Preliminary counts of hoiho show severe declines for nest numbers in locations in the Catlins and Bravo Islands, Rakiura. Other mainland sites have not shown the same decline.
DOC Southern South Island Operations Director Aaron Fleming says the 2018/19 breeding season was complex with two significant starvation events which have impacted this year’s breeding population.
“Last season DOC and the Yellow-eyed Penguin Trust (YEPT) undertook the most intensive management of hoiho to date, with additional rangers on the ground monitoring birds and responding to management needs.
“Despite the huge effort from rangers checking daily, and massive support from rehabilitators and veterinary services treating the underweight birds, the impact of the starvation events resulted in this low nest count.”
Yellow-eyed Penguin Trust general manager Sue Murray says additional searches will be carried out in the coming weeks in the hope of finding more nests, but it is not expected that the pattern of decline will change.
“Last season the number of Catlins hoiho observed during the moult was low. A large number of these were breeding females which have not returned to breed this year, resulting in this low count. For the hoiho conservation community, it’s devastating.”
The causes behind starvation events are complex and unable to be answered with certainty. One event that occurred in November 2018 was a major flood which resulted in large amounts of sediment being discharged from the Taieri and Clutha Rivers. Hoiho are visual hunters so murky waters make it more difficult to see prey.
Last season more than 400 hoiho across the mainland received additional care and rehabilitation at the Dunedin Wildlife Hospital, Penguin Place and Penguin Rescue.
Many factors can influence and impact hoiho populations such as human disturbance, dog attacks, fisheries interactions, predation, disease, habitat loss and warming seas.
For the 2019/20 season DOC and YEPT along with site managers have increased on the ground effort, with extra funding from Budget 2018, to ensure at risk adults and their chicks receive a high level of care.
In August, DOC, YEPT, Ngāi Tahu and Fisheries NZ released a draft strategy and action plan which went through public consultation and is currently being finalised.