1 1Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 Sichuan China.
2 2University of Chinese Academy of Sciences, Beijing, 100049 China.
3 3Ministry of Education Key Laboratory for Tropical Plant and Animal Ecology, College of Life Sciences, Hainan Normal University, Haikou, 571158 Hainan China.
4 4Department of Psychology, University of Maryland, College Park, MD 20742 USA.