安徽淮北农区三种鼠的种群数量动态与年龄结构的关系

RELATIONSHIP OF THE POPULATION DYNAMICS AND THE AGE COMPOSITION OF THREE RODENTS IN RURAL DISTRICTS OF NORTHERN HUAIHE RIVER, ANHUI

本文对安徽省淮北农业区的黑线姬鼠、大仓鼠和黑线仓鼠的种群数量及与年龄组成变化的关系进行探讨。结果表明,其各鼠的年龄组成在每年的不同时段内的变化有一定的规律:各鼠主要繁殖群体的年龄组也是有区别的,如黑线姬鼠和黑线仓鼠主要是成年Ⅱ组,大仓鼠主要是成年Ⅰ组。如果种群中幼年组+亚成年组+成年Ⅰ组的比例高时,则当年数量就可能较高,如果种群中成年Ⅱ组和老年组的比例较高时,当年数量则低。

This paper deals with the relationship of the population dynamics and the age composition of striped field mouse (Apodemus agrarius), ratlike hamster (Cricetulus trit-on) and striped hamster (Cricetulus barabensis). The specimens of three rodents were collected in Northern Huaihe River, Anhui Province during 1982 to 1988, and with the growth and the wear of upper molar as the age criteria , the specimens were divided into five age groups. juvenile (Ⅰ), subadult (Ⅱ), adult I(Ⅲ) adult I (Ⅳ) and senior (Ⅴ). Analyses showed that the age composition of each species in the different seasons varied regularly. The proportions of the adult I ( or the senior ) in the age composition were very high before the beginning of the reproductive period of them, and after the reproductive period owing to the new members from breeding uninterrupted puting in the population, that of each group in the composition correspondingly varied with the changes of age in the population. This proportions in the age composition varied from year to year too. In addition, the major colonies of reproduction in the population were the adult I in striped field mouse and striptod hamster , and the adult I in ratlike hamster. As for the relationship between the population dynamics and the age composition of the population of three rodents, the annual numbers was higher when the proportions of the age groups( Ⅰ + Ⅱ + Ⅲ) was higher, and lower when that of the age groups (Ⅳ + Ⅴ) were higher.