Previous Articles     Next Articles

STUDIES 0N THE P0PULATION ECOLOGY OF SULPHUR BELLIED RAT

ZHANG Jie   

  • Online:2006-07-29 Published:2007-09-13

社鼠种群生态研究

张洁   

  1. 中国科学院动物研究所

Abstract: In the period of 1983- 1986,the author had carried out the study on the population ecology of Sulphur Bellied Rat Rattus niviventer in Xishan area of Beijing。A totalnumber of 870( 464,406)rats were captured as samples.These sample rats were divided into five age groups according to their body weight excluding viscera . Results showed that there were obvious seasonall disparities in age composition. The changes of the age composition were mainly caused by the changes of the reproductive behavior.Studies on the sex ratio represented that the proportion of female rats were generally higher than that of male in young and sub—adult groups.
The sulphur bellied rats started to breed from March to April, and most of them finished the breeding in September.Occasionally some individuals were found to be pregnant in October to December.The weight of the testis of the matured male rats were more than 0.8g.Females became matured at the age of 3— 8 months after being born, and usually started to breed only after overwintering.Most of females bred two foetus,but some of them bred once ,only a little individuals were found to breed three foetus in a year. The average of litter sizes for one foetus were 5.20. The number of litter sizes varied between 4.78—5.55.
The ecological life of sulphur bellied rat was 1.5 years or more.Some individuals participated breeding activities in two years.There were obvious seasonal difference in the number of population owing to the effect of reproduction and weather.The pattern of the changes in population was basically“S" type.The sulphur bellied rats inhabit onlv in mountain areas.They had not been found in plain.

Key words: Sulphur bellied rat, Population ecology, Reproduction, Population age composition, Population dynamics, Body weight excluding viscera

摘要: 1983-1987年在北京西山研究了社鼠的种群生态学。共捕获标本870只。用胴体重方法划分5个年龄组。种群年龄组成, 随季节而有变化。年龄锥体有季节和年度差异。雌雄性比亦有年度变化。在多数年份中, 幼体和亚成体的雌性比例高于雄性。社鼠一般在3— 4月开始繁殖, 9月基本结束,10月见到个别孕鼠。雄性个体性成熟时的睾丸重量在0.8克以上,雌性产仔数平均为5.20。多数雌体一年繁殖2次,个别可繁殖3次。生态寿命约一年半或更长一些。有些雌体参加两年的繁殖括动。社鼠的种群数量,有明显的季节和年度变化。

关键词: 社鼠, 种群生态, 繁殖, 年龄组成, 种群数量变动, 胴体重