长爪沙鼠的肝毛细线虫感染率与鼠类及猛禽密度的关系

为研究鼠类密度和猛禽密度对鼠类肝毛细线虫(Capillaria hepatica)感染率的影响,作者于2004年7月在内蒙古锡林郭勒盟阿巴嘎旗北部和东乌珠穆沁旗西南部典型草原草场选取了14个实验样地,采用洞口计数法(四分之一圆面积法)调查估计各实验样地内长爪沙鼠(Meriones unguiculatus)密度,同时采用夹线调查法捕获鼠类样本,进行常规解剖获取肝毛细线虫的感染数据。采用目测计数法统计猛禽的出现频次,并以其出现频次作为猛禽的相对密度指标。实验样地共捕获长爪沙鼠1 058只,观察到鹰隼类活动69只次。数据分析结果表明,长爪沙鼠肝毛细线虫感染率与鼠类密度之间存在极显著的正相关关系(P0.01,R~2=0.926),长爪沙鼠肝毛细线虫感染率与猛禽密度之间亦存在极显著的正相关关系(P0.01,R~2=0.853)。该结果说明,长爪沙鼠是肝毛细线虫的主要宿主,鼠类密度和猛禽密度的升高均会增加长爪沙鼠肝毛细线虫感染率,猛禽密度和鼠类密度之间还存在叠加效应,猛禽的捕食作用会加快肝毛细线虫病的传播周期,加重肝毛细线虫病疫情。

Relationship between Infective Characters of Capillaria hepatica in Meriones unguiculatus and the Density of Rodents and Raptors

To study the relationship between infective characters of Capillaria hepatica in Mongolian Gerbil (Meriones unguiculatus) and the density of rodents and raptors, this research selected 14 experimental areas in Abagaqi and Dongwuzhumuqinqi in Xilinguole League, Inner Mongolia during July 2004. We used the number of burrow method to efficiently investigate the density of M. unguiculatus. Standard killing trap method was adopted to capture rodent samples and we observed and counted the density of raptors within 3 km2 over the experimental area at the same time. Captured rodents were subsequently dissected to check the infection of parasites. The regression analysis was used to analyze the data. Altogether 1 058 rodents were captured, and raptors were observed for 69 times (Table 1). As a result we found that the relationship between infection rate and rodent density was extremely significant (P < 0.01, R2 = 0.926), and so did the relationship between infection rate and raptor density (P < 0.01, R2 = 0.853). The infection rate would increase with the rising of rodent density and raptor density. Moreover, there is a significant duplicate effect between rodent density and raptor density. The predation of raptors would shorten the diffusion period of C. hepatica and aggravate the hepatic capillariasis.