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.