1. Laboratory of Biodiversity Science, School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
2. Abiko City Museum of Birds, Chiba, Japan
3. Shinshu Raptor Migration Research Group, Nagano, Japan
4. Satoyama Natural History Research Group, Chiba, Japan
5. Nagano Environmental Conservation Research Institute, Nagano, Japan
6. Raptor Conservation Center, The Ministry of the Environment, Yamagata, Japan
7. Faculty of Education, Shinsu University, Nagano, Japan