Ultrasonic Deterrents To Reduce Bat Mortality at Wind Turbines—Short Science Summary

Bats

In North America, several bat species commonly collide with operating turbines. Although the ultimate cause of collisions is unknown, studies suggest bats may be attracted to turbines because they often approach turbine structures and spend extended periods of time (seconds to minutes) near them. To reduce bat mortality at wind farms, operators seek to reduce the amount of time bats spend near spinning turbine blades (known as exposure). Current approaches to reduce exposure include both curtailment, in which turbine operators stop turbine rotors from spinning during periods when bats are expected to be at the highest risk of collision, and deterrent technologies that seek to discourage bats from entering the rotor-swept area or at least limit the amount of time spent there.

The use of ultrasonic deterrent devices that emit one or more high-frequency sounds has been the most tested technique. The idea behind using ultrasound as a deterrent is it disrupts the ability of bats to effectively echolocate (sometimes referred to as signal jamming). According to this idea, introducing ultrasonic noise in the environment in the same frequency ranges that bats use to echolocate makes it difficult for bats to reliably interpret their own ultrasonic vocalizations. Bats are expected to vacate environments where echolocation is required but becomes unreliable. To test this hypothesis, researchers have investigated the behavioral responses of bats in laboratory (Spanjer 2006) and natural settings (Szewczak and Arnett 2007; Gilmour et al. 2020; Fritts et al. 2024).

In one of the earliest studies on the topic, Szewczak and Arnett (2007) used ultrasonic deterrents at a natural pond that bats frequented for drinking and foraging. Szewczak and Arnett demonstrated that ultrasonic deterrents greatly reduced the overall bat activity rates within a distance of approximately 20 meters (m). Despite relatively consistent results using ultrasound deterrents in natural settings (Szewczak and Arnett 2007; Gilmour et al. 2020) and as a tool to discourage bats (at least temporarily) from approaching buildings and bridges (Zeale et al. 2016; Aldemir Bektas et al. 2022), researchers’ ability to reduce bat mortality rates around wind turbines has been inconsistent (Table 1). For example, Weaver et al. (2020) found that ultrasonic deterrents reduced hoary bat (Lasiurus cinereus) and Brazilian free-tailed bat (Tadarida brasiliensis) fatalities but found no difference in the number of northern yellow bat (Lasiurus intermedius) carcasses between turbines with and without ultrasonic deterrents. Despite overall reductions in bat fatalities, several studies reported increased fatalities when considering species-specific effects.

The table below contains the literature relevant to this summary document and will continue to be updated as new literature is added to Tethys.

Title Author Date Content Type Technology Stressor Receptor
Estimating habitat loss due to wind turbine avoidance by bats: Implications for European siting guidance Barre, K., Le Viol, I., Bas, Y., Julliard, R., Kerbiriou, C. Journal Article Wind Energy, Land-Based Wind Attraction, Avoidance, Collision, Displacement, Habitat Change Bats
Using network analysis to identify indicator species and reduce collision fatalities at wind farms Sebastian-Gonzalez, E., Perez-Garcia, J., Carrete, M., Donazar, J., Sanchez-Zapata, J. Journal Article Wind Energy, Land-Based Wind Collision Birds, Bats
Texturizing Wind Turbine Towers to Reduce Bat Mortality Bennett, V., Hendrix, T. Report Wind Energy, Land-Based Wind Avoidance, Collision Bats
Estimating the Likelihood of Bat Barotrauma using Computational Simulations and Analytical Calculations Lawson, M., Jenne, D., Thresher, R. Conference Paper Wind Energy, Land-Based Wind Collision Bats
Ultrasonic Bat Deterrent Technology Kinzie, K. Report Wind Energy, Land-Based Wind Collision Bats
A review of searcher efficiency and carcass persistence in infrastructure-driven mortality assessment studies Barrientos, R., Martins, R., Ascensão, F., D'Amico, M., Moreira, F., Borda-de-Água, L. Journal Article Wind Energy, Land-Based Wind Collision Bats, Birds, Human Dimensions
Field validation of radar systems for monitoring bird migration Nilsson, C., Dokter, A., Schmid, B., Scacco, M., Verlinden, L., Backman, J., Haase, G., Dell'Omo, G., Chapman, J., Leijnse, H., Liechti, F. Journal Article Wind Energy, Land-Based Wind, Fixed Offshore Wind, Floating Offshore Wind Collision, Displacement Bats, Birds
Inconspicuous echolocation in hoary bats (Lasiurus cinereus) Corcoran, A., Weller, T. Journal Article Wind Energy, Land-Based Wind Collision Bats
Mitigating the negative impacts of tall wind turbines on bats: Vertical activity profiles and relationships to wind speed Wellig, S., Nussle, S., Miltner, D., Kohle, O., Glaizot, O., Braunisch, V., Obrist, M., Arlettaz, R. Journal Article Wind Energy, Land-Based Wind Collision Bats
Tier 4 Post-Construction Mortality Monitoring Study for the Odell Wind Energy Project Cottonwood and Jackson Counties, Minnesota: Final Fatality Report December 2016 – December 2017 Chodachek, K., Gustafson, Z. Report Wind Energy, Land-Based Wind Collision Bats, Birds
Impacts of onshore wind energy production on birds and bats: recommendations for future life cycle impact assessment developments Laranjeiro, T., May, R., Verones, F. Journal Article Wind Energy, Land-Based Wind Attraction, Avoidance, Collision, Displacement, Habitat Change Bats, Birds
New Creek Wind Project 2017 Post-construction Monitoring Stantec Consulting Report Wind Energy, Land-Based Wind Collision Bats, Birds
When the Excrement Hits the Fan: Fecal Surveys Reveal Species-Specific Bat Activity at Wind Turbines Bennett, V., Hale, A., Williams, D. Journal Article Wind Energy, Land-Based Wind Attraction, Collision Bats
Bat flight height monitored from wind masts predicts mortality risk at wind farms Roemer, C., Disca, T., Coulon, A., Bas, Y. Journal Article Wind Energy, Land-Based Wind Collision, Attraction Bats
Turbine Induced Bird and Bat Fatalities at Wind Projects: Statistical Methods for Mortality Estimation Using Road and Pad Carcass Surveys Maurer, J. Thesis Wind Energy, Land-Based Wind Collision Birds, Bats
Performance test and verification of an off-the-shelf automated avian radar tracking system May, R., Steinheim, Y., Kvaløy, P., Vang, R., Hanssen, F. Journal Article Wind Energy, Land-Based Wind, Fixed Offshore Wind, Floating Offshore Wind Collision Bats, Birds
Bat fatalities at wind farms in Taiwan Chou, C., Hsieh, T., Liu, W., Chou, T., Huang, Y., Rydell, J. Journal Article Wind Energy, Land-Based Wind Collision Bats
Wildlife and Wind Farms - Conflicts and Solutions, Volume 1. Onshore: Potential Effects Perrow, M. Book Wind Energy, Land-Based Wind Collision, Displacement, Habitat Change, Noise Bats, Birds, Ecosystem Processes, Physical Environment, Invertebrates, Reptiles, Terrestrial Mammals
Wildlife and Wind Farms - Conflicts and Solutions, Volume 2. Onshore: Monitoring and Mitigation Perrow, M. Book Wind Energy, Land-Based Wind Collision Bats, Birds
Impact of wind turbines on bat activity: an ommited long-distance concern Barre, K., Julliard, R., Le Viol, I., Bas, Y., Kerbiriou, C. Presentation Wind Energy, Land-Based Wind Avoidance, Collision Bats
A Spatial Explicit Agent Based Model Approach to Evaluate the Performance of Different Monitoring Options for Mortality Estimates in the Scope of Onshore Windfarm Impact Assessments Santos, M., Bastos, R., Ferreira, D., Santos, A., Barros, P., Travassos, P., Carvalho, D., Gomes, C., Vale-Gonçalves, H., Braz, L., Morinha, F., Paiva-Cardoso, M., Hughes, S., Cabral, J. Journal Article Wind Energy, Land-Based Wind Collision Birds, Bats
Bat Mortality Due to Wind Turbines in Canada Zimmerling, J., Francis, C. Journal Article Wind Energy, Land-Based Wind Collision Bats
Understanding the Risk of European Protected Species (Bats) at Onshore Wind Turbine Sites to Inform Risk Management Mathews, F., Richardson, S., Lintott, P., Hosken, D. Report Wind Energy, Land-Based Wind Collision Bats
Bats in a tropical wind farm: species composition and importance of the spatial attributes of vegetation cover on bat fatalities Bolivar-Cime, B., Bolivar-Cime, A., Cabrera-Cruz, S., Munoz-Jimenez, O., Villegas-Patraca, R. Journal Article Wind Energy, Land-Based Wind Collision Bats
Post-Construction Avian and Bat Mortality Monitoring at the Alta X Wind Energy Project, Kern County, California. Final Report for the Second Year of Operation: April 2015 – April 2016 Thompson, J., Boyd, C., Lombardi, J. Report Wind Energy, Land-Based Wind Collision Bats, Birds
Multiple Mortality Events in Bats: A Global Review O'Shea, T., Cryan, P., Hayman, D., Plowright, R., Streicker, D. Journal Article Wind Energy, Land-Based Wind Collision Bats
The Impacts of Small and Medium Wind Turbines on Bats Moyle, A. Thesis Wind Energy, Land-Based Wind Habitat Change, Displacement, Collision, Avoidance, Attraction Bats
Scavenging of small bird carrion in southwestern Germany by beetles, birds and mammals Henrich, M., Tietze, D., Wink, M. Journal Article Wind Energy, Land-Based Wind Collision Bats, Birds
Guidelines for Conducting Bird and Bat Studies at Commercial Wind Energy Projects New York State Department of Environmental Conservation Report Wind Energy, Land-Based Wind Collision, Habitat Change Bats, Birds
The habitat association of bats in the South Okanagan Valley, British Columbia, Canada: Radar-acoustic surveys to assess the use of vineyards by insectivorous bats (Vespertilionidae) Dagenais, M. Thesis Wind Energy, Land-Based Wind Collision Bats
Reducing the Collision Risk for Bats at Onshore Wind Turbines (RENEBAT II) Behr, O., Brinkmann, R., Korner-Nievergelt, F., Nagy, M., Niermann, I., Reich, M., Simon, R. Report Wind Energy, Land-Based Wind Collision Bats
Impact of Wind Energy on Bats: A Summary of Our Current Knowledge Hein, C., Schirmacher, M. Journal Article Wind Energy, Land-Based Wind Attraction, Collision Bats
Framework for Testing the Effectiveness of Bat and Eagle Impact-Reduction Strategies at Wind Energy Projects Sinclair, K., DeGeorge, E. Report Wind Energy, Land-Based Wind Collision, Avoidance, Attraction Raptors, Birds, Bats
Wind Energy Development: Methods for Assessing Risks to Birds and Bats Pre-Construction Katzner, T., Bennett, V., Miller, T., Duerr, A., Braham, M., Hale, A. Journal Article Wind Energy, Land-Based Wind Collision, Habitat Change Bats, Birds
Assessing spring direct mortality to avifauna from wind energy facilities in the Dakotas Graff, B., Jenks, J., Stafford, J., Jensen, K., Grovenburg, T. Journal Article Wind Energy, Land-Based Wind Collision Birds, Bats
Impacts to Birds and Bats Due to Collisions and Electrocutions from Some Tall Structures in the United States: Wires, Towers, Turbines, and Solar Arrays - State of the Art in Addressing the Problems Manville, A. Book Chapter Wind Energy, Land-Based Wind Habitat Change, Displacement, Collision, Avoidance, Attraction Birds, Bats
Problematic Wildlife: A Cross-Disciplinary Approach Angelici, F. Book Wind Energy, Land-Based Wind Habitat Change, Collision Birds, Bats
2015 Bird and Bat Post Construction Monitoring Report – Laurel Mountain Wind Energy Project Stantec Consulting Report Wind Energy, Land-Based Wind Collision Bats, Birds
Using DNA barcoding to improve bat carcass identification at wind farms in the United States Korstian, J., Hale, A., Bennett, V., Williams, D. Journal Article Wind Energy, Land-Based Wind Collision Bats
Impact of wind facilities on bats in the Neotropics Rodríguez-Durán, A., Feliciano-Robles, W. Journal Article Wind Energy, Land-Based Wind Collision, Attraction Bats
Displaying 121 - 160 of 348 results