**Acknowledgements**

This work was funded by a Canadian Natural Sciences and Engineering Research Council grant to A.R.E. Sinclair. We thank the Serengeti Wildlife Research Centre, Serengeti National Park, University of Dar es Salaam, Tanzania Wildlife Research Institute, Tanzania National Parks, and Tanzania Commission for Science and Technology for their help and permission to conduct this research. We are grateful to Stephen Makacha, John Mchetto, Joseph Masoy, and Dr. Bukombe John for their assistance with fieldwork.
