四川短尾鼩不同体重个体分布及种群繁殖力变化

Individual Distribution in Different Body Weight and Population Reproductive Capacity of Anourosorex squamipes

对贵州省大方县1996～2012年采集的134只四川短尾鼩体重进行统计分析，结果表明：四川短尾鼩体重最低为12．20g，最高达48．00g，平均体重为（31．12±6．48）g，其雌、雄个体体重分布均呈常态分布，个体体重主要分布在22．1～40．0g之间，占总兽类数的85．07％，是活动能力较强的个体。四川短尾鼩达到性成熟的体重界线为22．0g，怀孕个体最低体重为26．00g，睾丸下降个体最低体重为23．80g，随着个体的增长，体重的增加，种群繁殖力不断增强，体重达30．0g以上时，种群繁殖力迅速增加，平均怀孕率、睾丸下降率和繁殖指数分别为43．75％、80．95％和1．53，说明体重达30．0g以上个体大部分已达到性成熟，是参与繁殖的主要个体。

The body weights of 134 Anourosorex squamipes have been analyzed from 1996 to 2012 in Dafang, Guizhou Provence. The results indicated that the minimum body weight was 12.20 gram, the maximum was 48.00 gram and the average was 31.12 ±6. 48 gram. Male and female body weight presented normal distribution. The body weight mostly ranged from 22. 1 gram to g0. 0 gram, which is 85.07% of the total, with stronger ability of the individual activities. The sexual maturity line was 22. 0 gram. The minimum body weight of pregnant Anourosorex squamipes is 26. 00 gram, and the minimum body weight of Anourosorex squamipes whose testicle descend is 23.80 gram. Along with the growth of individual quantity and body weight, population reproductive capacity enhanced continually. The rats began to propagate when their body weight reach 30. 0 gram, with the average pregnancy rate, testicular descent rate and reproduction index was 43.75% , 80. 95% and 1.53% , respectively. It showed that rat mostly reach sexual maturity when its body weight reach 30. 0 gram. It＇s the main reproduction contributor.