山西汾西县扁桃林北社鼠的种群年龄结构分析

Analysis on Age Structure of Niviventer confucianus Populations of Almond Forest in Fenxi County of Shanxi Province

采用捕鼠笼和捕鼠夹每月捕鼠后,按月份收集北社鼠头骨制成标本,以头骨左侧第三上臼齿(M3)的生长与磨损情况进行年龄鉴定划分4个年龄组,用SPSS 13.0软件对北社鼠的年龄组成进行χ2检验,以研究北社鼠的种群年龄结构及其季节变动情况。结果表明,北社鼠的种群幼年鼠出现在5—11月,高峰月份7月和8月的数量分别占种群数量的47.73%和39.58%;北社鼠亚成年组主要出现在7—12月,9、10、11月数量分别占种群数量的34.78%、51.28%和55.88%;9月北社鼠的种群幼年组、亚成年组、成年组数量基本一致,10—11月亚成年组鼠数量超过成年组鼠;山西汾西县扁桃林北社鼠种群在不同月份其年龄结构不同,年龄组成的月际间更替明显。9—11月,当年鼠(幼年组鼠与亚成年组鼠之和)达到种群总数的60%以上,种群完成新老更替。

In this study,the age structure and seasonal variation of Niviventer confucianus populations were investigated.Mice were caught monthly by using the cage-traps and clip-traps,and then the skull of mice were made into specimen.The growth and wear of the third upper molar(M3)on the left side of the skull were used to identify,and then four age groups were classified.The age composition of Niviventer confucianus was analyzed by theχ2 test.The results showed that the juvenile mice of Niviventer confucianus occurred from May to November,and their occurrence peaked to 47.73%and 39.58%in July and August,respectively.The sub-adult mice occurred from July to December,and their occurrence peaked to 34.78%,51.28%and 55.88%in September,October and November,respectively.In September,the populations of juvenile group,sub-adult group and adult group of Niviventer confucianus population were similar.In October and November,the quantity of sub-adult group exceeded that of adult group.The age structure of Niviventer confucianus population was different with months,and the inter-monthly alternation was observed in Fenxi county,Shanxi province.From September to November,when the sum of juvenile mice and sub-adult mice reached more than 60%of the total population,Niviventer confucianus populations completed the replacement of new and old.