Bat activity at different wind facilities in Northwest Germany

To identify driving factors of bat activity as measured by the contacts, we perforrmed a general linear model analysis (GLM). Bat contacts were specified as dependent variable of the model; wind-turbine dimensions, weather data and location parameters were specified as independent variables of the model. The dependent variable was log-transformed x' = ln(x+1) prior to analysis. Non-linear terms of weather data were included to allow for representation of a hump-shaped relationship between weather and bat contacts in the model. Backward selection of variables was applied to ensure that the final model was exclusively built from significant variables. The analysis was performed using the Statistica for Windows package (StatSoft Inc., Tulsa, OK, USA) .