The dunlin (Calidris alpina) is a small, round shouldered shorebird with a slim, longish, slightly downcurved bill. In summer it has rich chestnut and black on crown and back; pale, dark-streaked breast and a large, conspicuous black patch on underside during breeding season. In winter, grey-brown above; grey-streaked breast; white belly. Narrow white wingbar and white underwing in all feathers. The bill is long, black, and droops downward at the tip The Dunlin is a very abundant shorebird throughout the Northern Hemisphere. In the winter, it often gathers on the coasts of North America, Europe, and Asia in vast flocks of tens of thousands. The dunlin can be seen along most of the Atlantic coast during the winter, and they breed in the far north of Canada near the Arctic circle.