ACKNOWLEDGMENTS

We greatly appreciate all the individuals involved in the capture and banding of A. erythropus that generated the data for this study. We recognize the contributions of staffs from East Dongting National Nature Reserve of China.
Funding statement : This study is supported by National Key Research and Development Program of China (2017YFC0405300). Logistic and transportation support to surveys in Chukotka was provided by Chukotka Gold Mining Co, a subsidiary of Kinross Gold.
Ethics statement : All field methods used in this study were approved by the Forestry Department of Hunan Province of China under scientific research license (No.11 Xiang Forest Protection (2014)). Field research was conducted with permission from the Bureau of East Dongting National Nature Reserve.
Author contributions : L.G., D.S. and Z.Q. developed the study design, D.S., G.D., S.V. participated the breeding surveys, and T.H. and L.J. participated in the tracking at wintering sites, all authors were involved in analyses and producing figures, D.S., Z.Q. L.W. and T.H. drafted the manuscript, P.B and L. W. edited the manuscript, P.B. L.W. and Z.Q. organized submission materials and revised the manuscript.
Data deposits : All data for analysis is available in Dryad.