This species is very similar in pattern to Lesser Yellowlegs, but is larger, with a longer bill, proportionally shorter legs, and a different call. Wingtips extend just beyond the tail. The bill is black (with a variable amount of dull olive at the base), slightly upturned. Bill length is approximately 150% the front to back length of the head. Alternate Adult: Upperparts and breast are mottled black, dull brown, and white. The belly and vent are white with extensive dark barring on the sides. Basic Adult: More uniform gray to brownish-gray upperparts and breast, with small paler gray to near white spotting on the feather margins. Juvenile: Similar to basic adult, but upperparts darker overall and with bold white spotting on feather margins and more defined streaking on the breast. In flight: White rump and base of tail are obvious. Toes extend beyond the tail. Adult Greater Yellowlegs molt their flight feathers in August and September, so birds with missing primaries are common during southbound migration.

Length: 29 (cm) Wingspan: 58 (cm)

Voice:

Call is a loud descending series of three or more notes: Klee klee klee. Song is a rolling whee-oodle whee-oodle.

Habitat:

Breeds in open woodland, bogs, muskeg. During migration and winter, uses mudlats, flooded fields, ponds, wet meadows.

Behavior:

Very vocal. Often rock backwards when feeding or standing. Holds wing out for a moment after landing. Tends to move about in a more jerky or lurching fashion than Lesser Yellowlegs.

Feeding:

Wades along water's edge or into belly-deep shallows to hunt for invertebrates, small fish, occasionally frogs. Sometimes swims in small flocks to herd fish.