After two difficult breeding seasons due to a mystery illness and starvation, the discovery of the 25-year-old bird at Tavora Reserve, near Palmerston, is a good news story, Yellow-eyed Penguin Trust general manager Sue Murray says.
The bird is believed to be one of only three banded yellow-eyed penguins known to reach that age and the only one still alive.
''It's impressive. Very unusual,'' Mrs Murray said.
''Band number was J10001. Don't you love it?''
The bird was banded as a chick at Tavora in 1989 by the Department of Conservation.
Doc conservation services manager coastal Otago Dave Agnew said J10001 was at the older end of the age spectrum for the penguins.
J10001's first recorded breeding was in 1995 and it last bred in 2011, helping produce two chicks.
When it was seen late last month at Tavora, it was finishing its moult and it was thought it would go straight back out to sea.
