Plump, medium-sized shorebird with very long bill. Extremely similar to Short-billed Dowitcher, and often flocks with it. Best distinguished by voice: a sharp, high-pitched “keek!” note, sometimes given in a series, unlike lower-pitched “tu-tu-tu” call of Short-billed. At all ages, look for subtle structural differences: Long-billed averages more hunch-backed, slightly longer-billed, and slightly taller, especially noticeable when in a mixed flock. Breeding birds have solidly salmon-orange underparts and rather dark upperparts with narrow rufous edges and white tips. Also look for sparse barring on the sides contrasting with denser spotting on the neck. Nonbreeding plumage is brownish-gray overall with a paler belly; extremely similar to Short-billed but averaging slightly darker and less patterned, especially on the breast and sides. Juveniles are easiest to identify: generally duller than Short-billed; look for plain dark-centered tertials and scapulars with narrow edging, rarely with some blurry internal markings. Breeds on tundra in high Arctic, and can be found in a variety of wetland habitats in migration and winter. Usually in flocks, feeding actively like a sewing machine. Tends to favor shallow marshy pools; somewhat more likely in freshwater habitats than Short-billed, but much overlap.