The Dunlin (Calidris alpina) is a species of wading bird found in the Arctic and sub-Arctic regions of northern Europe, Asia, Alaska, and northern Canada. Europe and Asia populations migrate south to Africa and southeast Asia. Alaskan and Canadian birds migrate to the Pacific and Atlantic coasts of North America. Some northern Alaskan nesting colonies migrate into Asia. It is a highly gregarious bird in the winter and will sometimes form large flocks on coastal mudflats or sandy beaches. Large numbers can often be seen around stop-overs during migration. It is one of the most common waders throughout its range.
The adult is 6.75 to 8.25 inches long with a 12.5 to 14.25 inch wingspan. It is a stout bird with a thick bill. The adult also shows a unique black belly which no other similar wader possesses. In winter it is basically gray above and white below. They usually have black marks on the flanks or belly and show a strong white wingbar in flight. The legs and slightly decurved bill are black. The female has a longer bill than the male. There are a number of subspecies that differ mainly in coloration in the breeding plumage and bill length. The young are brown above with two white “V” shapes on the back.
The Dunlin has a characteristic “sewing machine” feeding behavior. It moves along the coastal mudflat beaches carefully picking insects, mollusks, worms and crustaceans from the ground. Insects are the main source of food on the nesting grounds. The nest is a shallow scrape on the ground lined with vegetation. The female lays four eggs that are incubated by both male and female. The chicks are precocial (able to move about freely at birth). They start to fly at about three weeks of age. The adult male provides most of the care as the female usually leaves the breeding area once eggs are hatched. The call of the Dunlin is a typical sandpiper “peep”, and the song is a harsh trill.
The Dunlin is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.