The need to reduce bird collisions with wind turbines has prompted numerous studies and research efforts. However, this issue is still most often addressed by simply “counting carcasses,” which does not allow for a clear understanding of the conditions in which these collisions occur.
At Biodiv-Wind, we have always believed that we can only provide meaningful solutions to this problem by first understanding the events themselves. But to do that, we need to see them.
This is why, for the past 10 years, we have been offering wind energy operators tools not only to detect birds approaching wind turbines, but also to detect collisions by continuously monitoring intrusions into the rotor area.
Thanks to this approach—and although collision footage is not easy to watch—we have been able to document several dozen collision events involving a wide variety of diurnal bird species.
In this report, we share our findings on the correlation between rotor speed and the number of bird collisions, focusing on three raptor species: the Red Kite, the Common Kestrel, and the Griffon Vulture.
Our results show that slowing down the rotors does indeed reduce the risk of collisions. But they also document, for the first time, that collisions can still occur even when the rotors are fully stopped or nearly stationary.
Finally, we demonstrate that for the Common Kestrel and the Griffon Vulture, certain rotation speeds are significantly more hazardous, while the patterns for the Red Kite are less clear.
This study also shows that a complete stop of the turbines is not always necessary to significantly reduce collision risk—opening the door to a more refined turbine management strategy that balances species protection with energy production.
Additional studies are currently underway to include other species and to explore further factors that may explain collision events, such as behavior or local environmental conditions.
Enjoy the read!
