1. Department of Breeding and Genetics, Danish Institute of Animal Science, Foulum, Denmark,,
2. Greenland Institute of Natural Resources, c/o Department of Artic Environment, National Environmental Research Institute, Tagensvej 135, DK‐2200 Copenhagen N, Denmark,,
3. Norwegian Polar Institute, P.O.B. 5072 Majorstuen, N‐0301 Oslo, Norway,,
4. Zoological Museum, University of Oslo, Sarsgate 1, N‐0562 Oslo, Norway