1. African Amphibian Conservation Research Group, Unit for Environmental Sciences and Management, North-West University, South Africa
2. Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Diepenbeek, Belgium
3. South African Institute for Aquatic Biodiversity, Makhanda, South Africa
4. Department of Environmental Sciences, Faculty of Science, Open University of the Netherlands, Heerlen, the Netherlands
5. Biology Department, Vrije Universiteit Brussel, Brussels, Belgium