Apply textured coating to turbines
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Background information and definitions
It has been suggested that smooth surfaces, such as those found on wind turbine towers, may be misidentified by bats as water or clear flight paths due to their acoustic mirror properties (Russo et al. 2012, McAlexander 2013, Greif et al. 2017). Applying a textured coating could reduce bat collisions and fatalities. Behavioural experiments in flight rooms found that bats did not make contact with textured surfaces and approached them less often than smooth surfaces (Greif & Siemers 2010, Bienz 2015).
Bienz C. (2015) Surface texture discrimination by bats: implications for reducing bat mortality at wind turbines. MSc Thesis. Texas Christian University.
Greif S. & Siemers B.M. (2010) Innate recognition of water bodies in echolocating bats. Nature Communications, 1, 107.
Greif S., Zsebők S., Schmieder D. & Siemers B.M. (2017) Acoustic mirrors as sensory traps for bats. Science, 357, 1045–1047.
McAlexander C. (2013) Evidence that bats perceive wind turbine surfaces to be water. MSc Thesis. Texas Christian University.
Russo D., Cistrone L. & Jones G. (2012) Sensory ecology of water detection by bats: A field experiment. PLOS ONE, 7, e48144.
Supporting evidence from individual studies
A paired sites study in 2017 at a wind farm in an agricultural and wooded area in Texas, USA (Huzzen et al 2019) found that applying a textured coating to a turbine did not reduce the activity of four bat species or the number of bats observed compared to a conventional smooth turbine. Average hoary bat activity was greater at a textured turbine than a smooth turbine in one trial (textured: 2.7 calls/h; smooth: 0.3 calls/h) but did not differ significantly in the other (textured: 0.3 calls/h; smooth: 0.7 calls/h). Activity did not differ significantly between textured and smooth turbines in either trial for eastern red bats Lasiurus borealis (textured: 1.5–1.8 calls/h; smooth: 1.3–1.9 calls/h), tricolored bats Perimyotis subflavus (textured: 0.8–1.1 calls/h; smooth: 0.9–1.0 calls/h), or evening bats Nycticeius humeralis (textured: 1.0–1.5 calls/h; smooth: 1.5–1.6 calls/h). The average number of bats observed also did not differ significantly (textured: 5–7 bats/h; smooth: 6–9 bats/h). A textured coating was applied to one turbine (around the entire turbine from 10–43 m above ground) in each of two pairs in June 2017. The other turbine in each pair was left smooth. Paired turbines (1 ha apart) had similar bat activity during previous surveys. Bats were surveyed on 27 nights at each turbine using night-vision, thermal imaging cameras and bat detectors in June–September 2017.Study and other actions tested