Kjell Danell1,
Roger Bergström2,
Margareta Stéen3,
Leif Mattsson4,
David5
- Swedish University of Agricultural Sciences, Umeå, Sweden
- Gropgränd 2A, 753 10 Uppsala, Sweden
- Box 7053, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden
- Släne 41, 432 99 Skällinge, Sweden
- Kent, Great Glen Wildlife, Sherren, Harray, Orkney, England