Tawaki breeding success close to zero
Beech mast leads to stoats leads to breeding failure …. in the third year of the Trust’s monitoring of potential predators and predation of Fiordland crested penguins, stoats at Jackson Head have proved to be a significant threat, taking virtually all eggs or chicks during the 2016 breeding season.
The 2015 season was also a disaster as adults had to forage a long way from home, often returning with too little, too late, and chicks were starving. That was presumed to be due to El Niño conditions.
In May last year, DOC confirmed a beech mast with massive seed production particularly in parts of southern South Island. It appears that has led to the expected explosion in first the rat population, followed by stoats, and the stoats have spread out from beech forests in South Westland seeking other sources of food – sadly penguin eggs and chicks in this instance.
Dr Thomas Mattern, who has been studying the foraging behaviour of tawaki during the chick rearing stage (see The Tawaki Project story below), reported that of around 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.