1700 breeding pairs of yellow-eyed penguins, with most living on the subantarctic islands.
The Department of Conservation said the estimate for pairs on the mainland this year was similar to the past two seasons, but those numbers were considerably lower than previous years, where there were between 400 to 600 breeding pairs.
Like previous years, there had been some unexplained adult deaths, DOC said.
This year there have been six unexplained deaths, with two adult birds found dead on Otago beaches in the last week.
In 2013, 67 penguins were found dead.
Coastal Otago operations manager Annie Wallace said despite much research into the reasons for these deaths and ruling out many possibilities, the exact cause had not yet been identified.