Ultrasonic Acoustic Deterrents Reduce Bat Fatalities at Wind Turbines

Wind turbines are known to cause bat fatalities worldwide, and, as a result, pose a risk for species extinction. Ultrasonic acoustic deterrents (hereafter deterrents), as a bat impact reduction strategy, are a potential solution; however, little field testing exists. Our objective was to assess effectiveness of a newly developed deterrent for reducing bat fatalities at a wind energy facility in south Texas. We searched daily wind turbines equipped with deterrents and control wind turbines from 31 July through 30 October in 2017, and assessed effectiveness of deterrents with generalized linear mixed models. After completing 2,560 searches, we identified 627 bat fatalities comprised of 8 species and 1 species group. Our results indicate deterrents significantly reduced overall bat fatalities for Lasiurus cinereus and Tadarida brasiliensis. However, deterrents were not effective for Lasiurus [Dasypterus] intermedius. Based on this, deterrents represent a potential impact reduction strategy for some species of bats, but research is still warranted to improve the species-specific effectiveness.