Kevin J. Zimmer: Research Associate, Los Angeles County Museum of Natural History, USA. Bruno A. Walther: Post-doctoral researcher, Zoological Museum, University of Copenhagen, Denmark. Stephanie J. Tyler: Monmouthshire, Wales. Angela K. Turner: School of Biology, University of Nottingham, Nottingham, England. José G. Tello: Graduate Student, Division of Birds, Field Museum of Natural History and Department of Biological Sciences, University of Illinois, Chicago, USA. Fracisco Suárez: Departamento de Ecología, Universidad Autónoma de Madrid, Spain. David W. Snow: British Museum (Natural History), Tring, Hertfordshire, England. Edwin Scholes III: Visiting Fellow, Cornell University Museum of Vertebrates, Cornell University, New York, USA. Dr Peter G. Ryan: Senior Lecturer, DST/NRF Centre of Excellence at the Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa. Mark B. Robbins: Ornithology Division, University of Kansas Natural History Museum, Lawrence, Kansas, USA. Jason A. Mobley: Research Associate, Cornell Laboratory of Ornithology, Cornell University, New York, USA. Alan Lill: Associate Professor, Monash University, Victoria, Australia. Daniel J. Lebbin: Graduate Research Assistant, Department of Ecology and Evolutionary Biology, Cornell Laboratory of Ornithology, Cornell University, New York, USA. Gary M. Langham: Graduate Research Assistant, Cornell Laboratory of Ornithology Post-doctoral Fellow, James Cook University, Queensland, Australia, and University of California, Berkeley, California, USA and President, Neotropical Grassland Conservancy. Eduardo de Juana: Departamento de Biología Animal, Universidad Complutense de Madrid, Spain. Leo Joseph: Chair, Department of Ornithology, Academy of Natural Sciences, Philadelphia, Pennsylvania, USA. Peter A. Hosner: Research Assistant, Cornell Laboratory of Ornithology, Cornell University, New York, USA. Brian J. Gill: Auckland War Memorial Museum, Auckland, New Zealand. John W. Fitzpatrick: Director, Cornell Laboratory of Ornithology, Cornell University, New York, USA. Andrew Farnsworth: Graduate Research Assistant, Department of Ecology and Evolutionary Biology, Cornell Laboratory of Ornithology, Cornell University, New York, USA. Paul Donald: Senior Research Biologist, Royal Society for the Protection of Birds, Sandy, England. Alan Danks: Regional Leader Nature Conservation, Department of Conservation and Land Management, Albany, Western Australia. Benjamin M. Clock: Assistant Curator of Visual Media, Macaulay Library, Cornell Laboratory of Ornithology, Cornell University, New York, USA. Isabel C. Caballero: Graduate student, Division of Birds, Field Museum of Natural History and Department of Biological Sciences, University of Illinois, Chicago, USA. Michael Brooke. Kimberly S. Bostwick: Curator of Birds and Mammals, Cornell University Museum of Vertebrates, and Research Associate, Department of Ecology and Evolutionary Biology, Cornell University, New York, USA. John M. Bates: Associate Curator of Birds, Field Museum of Natural History, Chicago, USA. Richard C. Banks: Zoologist Emeritus, USGS Patuxent Wildlife Research Center, Laurel, Maryland, USA and Research Associate, National Museum of Natural History, Washington, DC, USA. P. Alström.