1. Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
2. Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya
3. Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
4. Duke Population Research Institute, Duke University, Durham, NC, USA
5. Department of Biology, Duke University, Durham, NC, USA
6. Center for Social Research, University of Notre Dame, Notre Dame, IN, USA
7. Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
8. Department of Veterinary Anatomy and Physiology, University of Nairobi, Nairobi, Kenya