Long-term individual-based studies can be central to collecting data on aspects of individual and population biology and ecology. Photo-identification often underpins longterm individual based studies, particularly for cetaceans. Bottlenose dolphins (Tursiops truncatus) are long-lived with low reproductive rates and complex social structures, while showing plasticity in their behaviour, biology and ecology. As such long-term individual based studies are key to investigating the complexities of their population dynamics. My aim for this thesis was to synthesise over two decades of photo-identification data with the intention of exploring the value and contribution of a long-term individual based photo-identification study and answer key questions about the ecology and biology of bottlenose dolphins in Scottish waters. This thesis provides the first data on distribution and status of bottlenose dolphins around Scotland. Results highlighted the smaller population on the west coast split into two discrete communities with different ranging patterns and provided the first evidence that the highly mobile east coast population may be increasing. For the east coast of Scotland bottlenose dolphin population, laser photogrammetry identified morphological differences (larger size, no sexual dimorphism, no sex differences in growth) and highlighted fitness consequences to variation in early calf growth (calves that died over their first winter were significantly shorter). This thesis also identified differences in social structure over two decades at the two extremes of the population's range, potentially caused by or a consequence of, range expansion. Finally, this study provided empirical evidence of increasing trends in population abundance, reproductive rate and calf survival. This is a rare example of empirical evidence of a positive trend in demographic parameters of a cetacean population using a marine protected area. This work highlights the need for long-term individual based data to detect biologically meaningful change and suggests this small bottlenose dolphin population is a conservation success story.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:737950 |
| Date | January 2017 |
| Creators | Cheney, Barbara Jean |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=236113 |
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