Heward C.J., MacColl A.D.C., Lowe A., Ward A. & Hoodless A.N. (2025) Estimating Eurasian Woodcock roding range size using GPS-tracking. ARDEA 113 (2): 12-12

Eurasian Woodcock Scolopax rusticola perform a distinctive courtship display known as ‘roding’, in which male Woodcock travel over large areas of woodland and other suitable breeding habitats in search of females. Observations of roding provide the only practical basis for breeding season surveys of Woodcock, although our existing understanding of roding is derived from a very small number of studies. To provide more representative assessments of roding range size, i.e. the geographic area covered by a displaying male Woodcock, this study analysed fine-scale GPS data collected by tracking Woodcock during their courtship flights. Different methods for estimating roding range size are compared: minimum convex polygons, localised convex hulls and Brownian bridge kernels. Mean estimates of daily roding range size, produced using data from 16 tagged individuals, varied from 0.41–2.00 km2 depending on the method used, with the two most congruous methods suggesting averages of 1.11 km2 or 1.29 km2. The results presented here generally support the existing interpretation of roding as a lek-like system in which mating is determined by male-male competition and female mate selection. Roding ranges were somewhat larger than those provided by previous assessments and we recorded some individuals that made roding movements on a scale far exceeding any previous estimates. The results appear to lend cautious support to existing interpretations of roding count data but raise questions about how woodland size and connectivity may influence display behaviour and thus survey results.