Surveillance of small mammals in drawdown area in the Three Gorge reservoir area,2010

Objective To understand the species and density of small mammals in drawdown area in the Three Gorge reservoir area and provide evidence for the control of rodents related diseases in the reservoir area. Methods Four surveillance sites were established in typical drawdown area in upper, middle and down streams of the reservoir area. For each surveillance site, 100 traps were placed at different altitude. The surveillance was carried out during the period when water subside from June to September. Results Four surveillance sites were established in Banan, Zhongxian and Kaixian counties of Chongqing, and in Zigui county of Hubei. In June 2010, a total of 1394 traps were placed and 31 small mammals were captured, the density was 2.22%. Apodemus agrarius was the predominant species (80.65%). Rattus tanezumi, Anourosorex squamipes and Rattus norvegicus were also found. In September, 891 traps were placed and 11 small mammals were captured, the density was 1.23%, and Rattus norvegicus and Anourosorex squamipes were the predominant species. The density in June was higher than that in September. Conclusion Small mammals might move into the drawdown area in the Three Gorge reservoir area, including some rodents species related to major zoonosis. It is necessary to conduct small mammals surveillance, especially the surveillance of rodents, in the period when water subside and conduct long-term prevention and control.