Ben Buckley, PhD Candidate
University of Cambridge
Co-Investigator: Michael Krutzen
Co-Investigator: Helen Morrogh-Bernard
Approved: April 2011
Construction of models for the social and mating systems of extinct hominoids is contingent upon data from their extant relatives. In order to be inclusive, these models must incorporate the full range of social and mating systems seen in extant apes, and particularly their extremes. Being largely solitary, and expressing delayed male bimaturism and female philopatry, orangutans appear to represent such an extreme. Ranging and dispersal are integral to a species' social and mating systems, and their study is important for understanding the costs, benefits and evolution of these systems. The ranging and dispersal of the African apes and of female orangutans is now reasonably well known, but our knowledge of these behaviours in male orangutans is poor, owing to their very large home ranges. I will collect data on ranging and dispersal of male orangutans in a large, unfragmented habitat. Working from seven different sub-sites, I will search for and follow orangutans, and collect DNA samples throughout a 10,000 ha area of unbroken forest, which is about five times larger than in any previous orangutan study. I will map individual ranging data using GIS and collect genetic samples to assess relatedness between males and females throughout the area, therefore enabling assessment of male dispersal from natal ranges. The huge size of this study area, plus the incorporation of genotyping technology, will enable me to address a number of questions relating to male dispersal and ranging (over short, medium and long distances), crucial for understanding the mechanics of the orangutan mating system. This, in turn, is important for understanding the range of social and mating systems in extant apes and, by inference, our extinct ancestors.