1. Department of Ecology and Genetics, University of Aarhus, Building 540, Ny Munkegade, DK‐8000 Aarhus C, Denmark
2. Department of Applied Biology, Estación Biológica Doñana, CSIC, Pabellón del Perú, Avda. Maria Luisa, s/n 41013 Seville, Spain
3. Department of Wildlife Ecology and Biodiversity, National Environmental Research Institute, Kalø Grenåvej 14, DK‐8410 Rønde, Denmark
4. Istituto Nazionale per la Fauna Selvatica, via Ca' Fornacetta 9, I‐40064 Ozzano Emilia (Bo), Italy
5. Danish Institute for Fisheries Research, Department of Inland Fisheries, Vejlsøvej 39, DK‐8600 Silkeborg, Denmark
6. Department of Genetics, University of Groningen, Kerklaan 30, NL‐9751 NN Haren, The Netherlands