1. Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
2. Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
3. Department for the Ecology of Animal Societies, Max Planck Institute for Animal Behavior, Bücklestraße 5a, 78467 Konstanz, Germany
4. Center for the Advanced Study of Collective Behavior, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
5. Human Biology Program, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
6. Rocky Mountain Research Station, Colorado State University, 240 W Prospect St, Fort Collins, CO 80525, USA
7. Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA
8. Department of Anthropology, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109, USA