Résumé
The rapid expansion of wind power energy has direct negative impacts on
biodiversity, notably on avifauna through collisions with turbines. A
better understanding of the collision causes is the key to improving
mitigation efforts. Collisions are the result of a combination of
environmental factors that increase bird sensitivity and exposure to
collisions. To date, potential risk factors have mostly been assessed
individually, in few species of interest and/or at a small spatio-temporal
scales, despite the multifaceted nature of collision risk. To fill this
gap, we used for the first time data from automatic detection systems
(optic systems that automatically detect and monitor birds in the vicinity
of wind turbines) to simultaneously assess the effects of behavioral and
environmental factors on bird sensitivity (here, estimated as the bird
presence in the risk zone) and exposure (here, estimated as the frequency
with which birds use the zone). We analyzed 205,867 bird trajectories from
11 wind energy facilities in France, recorded between 2018 and 2023. We
obtained results similar to previous studies relying on other methods
(i.e., GPS, direct observations). Results suggest that bird sensitivity
was higher during periods of high bird activity (first hours of daylight,
migrations). They also suggest that sensitivity and exposure may increase
in conditions that reduced the birds’ visual perception of turbines (high
nebulosity, low visibility, low rotor speeds) and in conditions that may
influence the flight height of birds (high temperatures, high wind
speeds). We found a nonsynchronicity of exposure and sensitivity peaks,
highlighting the importance of considering both drivers of risk when
investigating the collision risk. However, our results show a high
variability between species, flight behaviors, and sites that should be
addressed in the future to clarify the relationships between collision
risk, birds’ visual perception of the turbine, and behavior. Data from
automatic detection systems can be a promising non-invasive approach that
requires few human and logistic resources to better understand bird
behavior in anthropogenic environments and collision causes. These new
insights are valuable to biodiversity stakeholders in bridging the gap
between the productivity of wind energy facilities and biodiversity
conservation.