Variation in spacing between redshanks in flocks with respect to proximity to the high-risk woodland adjacent to the saltmarsh relative to other flock members, plotted separately for edge (open circles, top line fit) and centre (dots, bottom line fit) position within flocks. Analysis is a GLMM with normal errors, flock as a random effect: position×proximity to wood, W=19.86, p<0.001, B=−0.5444±0.12, B=0 for interaction term with edge position; position, B=−0.57±0.05 s.e.; proximity to wood, B=0.77±0.10 s.e.; constant, B=1.82±0.09; d.f.=1, n=61 flock and 1152 individual redshank responses (mean flock size=18.89±11.82 s.d., range 2–54).