Acknowledgements This study was supported by National Natural Science Foundation of China (31572290, 31770568, and 31770427), Youth Innovation Promotion Association CAS (2015304), National Key Research and Development Plan (2016YFC0503303), China Scholarship Council (No. 201706775008), and the project from Qinghai Provincial Communication Department (31118022). We thank M. B. C Andrade for the valuable discussion on this research. All animal handlings were in accordance with the Law of the People’s Republic of China on the Protection of Wildlife and approved by the Animal Care Committee of Chengdu Institute of Biology, Chinese Academy of Sciences.