Wind energy has been the fastest-growing renewable energy source in the world. Studies have estimated bat fatalities at wind facilities, but direct comparisons of results is difficult and can be misleading due to numerous differences in protocols and methods used. We had a unique opportunity to compare fatality estimates from three wind facilities in southeastern Wisconsin. These three facilities are located within two neighboring counties with similar land use and land cover, used similar post-construction study methodologies, have turbine models that are close in size and nameplate capacity, and all became operational within seven months of each other. Our objectives were to analyze bat mortality data across all three wind facilities to: 1) examine species composition; and 2) investigate whether select structural, habitat, and landscape features influence mortality at a fine and broad scale. Corrected estimates of bat mortality were higher than reported in most other previous research in Midwestern agricultural lands in the United States. Similarities within the data were shared by all three wind facilities, but differences across them included species composition of bat mortalities and raw and corrected number of bat carcasses recovered. Our analysis suggested that select habitat and landscape features were among the predictor variables that explained bat mortality at the broad scale. Given heterogeneity in mortality estimates within the upper Midwest region, we recommend that individual wind facilities conduct project-specific.
Senior Project Manager Mike Sponsler is a co-author of this paper published by the Museum and Institute of Zoology, Polish Academy of Sciences.