School of Life Science,East China Normal University,Shanghai 200062,China;
College of Wildlife Resources,Northeast Forestry University,Harbin 150040,China;
School of Life Science,East China Normal University,Shanghai 200062,China;
Helan Mountain National Nature Reserve,Yinchuan 750021,China;
School of Life Science,East China Normal University,Shanghai 200062,China;
School of Life Science,East China Normal University,Shanghai 200062,China;
blue sheep; Pseudois nayaur; habitat selection; principal components analysis; Helan Mountains;