A project studying Fiordland crested penguins at Jackson Bay has been extended after almost every chick and egg in the colony was eaten by stoats.
The West Coast Penguin Trust is in its third year of monitoring the colony on Jackson Head.
Before Christmas, stoats ate almost all of the eggs and chicks.
The previous season was also a disaster as adult penguins from the colony had to forage a long way from home, often returning with too little, too late, leaving the chicks starving. That was presumed to be due to El Nino conditions.
Last May the Department of Conservation confirmed a beech forest mast with massive seed production, particularly in parts of the southern South Island.
According to the penguin trust, this appears to have led firstly to the predicted explosion in the rat population, followed by stoats, and the stoats have then spread out from beech forests seeking other food - penguin eggs and chicks.
The trust said Thomas Mattern, who has been studying the foraging behaviour of Fiordland crested penguins (tawaki) during the chick rearing stage, reported that of about 40 nests in the Jackson Head area, only five chicks were still alive in mid-November, "when the colony should have been alive with the noise of adults and chicks almost ready to fledge".
The trust's project was planned for three years, "but with this exceptional event, a fourth year is now planned, collaborating with Dr Mattern, to help better understand the situation".
"This should allow fact-based conservation management regimes to
be developed and put in place to conserve populations and/or habitats as required."
- Greymouth Star