关键词: 子午沙鼠, 种群数量, 怀孕率, 繁殖指数

Abstract: Objective To study population dynamics of little Chinese jird (Meriones meridianus) and its affecting elements. Methods The population dynamics of little Chinese jird was investigated by rectilinear-trap-day method in middle ten days of each month from April to October during 1991-1998. Results There are ten species of rodents in Dalate County during 1991-1998. Northern three toed jerboa (Dipus sagitta),desert hamster(Phodopus roborovskii),little Chinese jird and striped hamster(Cricetulus barabensis) accounted for over 10%,respectively.The seasonal fluctuation has two peaks every year.In 1991-1998,the population dynamics fluctuated with low valley(1991),increase(1992),peak(1993-994),decrease(1995) and low valley(1996-1998)among 8 years. Annual capture rates are all under 2%,s(of logx,x=population density ofM.meridianus)<0.5. Between the number ofM.meridianusand pregnant rate,r=|-0.758|>r_0.05=0.754; Between the number and repregnant rate,r=0.827>r_0.05=0.811; Between capture rate in Oct.and capture rate in Apr. next year,r=0.759>r_0.05=0.754,df=5; Between the number of the jird and the number of D.sagitta,P.roborovskiiandC.barabensis,r=0.662(0.05=0.707),0.762(>r_0.05=0.707)and0.498(r_0.05=0.707) respectively. Conclusion D.sagitta,P.roborovskii,M.meridianusandC.barabensisare the dominant rodent species in Dalate County in 1991-1998.The population number is maximum in March and in July. The annual fluctuation is not periodical. The important elements of population dynamics were the pregnant rate,the repregnant rates,reproduction index,the capture rate and the population number of other species (D.sagitta,P.roborovskiiandC.barabensis).