1. Dept of Zoology and Entomology; Mammal Research Inst., Univ. of Pretoria; Private Bag X20 Hatfield, Pretoria 0028 South Africa
2. Centre for Statistics in Ecology, Environment and Conservation, Dept of Statistical Sciences; Univ. of Cape Town; Rondebosch South Africa
3. African Climate and Development Initiative; Univ. of Cape Town; Rondebosch South Africa
4. INRA; UMR 0985 Ecology and Health of Ecosystems; Rennes France