The yellow-eyed penguin is endemic to New Zealand and is one of two penguin species with the most fragile conservation status on the planet. It is a long-lived species and population viability analysis shows that even a small increase in adult mortality augments extinction probability dramatically. The yellow-eyed penguin population on the New Zealand mainland, including Stewart Island, is small (600-800 breeding pairs). Previous population strongholds such as on the Otago Peninsula are declining. Since the mainland population is genetically distinct from sub-Antarctic populations (inferred immigration rate 0.003 per generation) the current loss of yellow-eyed penguins along the Southeast coast of the New Zealand South Island and in the Foveaux Strait will not be compensated by immigration. Fisheries bycatch may be substantial, particularly in the commercial set net fisheries; however, the information currently available does not allow assessing the full extent of fisheries impact.
Here we have reviewed and collated information existing to date on yellow-eyed penguin population parameters including range and distribution, population levels and trends, adult survival, juvenile survival, age of first breeding and fecundity. Furthermore, we summarised our current understanding of yellow-eyed penguin marine ecology and foraging patterns.
Important gaps in our knowledge have been identified and we provide recommendations for future research in order to better assess the direct and indirect effects of commercial fisheries on yellow-eyed penguins.