1. Centre for Biodiversity Dynamics, Department of Biology Norwegian University of Science and Technology Trondheim Norway
2. Ecology and Evolutionary Biology, School of Biosciences University of Sheffield Sheffield UK
3. British Trust for Ornithology Thetford UK
4. Department of Biological and Environmental Science University of Jyväskylä Jyväskylä Finland
5. Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences University of Helsinki Helsinki Finland