Among the most handsome of all ducks, the northern pintail (Anas acuta) is recognized by its slender build, long, elegant neck and elongated, spiky central tail feathers, a feature that gives rise to its common name. A graceful waterbird with long, narrow wings, during the breeding season the male northern pintail has a chocolate-brown head, white underparts and a white neck, with a thin, white line extending up the back of the neck, and a long, black tail bordered by yellowish-tan patches. The upper back and sides are grey, the lower back feathers are black with pale edges, and the rear of the wing is bronzy-greenish, with a black band and white rear edge. The eyes are dark brown and the legs are grey. At other times of the year, the male northern pintail has duller, brownish plumage, with fine, dark streaks on the neck and broad, dark barring on the upperparts. The female northern pintail lacks the colorful plumage of the male, with largely brown upperparts, a tan crown and face, whitish underparts, and a bronzy-greenish band on the rear of the wing, as well as bluish-grey legs and a dull black bill.

Walking or running with a slight waddle, the northern pintail is actually quite agile on land, but is most graceful and acrobatic in flight. It is able to achieve great speeds while flying, earning the species the nickname ‘greyhound of the air’. The northern pintail is a rather quiet bird, but the male may emit a mellow, whistled “kwee” or “kwee-hee”, while the female produces a hoarse, muffled “quack”.