我国黄羊种群结构及动态趋势的研究

随机抽取1988年12月猎于内蒙古西旗的1026只黄羊,对其种群结构的研究表明:1988年黄羊种群可划分成8个年龄组,当年出生的幼体比重较大,占39.7％;具繁殖能力的雌体数占24.95％;4.5岁以上年龄组个体数占12.7％;是典型的增长型年龄结构。种群全体、2.5、3.5、5.5岁以上年龄组的性比((?)/♀♀)与1:1差异显著(P<0.05),此结果与1979年差异较大。生命表和死亡率曲线表明:种群有3个死亡高峰,分别发生在0.5、3.5和6.5岁以上年龄组。1979年和1988年黄羊种群的净生殖率(R。)分别为1.1335和0.864;1988年雌性开始繁殖的年龄有比1979年提前的趋势。30年来黄羊种群数量明显减少,分布区迅速缩小。由于黄羊的繁殖能力强和增长型的年龄结构,只要加强保护和管理,恢复扩大种群是可能的。

A STUDY ON POPULATION STRUCTURE AND DYNAMIC TREND OF MONGOLIAN GAZELLE IN CHINA

The study on randomly sampled 1026 Mongolian gazelle(Procapra gutturosa)from Western Banner,Hulun-Beier grassland,in December 1988 has been done.The population in 1988 could be classified into 8 age groups, the proportion of new born animals is high(39.7%),reproductive female is 24.95%,above 4.5 year-old groups is 12.7%,it is a typical rapidly increasing age structure.Comparing with 1:1 there are significant difference in the sex ratio( )of the total population, 2.5,3.5 and over 5.5 year--old age groups,the result is very differ from that in 1979.According to the life table and death rate curve there are three mortality peaks happened at 0.5,3.5 and over 6.5 year-old age groups.The net reproductive rate(R0)of the population in 1979 and 1988 are 1.1335 and 0.864 respectively.There is a trend of sex-maturity age in 1988 ealier than that in 1979. The population size decreased obviously and distribution area shrinked quickly during past 30 years.With high reproductive capacity and increasing age structure, the population restoration of Mongolian gazelle is possible if the protection and management are improved.