Bird and Bat Movement Patterns and Mortality at the Montezuma Hills Wind Resource Area

Birds and bats have become important factors in the siting and permitting of wind-energy facilities. Identifying methods to avoid, minimize, and mitigate bird and bat fatalities should help streamline wind energy permitting and reduce potential impacts to bird and bat resources. In this study, the authors conducted nighttime surveys to investigate the effectiveness of using horizontal/vertical radar, full-spectrum acoustic monitoring and night vision to determine nocturnal flight directions, passage rates, and flight altitudes of birds and bats at the Montezuma Hill Wind Resources Area in Northern California. Following nighttime surveys, daily carcass searches were conducted to assess fatality rates as a function of movement patterns in the wind resource area. In addition, the study explored relationships between bird and bat fatalities, relevant activity indicates, and the meteorological, landscape, and vegetation features of the study area.