The breeding behaviour of the KnotCalidris canutus

Abstract

This paper presents descriptions of the behaviour of KnotCalidris canutusbreeding in high arctic Canada. Knot nested within territories which were of little importance as a food source. Males defended territories by singing from the ground, aerial chases, threat displays (horizontal point), fighting, and low flights in which the wings were held vertically over the back (V‐wing flights).Songflights performed by males seemed to serve a mate‐attraction function. The commonest heterosexual display was a tail‐up display, used mainly by males prior to clutch completion. Males also used a nest scrape display and a ground point display in advertising potential nest sites to females. Behaviour preceding copulation was variable but usually included tail‐up displays and the male pecking the back of the female.Anti‐predator behaviour when on the nest involved remaining still until a predator was very close, whereupon distraction displays were used. Both sexes incubated but only males cared for chicks. Caring for chicks involved leading chicks to favourable feeding areas, brooding and vigilance, distraction displays, and harrassment or physical attack of avian predators.The displays used by breeding Knot tend to be unlike those of most congenerics and suggest that the Knot is a rather peripheral member ofCalidris.