1. Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
2. Institute of Statistical Mathematics, Minato‐ku, Tokyo, Japan
3. Department of Wildlife Science, College of Bioresource Sciences, Nihon University, Kameino, Fujisawa, Japan
4. Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
5. Laboratory of Wildlife Ecology, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
6. Laboratory of Wildlife Ecology, Department of Life Science, Tunghai University, Taichung, Taiwan
7. Katsuraoka, Otaru, Japan