The effects of human disturbance on the seabirds and seals at sub-Antarctic Marion Island

Doctoral Thesis


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University of Cape Town

Animals at Marion Island can be affected by logistic disturbance (especially helicopter noise), incidental pedestrian disturbance and research disturbance. The responses of wandering albatrosses (Diomedea exulans) and king penguins (Aptenodytes patagonicus) were investigated through standardised pedestrian approaches. Intensity of behavioural responses and levels of prolactin (females only) indicated that adult wandering albatrosses had become sensitised by high levels of chronic disturbance. Responses were greatest during the Prospecting and Early Incubation phases. Frequency of disturbance did not influence behavioural responses, but birds visited most often over three consecutive days had the lowest chick survival. Guarding king penguins were less likely to move away during disturbance than non-breeding groups. Visit duration and approach distance affected behavioural responses. There was evidence of habituation by king penguins to current levels of incidental disturbance. Grey-headed albatross (Thalassarche chrysostoma) adults and chicks showed short-term behavioural responses to research disturbance, and recovery times were variable. Level of chronic disturbance did not explain breeding success differences between colony sections. Instantaneous scans or counts of guarding and brooding gentoo penguins (Pygoscelis papua), incubating Crozet shags (Phalacrocoraxmelanogenis), pre-fledging grey-headed albatross chicks and non-breeding king penguins were made before and during helicopter operations.

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