1. Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, CA 95616, U.S.A.
2. Department of Biological and Molecular Sciences, University of Stirling, Stirling, U.K.
3. Large Animal Research Group, Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, U.K.
4. P.O. Box 185, Kigoma, Tanzania
5. The Zoological Society of London, Institute of Zoology, Regent's Park, London, NW1 4RY, U.K.
6. Serengeti Wildlife Research Institute, P.O. Box 661, Arusha, Tanzania
7. P.O. Box 822, Cape May Courthouse, NJ 08210, U.S.A.
8. Fieldhead, Amberley, Stroud, GL5 5AG, U.K.