Research on Population Age Structure of Anourosorex squamipes
作者单位：(1. 贵州省余庆县植保植检站，贵州余庆 564400；2. 贵州省大方县植保植检站，贵州大方 551600；3. 贵州省植保植检站，贵阳 550001；4.全国农业技术推广服务中心，北京 100026)
英文关键字：Anourosorex squamipes; age identification; division standard; reproduction; age structure
中文摘要：为给四川短尾鼩年龄鉴定提供科学合理的鉴定方法，对1996～2012年贵州省大方县捕获的134只四川短尾鼩(雌性86只，雄性48只)体重统计分析。结果表明：四川短尾鼩平均体重为(31.12 ± 6.48) g。根据体重的频次分配特征，参照其繁殖状况，将四川短尾鼩划分为5个年龄组，制定了各年龄组的体重划分标准：幼年组(Ⅰ)体重≤23.0 g，亚成年组(Ⅱ) 23.1～28.0 g，成年Ⅰ组(Ⅲ) 28.1～33.0 g，成年Ⅱ组(Ⅳ) 33.1～38.0 g，老年组(Ⅴ) >38.0 g。体重与胴体重、体长之间具有极显著的正相关关系，依据体重与胴体重的回归方程，制定了各年龄组的胴体重划分标准：幼年组(Ⅰ)胴体重≤15.0 g，亚成年组(Ⅱ) 15.1～19.0 g，成年Ⅰ组(Ⅲ) 19.1～23.0 g，成年Ⅱ组(Ⅳ) 23.1～27.0 g，老年组(Ⅴ) >27.0 g。不同年龄组体重、胴体重之间具有显著差异，随着种群年龄的增长而不断增加。不同年龄组种群繁殖力存在显著差异，随着种群年龄的增长，种群繁殖力不断增加，参与种群繁殖的主要群体为成年Ⅰ组、成年Ⅱ组和老年组，平均怀孕率为37.10%，平均睾丸下降率为72.00%，平均繁殖指数为1.39。种群年龄组成具有明显的季节变化。
英文摘要：In order to provide age identification method for Anourosorex squamipes, we analyzed the weight of 134 individuals (86 females and 48 males) which were captured in Dafang county, Guizhou province from 1996 to 2012. The results showed that the average weight of A. squamipes was 31.12 g± 6.48 g. According to the frequency distribution of weight and the reproductive condition, A. squamipes was divided into five age groups. We established the weight division criteria for each age group: youth group (Ⅰ) is less than 23.0 g, sub-adult group (Ⅱ) was 23.1 ~ 28.0 g, adult group Ⅰ (Ⅲ) was 28.1 ~ 33.0 g, adult group Ⅱ (Ⅳ) was 33.1 ~ 38.0 g and old group (Ⅴ) was more than 38.0 g. Significant positive correlations were observed between body weight, carcass weight and body length. On the basis of regression equation between body weight and carcass weight, we established the carcass weight division criteria for each age group: youth group (Ⅰ) was less than 15.0 g, sub-adult group (Ⅱ) was 15.1 ~ 19.0 g, adult group Ⅰ (Ⅲ) was 19.1 ~ 23.0 g, adult group Ⅱ (Ⅳ) was 23.1 ~ 27.0 g and old group (Ⅴ) was more than 27.0 g. There was significant difference in body weight and carcass weight among age groups. Body weight and carcass weight increased continuously with the growth of population age. Furthermore, there was significant difference in population reproduction across different age groups. With the growth of population age, population reproduction increased continuously. Adult group I, adult group II and old group were the main reproductive contributors. The study showed that the average pregnancy rate, average testicular descent rate and average reproduction index of these age groups were 37.10%, 72.00% and 1.39, respectively. Moreover, there was significant seasonal variation in the population age structure.