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Subject: search.filters.subject.Enderby Island

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    Impacts of human disturbance stimuli on the behaviour and breeding biology of Subantarctic Yellow-eyed Penguins (Megadyptes antipodes) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Palmerston North, New Zealand
    (Massey University, 2018) French, Rebecca Kay
    Eco-tourism is increasing in popularity worldwide, particularly in previously isolated areas such as Antarctica and the subantarctic. This may be increasing the levels of human disturbance stimuli (human-related presence, objects or sounds), which can have impacts on wildlife at an individual level (behaviourally and physiologically) and at a population level. Human disturbance (the response of an animal to a disturbance stimulus) has been studied in most penguin species, showing both inter- and intra-specific differences in responses to disturbance stimuli at similar distances. The Yellow-eyed Penguin (Megadyptes antipodes) is negatively impacted by human disturbance stimuli, but very little research of any kind has been conducted on the subantarctic population. This is despite some areas within the subantarctic being regularly exposed to tourism, and the subantarctic population making up an estimated 60% of the entire species. I used an experimental approach to investigate the behavioural impacts of human disturbance stimuli on subantarctic Yellow-eyed Penguins, on Enderby Island. Human presence significantly changed their behaviour, resulting in an increased time spent vigilant and a decrease in the frequency of maintenance behaviours. By modelling the probability of disturbance at varying distances from the penguin to the human, I showed the current minimum approach distance of 5 m (with a 99% chance of disturbance) was not effective. I also quantified the breeding biology of subantarctic Yellow-eyed Penguins, and investigated the impact of human disturbance stimuli on their breeding success. There was no difference in nesting success (expressed as number of eggs, chicks and fledglings surviving per pair) between the disturbed and undisturbed site and no significant difference in the average weight and body size of fledglings at the disturbed site compared to fledglings at the undisturbed site. My results indicate that at current levels human disturbance stimuli has a behavioural impact on subantarctic Yellow-eyed Penguins, but a population-level impact was not detectable. This may be due to the low level of tourism and high degree of tourism management in the New Zealand subantarctic, and the resulting low number of interactions between penguins and humans. Enderby Island tourism may therefore be an example of sustainable eco-tourism and successful management, although more research including multi-year studies would be needed to confirm this.
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    Causes of mortality and characterisation of Mycobacteriosis in adult New Zealand sea lions (Phocarctos Hookeri) at Enderby Island : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science in Wildlife Health at Massey University, Manawatū, Palmerston North, New Zealand
    (Massey University, 2017) Lenting, Baukje Mirjam
    The New Zealand sea lion (Phocarctos hookeri) is classified as endangered and “Nationally Critical” due to a declining population and restricted population range. There have been recent bacterial epizootic events at the breeding colonies of this species, however the role of disease in the population decline is not known. As part of the investigation into the population decline, the species management plan recommends investigation of disease agents affecting this species, their epidemiology and their long-term effects on population dynamics. Since the 1998/1999 breeding season, post mortem examinations have been performed on deceased New Zealand sea lions at the Enderby Island breeding colonies during each breeding season, including the collection of samples for histology and bacteriology. This study describes the causes of mortality in New Zealand sea lions one year of age and older at Enderby Island between the 1998/99 to 2010/11 breeding seasons inclusive, using the archived post mortem reports, histology samples and bacteriology samples. Conspecific trauma was found to be a significant cause of mortality (34.3%), as were various infectious causes (35.7%). The organism Klebsiella pneumoniae was isolated from non-pup New Zealand sea lions both from individuals that died from other causes and individuals that showed apparent morbidity as a result of this bacteria. These findings suggest that older animals may be reservoirs of infection for K. pneumoniae, which causes significant mortality in neonatal New Zealand sea lions. Another important infectious agent that was described in non-pup New Zealand sea lions was Mycobacterium pinnipedii, which caused both subclinical and clinical disease. Mycobacteriosis of the lymph nodes, lungs, pleura, liver, peritoneum and reproductive tract was described in this study. Strain determination of the M. pinnipedii isolates grown show only minor strain variation among isolates, which may reflect the isolated geographic distribution of these animals. There was no apparent association between the individual strains of M. pinnipedii and their pathogenicity as indicated by the pathology present in infected animals.