Understanding wind energy impacts on bats and testing reduction strategies in South Texas

  • Published source details Weaver S.P. (2019) Understanding wind energy impacts on bats and testing reduction strategies in South Texas. PhD thesis. Texas State University.


This study is summarised as evidence for the following.

Action Category

Deter bats from turbines using ultrasound

Action Link
Bat Conservation
  1. Deter bats from turbines using ultrasound

    A replicated, randomized, controlled study in 2017–2018 at a wind energy facility in an area of dry shrubland in Texas, USA (Weaver 2019) found that using ultrasonic deterrents on turbines reduced the number of fatalities of hoary bats Lasiurus cinereus and Brazilian free-tailed bats Tadarida brasiliensis but not northern yellow bats Lasiurus intermedius. On average, fewer bat carcasses were found at turbines with active ultrasonic deterrents than at those with inactive deterrents for hoary bats (active: 0.006 carcasses/night; inactive: 0.029 carcasses/night) and Brazilian free-tailed bats (active: 0.119 carcasses/night; inactive: 0.261 carcasses/night). The difference was not significant for northern yellow bats (active: 0.016 carcasses/night; inactive: 0.020 carcasses/night). Ultrasonic deterrents (arrays of 5–6 speakers emitting continuous sounds at 20–50 kHz) were installed on the nacelles of 16 wind turbines. During each night in July–October 2017 and 2018, eight randomly selected turbines had ‘active’ ultrasonic deterrents (turned on), and eight control turbines had ‘inactive’ deterrents (turned off). Carcass searches were conducted daily along transects in circular plots (100-m radius) around each of the 16 turbines.

    (Summarised by: Anna Berthinussen)

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