1. Ministry of Education, Key Laboratory of Biodiversity Science and Ecological Engineering, Department of Ecology, College of Life Sciences, Beijing Normal University , Beijing 100875 , China
2. Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in the Giant Panda National Park, China Conservation and Research Center for the Giant Panda , Sichuan 623004 , China
3. School of Computer and Information Technology, Beijing Jiaotong University , Beijing 100044 , China
4. Beijing Key Laboratory of Captive Wildlife Technology , Beijing Zoo, Beijing 100044 , China
5. Department of Biology, Irving K. Barber Faculty of Science, The University of British Columbia , Okanagan Campus, Kelowna, BC , Canada