New audio deterrents reduce raptor collisions with wind turbines
A new study demonstrates that emitting warning sounds from wind turbines can effectively deter large soaring raptors, like eagles, from entering the rotor-swept zone and reduce collisions.
Wind farms, while crucial for reducing carbon footprints, pose a significant risk to large soaring birds such as eagles, hawks, and vultures. These birds often have limited ability to detect approaching turbine blades, leading to fatal collisions, particularly in windy conditions where both bird and turbine activity are high. This issue is especially relevant in western North America, where some wind farms are situated near populations of protected species like bald and golden eagles.
A collaborative research effort involving H.T. Harvey & Associates (now Integral Consulting Inc.) and the Renewable Energy Wildlife Institute has evaluated a new deterrent system. The study, published in the Journal of Raptor Research, focused on the effectiveness of DTBird audio deterrents installed at two commercial wind farms in the western U.S.: the Manzana Wind Power Project in California and the Goodnoe Hills Wind Farm in Washington.
The DTBird system emits specific sounds when a large raptor is detected approaching a turbine. Initially, a "whistle-whoop" signal is broadcast to capture the bird's attention. If the bird continues its approach, a louder "dissuasion signal" is activated to discourage it from entering the danger zone, known as the rotor-swept zone (RSZ).
Analysis of video footage revealed that the deterrents successfully dissuaded approaching raptors, including golden eagles, bald eagles, turkey vultures, and various hawk species, more than 50% of the time across both study sites. The study noted that larger species, such as eagles, showed increased responsiveness in stronger winds, potentially due to the combination of faster turbine rotation and the audio cues making the turbines more noticeable.
Interestingly, the research also found that birds already on a safe trajectory around turbines were less likely to respond to the deterrents. Conversely, birds at the highest risk of collision did not always exhibit the most effective avoidance, possibly due to insufficient time to react. This first-of-its-kind study in North America provides valuable, evidence-based data for wildlife conservation policy and the ongoing development of renewable energy infrastructure.
This development marks a significant step in mitigating the ecological impact of wind energy. By employing acoustic deterrents, the technology addresses the sensory limitations of large raptors, offering a non-invasive method to reduce avian mortality. This research provides crucial data for regulatory bodies and wind farm operators, contributing to the broader goal of sustainable energy development that coexists with wildlife conservation efforts.
Edited by the news editor with AI from the original report — please refer to the original source.