Using Ultraviolet Light to Deter Bats from Wind Turbines - Short Science Summary

One hypothesis seeking to explain why bats collide with wind turbines is that bats, while relying on visual cues during open-air flight, mistake turbine silhouettes as trees. As a result, bats become attracted to the wind turbine in anticipation of foraging, roosting, and/or mating opportunities. As a technique to disrupt this attraction, a series of studies (including ongoing research) have investigated whether illuminating wind turbines with ultraviolet (UV) light (visible to bats but not humans) would make them visually distinct from trees to the point that bats would no longer confuse the two. During tests in a natural setting, bats appeared to exhibit a slightly negative response to UV-lit trees; however, during testing at wind turbines, there was no significant difference in bat activity between UV-lit and non-UV-lit turbines. At present, there is no strong evidence that UV illumination either deters (or attracts) bats, and existing evidence remains inconclusive. Current and future research should investigate the efficacy of UV illuminance with study designs that focus on increased sample sizes while monitoring for any potentially unanticipated negative effects to the environment when adding stimuli such as UV lights, which may, for example, attract insects.