Impacts of a hydroelectric power plant on the bat community in central Brazil

Hydroelectric power plants are the principal source of electricity in Brazil. Small hydroelectric plants (SHPs), which generate less than 30 MW, are important components of the national grid, and have been installed in the country at an increasing rate over the past 20 years. Operations of this type are regulated by environmental agencies, which require preliminary studies of environmental impact and posterior monitoring for the mitigation of potential impacts. The present study evaluated the impact of a SHP on the structure and dynamics of the local bat community in central Brazil. The study was based on the capture of bats in mist nets during eight field campaigns, four of which were conducted prior to the impoundment of the river, and four after the formation of the reservoir. Seventeen bat species were identified. The occurrence of species shifted following the impoundment, reflecting considerable changes in the structure of the local bat community caused by the installation of the dam, with negative effects on both species richness and bat abundance. The study also discusses specific aspects of the impacts of the dam on the different bat guilds.