1. Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
2. Kalahari Meerkat Project, Kuruman River Reserve, Northern Cape, South Africa
3. School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, UK
4. Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
5. Animal Behaviour, Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstr. 190, Zurich 8057, Switzerland