1. Department of Conservation Ecology & Entomology, Stellenbosch University, Matieland, South Africa
2. Natural Resources and the Environment, Council for Scientific and Industrial Research, Stellenbosch, South Africa
3. Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa
4. Natural Resources and the Environment, Council for Scientific and Industrial Research, Pretoria, South Africa
5. Centre for Invasion Biology, Stellenbosch University, Matieland, South Africa