A new study commissioned by the German Offshore Wind Energy Association (BWO) has found that migratory birds consistently avoid wind turbines, with a collision rate far lower than previously assumed. The research, conducted in a near-shore wind farm in northern Germany, provides one of the most comprehensive datasets to date on how birds behave around wind installations — and offers a solid scientific foundation for the continued, environmentally responsible expansion of offshore wind energy.

Filling knowledge gaps on bird behavior

Millions of migratory birds cross the North and Baltic Seas each year, traveling through areas where offshore wind farms operate. Until now, scientific understanding of potential risks to these birds has been limited. To address this gap, BWO and several leading energy companies commissioned a study using advanced monitoring technologies to evaluate the actual collision risk at an onshore wind farm located close to the coast.

The goal was clear: use precise, real-time behavioral data to verify long-held assumptions about bird movements and turbine interactions.

Over 99.8% of migratory birds steer clear of turbines

Over the course of 18 months, researchers recorded more than four million individual bird movements. The results challenge earlier expectations linking higher migration intensity with increased collision risk, casting doubt on the effectiveness of blanket turbine shutdowns during peak migration periods.

Key findings include:

• Extremely high avoidance rates: More than 99.8% of both daytime and nighttime migratory birds avoided the turbines altogether — significantly higher than previous estimates.

• No link between migration density and collisions: Even during peak nocturnal migration, very few birds entered rotor zones, contradicting the assumption that more birds automatically lead to more collisions.

• Breakthrough in research methods: The study combined radar and AI-driven stereo camera systems to deliver unprecedented accuracy in detecting bird flight paths within turbine rotor planes. These technologies enabled reliable calculations of avoidance behavior and collision frequency.

“The new study shows that migratory birds avoid wind turbines. This confirms that the environmentally sound expansion of offshore wind energy works in harmony with these birds and not against them,” said Stefan Thimm, Managing Director of BWO. “With this research, we want to depoliticize the discussion, improve the data basis, and make decisions based on facts.”

Dr. Jörg Welcker, Head of Research and Development at BioConsult SH GmbH & Co. KG, highlighted the importance of the study’s innovative methods.

“We used state-of-the-art tools. AI-controlled stereo cameras measured activity in the rotor area, and specialized bird radar tracked migration patterns. By comparing both datasets, we obtained precise avoidance rates,” Welcker explained. “We also searched for potential collision victims, resulting in a comprehensive picture of the actual collision risk.”

The study was commissioned by the German Offshore Wind Energy Association and financed by several major industry players, including DanTysk Sandbank, EnBW AG, Iberdrola, Ørsted, RWE, Skyborn Renewables, Vattenfall, and WindMW GmbH. BioConsult SH conducted the research.

As offshore wind expansion accelerates across Europe, the findings offer policymakers, developers, and environmental groups valuable reassurance: with proper monitoring and technological advancement, large-scale renewable energy growth can coexist safely with migratory bird populations.