1. Environmental Futures Research Institute; School of Environment; Griffith University; Gold Coast Qld 4111 Australia
2. Natural Environments Program; Queensland Museum; Institute of Biodiversity and Ecosystem Research; P.O. Box 3300 South Brisbane Qld 4101 Australia
3. Institute of Biodiversity and Ecosystem Research at the Bulgarian Academy of Sciences; 2 Gagarin Street Sofia 1113 Bulgaria
4. Department of Zoology; Edward Grey Institute of Field Ornithology; University of Oxford; Oxford OX1 3PS UK