1. Department of Biological Sciences, University of Cape Town, Private Bag X1, Rondebosch, 7701, South Africa.
2. School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Wits, 2050, South Africa.
3. South African Environmental Observation Network, care of the Department of Biological Sciences, University of Cape Town, Private Bag X1, Rondebosch, 7701, South Africa.