1. Research Fellow, Department of Environmental Sciences, UNISA, P.O. Box 392, UNISA, 0003 South Africa
2. Emeritus Professor Wildlife Management, University of Pretoria, Private Bag X20, Hatfield, 0028 South Africa
3. Emeritus Professor of Soil Science, University of Pretoria, Private Bag X20, Hatfield, 0028 South Africa
4. Research Consultant, Department of Statistics, University of Pretoria, Private Bag X20, Hatfield, 0028 South Africa
5. Research Assistant, Centre for Wildlife Management, University of Pretoria, Private Bag X20, Hatfield, 0028 South Africa