From dusk till dawn: Ecoacoustic monitoring reveals wind energy impacts on roding Eurasian woodcock (Scolopax rusticola)

Renewable energy is vital for reducing carbon emissions, yet its infrastructure poses challenges for biodiversity. While wind power impacts on bats and raptors are well-studied, effects on elusive species remain largely unknown. The Eurasian Woodcock (Scolopax rusticola), a nocturnal forest bird, performs characteristic courtship flights at twilight known as roding. Despite evidence suggesting potential impacts on the species, details regarding the effects of wind energy use in forests on the habitat use and roding of Woodcocks remain unclear. We compared the vocal activity of Woodcocks at 15 windfarms scattered throughout central Germany. We used passive acoustic monitoring in a paired design, with control sites situated ≥3 km from wind turbines. We took recordings for three hours at dawn and dusk over ten days in June 2023—during peak roding season. We validated presumed Woodcock matches by BirdNET to assess precision for the species, accompanied by a stratified screening to estimate recall rates. We compared true vs. false positive BirdNET hits in relation to the twilight periods during dawn and dusk, respectively. Further, we compared the presence of Woodcocks as well as their continuity throughout the recording period, separately for dusk and dawn. We found that the Woodcocks’ roding activity was confined by darkness and by the vocal activity of other species (mainly Thrushes), which during the morning/evening chorus partially overlapped with the acoustic niche of the Woodcocks. Detection probabilities of BirdNET were not affected by differences in soundscapes with and without windfarm instalments. Likewise, species’ presence did not change between windfarm and control sites. However, we found that roding activity of Woodcocks was significantly reduced at wind power sites by around 59% (95%CI = 40%-75%). We discuss our findings with regards to environmental management of the species for windpower planning, including the use of passive acoustic monitoring for elusive species.