An investigation of the causes of mortality in yellow-eyed penguins (Megadyptes antipodes) across their range with specific emphasis on the role played by Leucocytozoon : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science in Wildlife Health at Massey University, Palmerston North, New Zealand

• Main Author: Argilla, Lisa Shelley
• Format: Thesis
• Language: English
• Published: Massey University 2015
• Subjects: Yellow-eyed penguin; Megadyptes antipodes; Leucocytozoon; Austral; New Zealand; Campbell Island; Enderby Island
• Online Access: http://hdl.handle.net/10179/8301

Over the past 40 years, there have been frequent mass mortality events documented in yellow-eyed penguins (Megadyptes antipodes). In most cases, these mortality events have resulted in significant adult or chick mortality resulting in a population decline. Previous studies in yellow-eyed penguin mortality have been attributed to events such as unidentified phytotoxins, starvation, poor nutrition, climatic events and infectious causes. However, the full impact of these factors on yellow-eyed penguin population decline and mortality events is not well understood. During the Austral summer of 2008/09, there were mortality events documented in both the subantarctic and mainland yellow-eyed penguin populations with different patterns of mortality and different factors associated with the mortality between both locations. A high overall prevalence of Leucocytozoon spp. in association with a high incidence of chick mortality was observed during this period on Enderby Island. Despite its endemic nature in this population, statistical analysis demonstrated that infection with Leucocytozoon did not play a significant role in mass mortality of Enderby Island chicks, other than as a cause of sporadic individual mortality. The Leucocytozoon spp. sequences detected lead to the conclusion that the Leucocytozoon parasite is endemic in yellow-eyed penguins and has a higher prevalence in penguins from Enderby Island than those from Campbell Island and the mainland of New Zealand. The Enderby Island yellow-eyed penguins are infected with a Leucocytozoon spp. that is genetically distinct from that found in other yellow-eyed penguin populations. The role of Leucocytozoon in the high levels of chick mortality in the yellow-eyed penguins remains unclear. A very low mortality was observed in the Catlins population despite there being a high level of human impact at some nest regions within this location. A high level of mortality was described in the Otago Peninsula population with this population affected by high human disturbance ...