This species is recognized by its slender build, white outer tail feathers, and constant tail-bobbing. Several subspecies occur, creating a lot of variation. Alternate Adult: Birds that breed in the Rocky Mountains are pale gray above, with light edges on the wing feathers. The underparts, cheek, and supercilium are unmarked buffy orange. Arctic breeders have slightly darker upperparts and dark auriculars. The underparts and supercilium are pale buff, with heavy dark streaks across the breast and down the sides. Basic Adult: Rocky Mountain breeders are buffy gray-brown above with a buffy supercilium. The underparts are buffy with fine dark streaks across the breast. Arctic breeders are slightly darker above with indistinct streaking on the back and a white supercilium. The underparts are white, turning pale buff on the sides and flanks, with dark heavy streaks across the breast, slightly paler streaks down the sides. The legs are usually dark. The Asian race (A.r. japonicus) is a rare migrant in Western Alaska and along the West Coast. These birds are darker above with more streaking on the back and two white wing bars. The underparts are white with a thick black lateral throat stripe, and heavy black streaks across the breast and down the sides. The legs are pale pinkish.

Length: 15 (cm) Wingspan: 25 (cm)

Voice:

Song is a long series of cheedle notes, lasting up to 20 seconds. Call is a high pip-it or pit.

Habitat:

Breeds on Arctic and mountain tundra. Winters along coasts, open fields, shorelines.

Behavior:

Constantly bobs tail. Often found in flocks numbering into the hundreds. When flushed, the loose undulating flocks show no particular organization.

Feeding:

Feeds on insects and seeds, on or near the ground.