New Zealand Journal of Ecology (2018) 42(2): 125- 136

Assessing the population trend and threats to New Zealand’s Fiordland crested penguin using counting and demographic modelling approaches

Research Article
Helen Otley 1*
Hannah Edmonds 2
Jo Hiscock 3
Glen Newton 4
Jane Tansell 5
Paul van Klink 6
Rebecca Wilson 7,8
Ian Westbrooke 9
  1. Department of Conservation, Private Bag 701, Hokitika 7842, New Zealand
  2. Department of Conservation, PO Box 29, Te Anau 9640, New Zealand
  3. Department of Conservation, PO Box 743, Invercargill 9840, New Zealand
  4. Department of Conservation, PO Box 370, Greymouth 7840, New Zealand
  5. Southern Contractors, 330 Sinclair Rd, Te Anau 9679, New Zealand
  6. 179B Stone St, Wanaka 9305, New Zealand
  7. Department of Conservation, Haast
  8. Present address: WWF-New Zealand, PO Box 6237, Wellington 6141, New Zealand
  9. Department of Conservation, Private Bag 4715, Christchurch Mail Centre, Christchurch 8140, New Zealand
*  Corresponding author

The Fiordland crested penguin Eudyptes pachyrhynchus is one of the least studied crested penguin species, with indications the species has a declining population, which would be in line with the historic and contemporary trends for most crested penguins. To determine the current population trend of the Fiordland crested penguin, a number of monitoring programmes using both abundance counts and demographic modelling approaches were carried out between 1990 and 2010 in the northern half of the speciesí range. A 2.6% ± 0.8% annual decline rate of active nests was detected at 14 monitoring plots, and the number of nests along two coastlines declined annually by 1.2% and 2.6%. Population matrix models using site-specific demographic rates for the species at two South Westland sites indicated contrasting population trends, with one site increasing by 1.6% annually and a second site decreasing at 0.3% annually. Due to concerns about the reproductive parameters used in the model, the trajectory indicated by the nest-chick data was deemed more robust and should be used to inform management. Six potential threats to Fiordland crested penguin were reviewed against the detected population trend and specifically adult survival, but it was determined that there is insufficient understanding about the species, particularly its foraging ecology and effects of fishing and terrestrial predation, to confidently identify the key threats. Therefore, the recommended management action is to address these knowledge gaps.