Sanderling  |  

An active, pale wader reaching 20 cm long, with a wingspan of approximately 40 cm and a weight of approximately 50–60 g. Females are slightly larger than males. The non-breeding adult is pale grey above and white below, with a black patch at the angle of the wing. It has a short, straight, broad-based black bill, blackish-brown wings with broad, white wing-stripes, and short, black legs that only have three toes (no hind toe as in other sandpipers). In flight, it shows the widest white wing-bar of any sandpiper, on a very dark wing. The forehead and eyebrows are white; iris is dark brown. The rump and tail have a brown centre and white sides. Elements of the rufous breeding plumage may be visible in some birds just after their spring arrival or before their autumn departure, and in some overwintering birds. When breeding, which occurs in the Northern Hemisphere, the Sanderling’s plumage changes with a brick-red and grey-black pattern dominating the head, neck, back and wings of the bird. Juveniles have similar plumage to non-breeding adults, though more pronounced streaking occurs on the crown and a buff fringing may be seen on wing coverts. The underparts and other areas of white can have a buff wash or creamy appearance. This species is gregarious, being typically found in small to large flocks. At favoured localities birds can be in the hundreds. They associate with other waders and may join mixed roosts, but often roost high on the beach in a tight monospecific flock. They tend to migrate in flocks of less than a thousand. The species is noted for the fact that it can build up fat reserves to 60% of its body weight, which assists the birds in the few long-distance flights they make between breeding and non-breeding foraging grounds.