Acknowledgements
We thank help from Danish-Korean expedition team during the field seasons. The research has been conducted under permissions from the Greenland government and these permits include consideration and approval of fecal sampling for muskoxen (permission no. G16-074, C-17-4). The local ethics committee (Ministry of Industry and Mineral Resources, the Government of Greenland) specifically reviewed and approved the application for survey license on the use of biological resources for commercial and research purposes (in the following: Act on Biological Resources).