About Calidris alba (Pallas, 1764)
The sanderling, scientifically named Calidris alba (Pallas, 1764), is a small, plump species of sandpiper. It measures 18–20 cm (7–8 in) in length, and weighs between 40–100 g (1+1⁄2–3+1⁄2 oz). In winter plumage, the sanderling is very pale, appearing almost white aside from a dark shoulder patch; this characteristic gives the species its specific name alba, which means "white" in Latin. By summer, its face and throat turn brick-red. Juvenile sanderlings have a black-and-white spangled pattern that is far more contrasting than the plumage of adult birds. If their size is misjudged, breeding-plumage sanderlings can be mistaken for some varieties of stint, while winter-plumage sanderlings can be confused with dunlins or red knots. When seen clearly, sanderlings can be distinguished from other small wading birds by their lack of a hind toe, and they also have distinctive behaviour. Sanderlings breed in High Arctic regions across North America, Europe, and Asia. In North America, they breed in the Canadian Arctic Archipelago, Nunavut, and Greenland, with smaller breeding populations present in Alaska. In Eurasia, their breeding range includes Spitsbergen and northern Russian areas stretching from the Taymyr Peninsula to the New Siberian Islands. During the northern winter, sanderlings have an almost cosmopolitan distribution along the world's marine coasts. The species is a complete long-distance migrant, traveling between 3,000 to 10,000 km (2,000 to 6,000 mi) between its breeding grounds and wintering sites. Individuals that travel longer distances arrive later at their destinations and leave sooner. Most adult sanderlings leave the breeding grounds in July and early August, while juvenile birds leave in late August and early September. Northward migration back to breeding grounds begins in March from the southern end of the species' winter distribution. The sanderling's breeding habitat is coastal tundra located north of the 5 °C (41 °F) July isotherm. The species typically nests on dry stony areas near wet landscapes, at elevations ranging from 60 m (200 ft) to 800 m (2,600 ft) above sea level. During winter and migration, sanderlings are most often found on coastal sandy beaches, but they also occur on tidal sand flats, mud flats, and the shores of lakes and rivers. They only appear on rocky shores infrequently.
