针毛鼠种群年龄组的划分标准及其繁殖力

Classification Standard and Fecundity of Population Age Groups in Rattus fulvescens

为丰富国内针毛鼠的种群生态学研究资料并为其预测预报提供科学依据,利用1984-2013年贵州省余庆县、岑巩县、凯里市和雷山县的稻田与旱地耕作区鼠情监测中捕获的针毛鼠数据,对其种群年龄组的划分标准及繁殖力进行研究。结果表明：针毛鼠平均体重为（70.12±23.60）g,根据体重的频次分布特征,参照其繁殖状况,将针毛鼠种群年龄划分为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≤35.0g,亚成年组（Ⅱ）35.1~55.0g,成年Ⅰ组（Ⅲ）55.1~75.0g,成年Ⅱ组（Ⅳ）75.1~95.0g,老年组（Ⅴ）〉95.0g。不同年龄组形态特征具有一定变化,随着种群年龄的增长而不断增加。雌鼠怀孕率和胎仔数、雄鼠睾丸下降率和繁殖指数随着种群年龄的增长而增加。成年Ⅰ组、成年Ⅱ组和老年组为该鼠的主要繁殖群体。不同季节种群年龄组成变化明显。

The classification standard and fecundity of different population age groups in R.fulvescens were studied by analyzing the data collected from R.fulvescens monitoring of rice field and dry land cultivation area in Yuqing,Cengong,Leishan counties and Kaili city during 1984-2013 to enrich research data of R.fulvescens population ecology in China and provide the scientific basis for prediction and forecast of R.fulvescens.The results showed that the average body weight of R.fulvescens is 70.12±23.60 g and 5 age groups can be divided according to distribution characteristics of body weight frequency and reproduction status.The body weight classification standard of young group,sub-adult group,adult groupⅠ,adult group Ⅱ and older group is ≤35.0 g,35.1~55.0 g,55.1~75.0 g,75.1~95.0 gand 〉95.0 g respectively.The morphological characteristics of different age groups varies with increase of population age.The female pregnant rate,litter size,male testicular descent rate and reproductive index increase with increase of population age.Main reproductive populations are group Ⅰ,adult group Ⅱ and older group. The population age composition varies in different seasons obviously.