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Ecological consequences and social drivers of human-wildlife interactions: The case of food-provisioning of bottlenose dolphins in Bunbury, Western Australia

Senigaglia, Valerie (2020) Ecological consequences and social drivers of human-wildlife interactions: The case of food-provisioning of bottlenose dolphins in Bunbury, Western Australia. PhD thesis, Murdoch University.

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Abstract

Food-provisioning of free-ranging animals can result in significant impacts on individual behaviour, vital rates and population demographic processes. In Bunbury, Western Australia, a limited number of free-ranging Indo-Pacific bottlenose dolphins (Tursiops aduncus) are routinely provisioned through a state-licensed tourism program. In this thesis, I used dolphin demographic data spanning ten-years supplemented by long-term historical- (>25 years) and focal follow data, to investigate the fitness consequences and proximal effects of food-provisioning on the Bunbury dolphin population. I also explored the support and perceived importance of dolphin food-provisioning from the public. Demographic analyses indicated provisioned females had significantly lower reproductive success than non-provisioned females with only 38% of their calves surviving to weaning age (in contrast 77% survival rate of calves from non-provisioned mothers). Markov Chain and social network analyses revealed that provisioned dolphins socialize significantly less and have numerous but loose associations in comparison to their non-provisioned counterparts. I hypothesize that food-provisioning promotes an impoverished social environment which, in turn, can decrease opportunities for calves of provisioned females to develop strong social bonds with conspecifics. Population Viability Analyses forecasted an 85% decline in population size over the next five decades with food-provisioning significantly contributing to this decline. Simulations to explore the possible effects of different stressors (environmental and human-caused) indicated that the dolphin population is slightly susceptible to unusual mortality events and additional human disturbance, however their effects was relatively small compared to the effect of food-provisioning. Finally, through self-respondent questionnaires, I identified a gap between tourists’ desires for close-up encounters, their concern for dolphin welfare and the documented negative impacts of provisioning. Considering the multiple stressors affecting this dolphin population, I recommend that wildlife agencies eliminate food-provisioning and develop public education programs to prevent illegal feeding of wild dolphins.

Item Type: Thesis (PhD)
Murdoch Affiliation: Environmental and Conservation Sciences
United Nations SDGs: Goal 14: Life Below Water
Supervisor(s): Bejder, Lars, Christiansen, Fredrik, Hughes, Michael and New, L.
URI: http://researchrepository.murdoch.edu.au/id/eprint/57301
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