A medium-sized wader (8-9 inches), the Pectoral Sandpiper is mottled gray-brown above and on the head with a white breast, yellow legs, and dull white eye-stripes. This species is most easily separated from other similar sandpipers by its streaky upper breast, which contrasts greatly with its pale white belly below. During the breeding season, the breasts of male Pectoral Sandpipers puff out, giving these birds a ruffled appearance. Winter plumage is similar to that of the summer months, but is darker and duller overall. Males and females are similarly colored, but males are larger. The Pectoral Sandpiper breeds in the high arctic of North America and Asia, being found from the Hudson Bay east along the coast into central Siberia. This species is a long-distance migrant, with almost all birds wintering in southern South America. On migration, Pectoral Sandpipers may be found across North America. Pectoral Sandpipers primarily breed on wet tundra. In winter, this species inhabits wet grasslands and marshes, almost always in fresh water. On migration, Pectoral Sandpipers may also be found in salt marshes near tall grasses. This species primarily eats insects and larvae, but may also take small snails, crustaceans, and fish. Due to its remote breeding habitat, most birdwatchers never see the Pectoral Sandpiper during the summer. Similarly, many North American birdwatchers never travel far enough south to see this species during the winter. Pectoral Sandpipers are most likely to be observed in North America on migration, where it may be observed along the shore probing the mud for food with its bill. This species is most active during the day.
Fairly common migrant, more numerous from July to November than from April to June. Spring birds are more rufescent above and less buffy on the breast than are autumn birds. Males and females are alike.