1. Department of Clinical Sciences Swedish University of Agricultural Sciences SE‐75007Uppsala Sweden
2. Department of Animal Ecology Evolutionary Biology Centre (EBC) Uppsala University Norbyvägen 18D SE‐75236Uppsala Sweden
3. Department of Biosciences Metapopulation Research Centre University of Helsinki PO Box 65 FI‐00014Helsinki Finland
4. Department of Biology Centre for Biodiversity Dynamics Norwegian University of Science and Technology N‐7491Trondheim Norway
5. Department of Evolutionary Biology Evolutionary Biology Centre (EBC) Uppsala University Norbyvägen 18D SE‐75236Uppsala Sweden