关键词: 北山羊, 集群大小, 集群类型, 天山中部

Abstract: We studied group sizes and types of Asiatic ibex（Capra sibirica）in the middle Tien Shan from October 2013 to September 2014. Groups were classified as male, ewe-lamb, mixed groups, and solitary sheep. A total of 6327 individuals belonging to 497 groups were observed, with a mean group size of 12.93±0.65. The largest groups included 100 individuals and the smallest groups were solitary sheep. Mean group size was 14.83±1.35 in spring, 14.16±1.65 in summer, 15.17±1.69 in autumn, and 9.32±0.74 in winter. The average group size changed significantly between winter and the other three seasons. The maximum mean group size was mixed groups, followed by ewe-lamb and then male. Kruskal-Wallis H test showed significant differences in group size of each group type. Group with 2-7 individuals, 8-20 individuals and >20 individuals accounted for 41.05%, 32.80% and 17.71%, respectively. Ewe-lamb groups were the most frequently encountered，followed by mixed, male, and solitary sheep. The frequency with which we observed social groups varied by season. Research shows that Asiatic ibex composed of mixed groups in estrus and living in separate groups except for breeding season. Affected by the external environment and physiological characteristics, the group size, group type will change with the seasons.

Key words: Capra sibirica, Group size, Group type, Middle Tien Shan