1. a Department of Biological and Environmental Sciences , PO Box 35, University of Jyväskylä, FI-40014, Jyväskylä, Finland
2. b Finnish Forest Research Institute, Vantaa Research Unit , PO Box 18, FI-91301, Vantaa, Finland
3. c Department of Ecology , Swedish University of Agricultural Sciences , PO Box 7044, SE-750 07, Uppsala, Sweden
4. d Centre of Excellence in Evolutionary Research, Department of Biological and Environmental Sciences
5. e Natural History Museum , PO Box 35, University of Jyväskylä, FI-40014, Jyväskylä, Finland
6. f Natural History Museum , PO Box 1172, University of Oslo, NO-9318, Oslo, Norway
7. g Norwegian Institute for Nature Research (NINA) , Gaustadalléen 21, NO-9349, Oslo, Norway