四川羚牛繁殖期集群类型及海拔分布

Group Type and Distribution of Budorcas taxicolor tibetana in Rutting Season

为了探究繁殖期四川羚牛Budorcas taxicolor tibetana的集群特征,于2012年7月在四川唐家河国家级自然保护区开展了羚牛集群类型与海拔分布的研究。在唐家河的8条监测样线(总长度约68.2 km)上记录到39群469头次,其中完整辨别群结构的有36群448头次。群体可定义为独牛、家群、混合群、社群和公牛群,研究期间大部分集群(83.33%)的个体数≤20。除独牛和公牛群外,群体平均大小为(14.70±2.63)头,各类型集群大小差异显著(F2,27=8.463,P=0.001)。独牛、家群、混合群和社群的记录海拔之间存在显著的差异(F3,31=11.8488,P<0.001),除公牛群外羚牛集群的平均海拔为(2015.37±89.74)m。羚牛集群记录的海拔与集群大小之间存在显著的线性相关(y=29.76x+1465,R2=0.802,P<0.001)。研究认为,繁殖期集群类型的变化与繁殖活动密切相关,聚集群和独牛是繁殖期雄性成体不同繁殖策略的体现。

The group type and distribution of Sichuan takin （Budorcas taxicolor tibetana） in breeding season were investigated in Tangjiahe National Nature Reserve in July 2012. A total of 39 groups with 469 individuals were recorded in 8 line transects with the total length of 68.2 kin. Age and sex information of 36 groups with 448 individuals were well-documented. The group types could be defined as solitary, adult males group, family group, mixed group and social group. The size of majority groups （83.33%） were lower than 20 individuals during the observation. Except the solitary and adult male group, the mean group size was 14. 70 ＋ 2. 63, and significant difference was observed among family group, mixed group and social group （ F2,27 = 8.463, P = 0. 001 ）. Additionally, there was also significant difference among the distribution of solitary, family group, mixed group and social group （ F3,31 = 11. 8488, P 〈 0. 001 ） , and the mean elevation was 2015.37 m ＋ 89.74 m except the adult male group. Moreover, significant correlation between the elevation and group size （y = 29.76x ＋ 1465 ,R^2 = 0. 802 ,P 〈 0. 001 ） was determined by linear regression analysis. These results indicated that the variation between group type and group size of takin in breeding season was closely related to the reproductive behavior. The formation of group and solitary male adult might be caused by the difference of mating strategy.