Swainson's Hawk

Swainson's Hawk

Swainson's Hawk is a distinctive buteo of the North American Great Plains and western grasslands, known for its long, narrow, pointed wings suited to efficient soaring over vast open landscapes, and for undertaking one of the longest migrations of any raptor, traveling to the pampas of Argentina each winter.

Plumage is quite variable, ranging from light to dark morphs, but the contrast between dark flight feathers and paler underwing coverts is a useful and fairly consistent feature across the variation.

Identifying Swainson's Hawk Feathers

• Primaries/secondaries: dark brown to blackish, notably darker than the paler underwing covert feathers, creating a strong two-tone contrast on the underwing not seen in most other buteos.
• Tail feathers: brown with numerous narrow, faint bands and a slightly darker terminal band, less boldly marked than Red-shouldered or Broad-winged Hawk tails.
• Body feathers: light-morph birds show a dark brown breast 'bib' contrasting with pale unmarked belly feathers; dark-morph birds have largely uniform dark brown body feathers throughout.
• The dark flight feather vs. pale covert contrast on the underwing is the single most useful clue for separating this species' feathers from other North American buteos.

Plumage

Light-morph adults show a dark brown head and breast bib contrasting with a pale, often buffy belly, dark brown upperparts, and notably dark flight feathers against paler wing coverts. Dark-morph and intermediate individuals occur regularly, showing more uniformly dark brown body plumage while retaining the dark-flight-feather contrast. Juveniles are more heavily streaked below. Sexes look similar in plumage.

Habitat & Range

Breeds across open grassland, prairie, and agricultural regions of the western and central United States and Canada. One of the longest-distance migrant raptors, it travels in large flocks to winter on the grasslands of Argentina and neighboring South American countries.

Behavior & Field Notes

Swainson's Hawks often forage in flocks over agricultural fields, and are notable for supplementing their diet with insects, particularly during migration and on the wintering grounds. They nest in isolated trees or on structures across open prairie. Migration involves spectacular large flocks streaming south in autumn. A feather with strongly contrasting dark flight feathers against paler wing covert feathers, found in open prairie or farmland, points toward this species over other regional buteos.