Forest bat activity declines with increasing wind speed in the proximity of operating wind turbines

The increasing use of onshore wind energy is leading to an increased deployment of wind turbines in structurally rich habitats such as forests. Forest-affiliated bats, in turn, are at risk of colliding with the rotor blades. Due to the legal protection of bats in Europe, it is imperative to restrict the operation of wind turbines to periods of low bat activity to avoid collisions. However, bats have also been observed to avoid wind turbines over several hundred meters distance, indicating a displacement that cannot solely be explained by modifications to the habitat. This avoidance suggests a displacement of bats by indirect factors related to wind turbine operation, e.g., wake turbulences and noise emissions. Therefore, we investigated whether the activity of forest-affiliated bats is influenced by operation mode (on/off) under variable wind conditions along transects from 80 to 450 m distance to wind turbines. We divided recordings by foraging guild, i.e., either narrow-space (Myotis,..., Bat calls were recorded with automated ultrasonic recorders at increasing distances to wind turbines in forests. 12 study sites, 8 sampling periods between 2020 and 2021.
Wind turbine data was provided by the respective companies., Open commented R-script (R_analyses.Rmd) in RStudio and run it chunk by chunk., # Wind turbines operating at high wind speeds have a negative impact on the activity of forest bats

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Data set contains bat calls from 12 forests with wind turbines, recorded in increasing distance to turbines.
Further, it contains information on operation status and weather at the time of recording as well as data characterizing the habitat structure.
Based on this data set, we investigated how bat call activity is influenced by wind turbine operation at different weather conditions.
Our main finding: Bats of the narrow-space foraging guild (forest specialist) are decreasing activity with increasing wind speed, but only around operating wind turbines. This pattern suggests that avoidance behavior of bats towards wind turbines, which was observed in various recent studies, is caused by factors related to turbine operation, for example noise emissions.

## Description of the data and file structure

R_analysis_dryad.Rmd: Commented R-script. Use the R-script to load and analyze the da...