Thesis: The causes and consequences of intergroup interactions in mountain gorillas
Group living animals often interact and compete with neighboring groups for access to valuable resources, such as food, mates and sleeping sites. These interactions can involve individuals directing aggressive, neutral and/or affiliative behaviours towards members of the other group, although the factors determining such outcomes have yet to be sufficiently explored. Factors influencing the escalation or the prevention of intergroup conflict have long been hypothesized, and the overall aim of my research is to better understand the social and ecological influences on the outcome of an encounter between groups of social primates. Intergroup conflict can result in participating groups acquiring dominance, losing or recruiting fertile females, obtaining access to valuable resources and potentially losing group members to fatal injuries and infanticide. Intergroup encounters can therefore affect individual fitness, and potentially within-group social relationships. Thus, the causes and consequences of intergroup encounters are extremely relevant in a growing population where social groups share their home range with multiple other groups. For this research, I have observed a wild, but fully habituated mountain gorilla population in the Volcanoes National Park, Rwanda that inhabits an area of high and increasing population density. I have supplemented my own observations with 14 years of data from a long-term database kept by the Dian Fossey Gorilla Fund’s Karisoke Research Center that include detailed reports of hundreds of intergroup interactions.
Why my research is important
Given the endangered status and charismatic nature of mountain gorillas, my work will help to raise public awareness and possibly offer a better understanding for conservation management of this species. Specifically, current conservation efforts to increase the size of this population have been very successful, and groups are therefore sharing more of their home range with others than in the past. This has led to an increase in intergroup encounters, which are often aggressive and potentially lethal for some individuals. Similarly, an increase in intergroup encounters may enhance the risk of disease transfer throughout the population, which poses a threat to successful conservation efforts. A better understanding of the factors that regulate intergroup dynamics is therefore essential. In addition, my research has the potential to provide important insights into human social evolution.