We investigated relationships between bats and wind turbines at the Mountaineer Wind Energy Center in Tucker County, near Thomas, West Virginia, and at the Meyersdale Wind Energy Center in Somerset County near Meyersdale, Pennsylvania. Our primary objectives were to compare results of daily versus weekly carcass searches, quantify bias corrections needed to more accurately estimate fatality, and recommend improved search protocols for bats. We also correlated bat fatalities detected during daily searches with the previous nights’ weather and turbine conditions, observed and quantified behavior of bats encountering moving and nonmoving blades at turbines with and without FAA lights, and evaluated the use of trained dogs to detect bat fatalities beneath turbines. Fatality searches were conducted at both sites between 31 July and 13 September 2004 with half of the turbines at each site searched daily and the other half weekly. Thermal imaging cameras were used to assess bat, bird, and insect activity at turbines only at Mountaineer from 2–27 August 2004.