Sanderling (Calidris alba)

Sanderlings are great flyers. Their migration takes them over 12, 000 km, from the Arctic to the southern itp of South America!

Description

The sanderling is a small sandpiper, as its name suggests- it measures only 18-20 cm from head to tail. It undergoes a dramatic change in appearance when the breeding season approaches, its upper parts darkening from unmarked, pale grey to mottled and streaked rusty chestnut and blackish brown. Its underparts are plain white in winter, but in summer parts of its breast are rusty, with darker streaks. Its call is a distinctive, short and sharp “twick!” or “kwit!”

Distribution

Sanderlings breed in the Arctic Isalnds, reaching north to the tip of Ellesmere Island, and in a few isolated locations on the mainland along the Arctic coast. They are, however, absent from Baffin Island and from a few small islands to the west of Ellesmere Island. This species is a long-distance migrant, wintering as far south as Tierra del Fuego, Argentina. Much of the mortality of first year sanderlings occurs during the long journey from the Arctic to South America.

Ecology

Sanderling nests are shallow depressions located in the vicinity of a freshwater pond or lake.

This species eats mostly insects and spiders, but also feeds on a small amount of vegetation in the spring. The sanderling feeds like many other shorebirds, by probing its bill into wet sand or mud, and by picking food items off the ground. Unlike other sandpipers, however, it probes with its bill partly open, rather than shut.

While migrating, sanderlings often feed in small, tight, groups within larger, mixed-species flocks. These birds may select feeding territories, areas of shore where they feed, which they defend against other birds. Although feeding territories are more stable on wintering grounds, they occasionally occur on a temporary basis at migratory staging points, with territory size increasing where prey are more scarce. When approached closely, sanderlings will more often run away than fly.