Do wind turbines kill birds? Safeguarding climate and nature

Bird death by wind turbine occurs mostly due to collisions with spinning turbine blades. The blades are often hard to see, particularly in poor light or fog. Birds also collide with the high-voltage power lines that travel to and from wind farms.

Estimates vary – from hundreds of thousands in the US to millions worldwide. The rapid construction of large-scale wind farms could cause these numbers to sharply increase in the future.

Species most at risk include large raptors such as eagles, hawks and vultures that fly at blade height, as well as migratory songbirds and seabirds on coastal routes. Birds of prey are particularly vulnerable because they soar slowly and may not avoid blades in time.

The risk of bird collisions is influenced by factors including the location of the wind farm, the types of birds in the area, and the design and spacing of the turbines themselves. Wind farms located along major bird migration routes or near important habitats like wetlands, nesting sites or feeding areas are more likely to experience collisions.

Several mitigation measures are being implemented to minimise bird deaths caused by wind turbines. These include altering turbine design, strategic placement and operational adjustments.

Studies in Norway and the UK show painting one blade black can reduce bird collisions by around 70 per cent.

Environmental assessments now steer turbines away from known bird migration routes and eagle territories. Developers in migration hotspots must balance site choice with ecological risk.

Some farms temporarily halt turbines during migration periods or when large birds are detected nearby. Although effective, this involves production compromises and legal compliance.

Radar, acoustics and thermal cameras can be used to detect bird movement, but manual surveys are limited and subject to weather and human error. The Norwegian startup Spoor uses AI technology to monitor bird activity at wind farms. Using computer vision, the solution automates remote detection of birds in flight and identification of bird species.

Spoor helps to inform turbine siting and operational shutdowns. This supports the development of bird-safe wind turbine systems and makes biodiversity monitoring cost-effective. 

“Bird monitoring is essential for the entire wind farm life cycle,” explains Ask Helseth, CEO and co-founder of Spoor AS. “In the pre-construction phase, our data and analysis support design decisions to ensure the wind farm is built with the least disruption to bird activity. In the latter phase, we help to mitigate the impact of current operations and plan for more eco-friendly wind farms in the future.”

Wind power is helpful to achieving net zero goals. Renewable energy prevents far more bird deaths and habitat loss by reducing fossil fuel usage, which is one of the biggest threats to biodiversity. However, even modest per turbine mortality adds up when millions of turbines are installed. Local wildlife populations depend on careful siting and active measures. Efforts like painting blades and Spoor’s AI monitoring support the development of bird-safe wind turbine systems. With better planning and technology, turbines and wildlife can coexist more harmoniously.