Acknowledgments
The research was logistically supported by the Uryu Research Forest,
Hokkaido University for fieldwork. We acknowledge staff members at Uryu
Research Forest, Hokkaido University, including Tetsuro Nakaji, Rei
Sakai, Yuko Hara, and Tohru Miyazaki. We thank many student volunteers
who assisted fieldworks. This study was financially supported by KAKENHI
Grant Number 21H04784 to H.U. from the Japan Society for the Promotion
of Science. Our work conforms to the guidelines for the proper conduct
of animal experiments in Japan. Field survey of aquatic animals was
approved by the fishery and forestry department of Hokkaido (ID 610).