Acadia National Park

Description  ADULT SUMMER Has streaked brown head and neck, with reasonably clear demarcation from mostly white underparts; note the pale, but not very prominent supercilium. Upperparts are brownish overall, with many feathers dark at center and with buff or white margins. ADULT WINTER Has gray-brown head and upperparts and streaked gray-brown chest and breast showing clear demarcation from white throat and underparts; note the pale supercilium. JUVENILE Recalls summer adult, but upperparts are warmer brown, feather margins are cleanly defined, and pale margins to mantle feathers align to create a striking "V."

Dimensions  Length: 6" (15 cm)

Habitat  Common. Nests on tundra wetlands and open marshes in boreal forest. Winters on coasts and beside freshwater across southern U.S. southward to South America.

Observation Tips  Easy to find outside breeding season; commonest during fall migration.

Range  New England, Plains, Rocky Mountains, Northwest, Texas, Southeast, California, Southwest, Eastern Canada, Florida, Mid-Atlantic, Western Canada, Alaska, Great Lakes

Voice  Utters a thin kreet call.

Discussion  The world's smallest shorebird. Distinguished from Semipalmated and Western sandpipers at all times by its yellow (not dark) legs; collectively, these three birds are known as "peeps." Needlelike bill is dark at all times. All birds show faint white wing stripe and white sides to tail in flight. Sexes are similar.