1. College of Natural Sciences; Bangor University; Gwynedd LL572UW UK
2. Centre for African Conservation Ecology; Nelson Mandela University; Port Elizabeth South Africa
3. Global Trophic Cascades Program, Department of Forest Ecosystems and Society; Oregon State University; Corvallis OR 97330 USA
4. Centre for Biodiversity and Restoration Ecology, School of Biological Sciences; Victoria University of Wellington; New Zealand
5. Research Institute for the Environment and Livelihoods; Charles Darwin University; Darwin Australia