1. Laboratory of Wildlife Ecology, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
2. Department of Basic Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
3. Primate Research Center, Kyoto University, Inuyama, Japan
4. Botanic Garden, Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan
5. Nature Conservation Branch, Division of Environmental Conservation, Shari Town Office, Shari, Japan