Analysis on changes of rodents density and species in Hubei-Yichang section of three gorges reservoir area before and after impoundment

Objective To understand the changes of rodents density and species in three gorges reservoir area in Yichang before and after impoundment and to take timely measures. Methods Night trap method was used in the study of rodents density and species. Results The density of rodents showed a downward trend before impoundment, which declined from 7.14% in 1997 to 0.33% in 2002 for indoor rodents, and from 1.74% in 1997 to 0.84% in 2002 for outdoor rodents. However, the density of rodents showed a upward trend after impoundment, which increased from 0.68% in 2003 to 5.51% in 2008 for indoor rodents, and from 0.22% in 2003 to 0.97% in 2008 for outdoor rodents The density of indoor rodents was higher than that of outdoor rodents. The predominant species of indoor rodents were the Rattus norvegicus, Mus musculus before impoundment and Rattus flavipectus after impoundment. The predominant species of outdoor rodents were Rattus norvegicus, Mus musculus before impoundment and Rattus flavipectus, Apodemus agrarius and Mus musculus after impoundment. Conclusion The density of rodents in three gorges reservoir area in Yichang before and after impoundment changed significantly. The density of rodents showed a downward trend before impoundment, and the density of rodents showed a upward trend after impoundment. However, both the species and the predominant species of rodents changed before and after impoundment, indicating the necessity of intensive surveillance of rodents and provide evidence for the effective control of insect-borne infectious diseases.