Breeding ecology remains poorly understood in many elusive species because conventional field methods rarely produce samples large enough to detect broad-scale ecological patterns. Here, we show that open-source online photographs can help overcome this limitation. Using 657 photographs representing 500 nests, we quantified breeding habitat and nest-site characteristics of the Eurasian woodcock (Scolopax rusticola) across its Palaearctic breeding range. We scored forest type, surrounding vegetation, nest concealment, proximity to trees and plant-based Ecological Indicator Values for Europe (EIVE). Woodcocks showed clear preferences for broadleaved stands, especially those associated with birch (Betula spp.) and oak (Quercus spp.), while coniferous trees were used less than expected from regional availability. Nest sites were typically located in mesic, slightly acidic, semi-open woodland habitats. At finer spatial scales, nest placement was highly variable, ranging from open ground to dense cover although many nests were placed close to trees or dead wood. Nesting habitat also changed seasonally, with later nests more often concealed by vegetation and more frequently located in mixed or coniferous stands. Our results demonstrate that openly available images can reveal otherwise inaccessible patterns in breeding ecology and provide a scalable tool for studying secretive species across large geographic ranges.
Sládeček M., Douda J., Brynychová K., Nutilová L., & Šálek M. (2026): Nest-site selection and seasonal habitat shifts of the enigmatic Eurasian woodcock across its Palaearctic breeding range revealed by open-source data. Royal Society Open Science, 13(6).
Link: https://royalsocietypublishing.org/rsos/article/13/6/260559/481978