1. CEFE‐CNRS, 1919 Route de Mende, 34293 Montpellier Cedex 5, France,
2. Arctic Centre, University of Lapland, P.O.Box 122, FIN‐96101 Rovaniemi, Finland,
3. ONCFS, 8 impasse Champ Fila, 38320 Eybens, France,
4. Finnish Game and Fisheries Institute, Oulu Game and Fisheries Research, Tutkijantie 2 A FIN‐90570 Oulu, Finland,
5. Zoological Institute, Conservation Biology, University of Bern, Baltzerstrasse 6, CH‐3012 Bern, Switzerland,
6. CBGP‐INRA, Campus International de Baillarguet, CS 30016, 34988 Montferrier‐sur‐Lez Cedex, France