The Swainson’s Hawk is a medium-to-large Buteo with a slim body, long pointed wings, and a relatively small head. Adults typically exhibit two main morphs: light morphs have whitish underparts with a rufous chest band and dark flight feathers contrasting with pale wing linings, while dark morphs are uniformly dark brown. The tail is grayish with narrow dark bands. Juveniles are paler below, with streaked breasts and more mottled wings. Body length ranges from 43–56 cm, wingspan 117–137 cm, and mass 0.8–1.4 kg. Adapted for long-distance soaring, it has long primary feathers and a buoyant flight style. Sexual dimorphism is minimal, with females slightly larger than males [1][2][3].
Yes — females slightly larger and heavier; plumage differences minimal.
43–56 cm length
0.8–1.4 kg
12–16 years in wild
Data deficient
Data deficient
~2 years
Apr–Jul (breeding in N America; non-breeding in Costa Rica)
Clutch of 1–4 eggs; one brood/year
The Swainson’s Hawk is a medium-to-large Buteo with a slim body, long pointed wings, and a relatively small head. Adults typically exhibit two main morphs: light morphs have whitish underparts with a rufous chest band and dark flight feathers contrasting with pale wing linings, while dark morphs are uniformly dark brown. The tail is grayish with narrow dark bands. Juveniles are paler below, with streaked breasts and more mottled wings. Body length ranges from 43–56 cm, wingspan 117–137 cm, and mass 0.8–1.4 kg. Adapted for long-distance soaring, it has long primary feathers and a buoyant flight style. Sexual dimorphism is minimal, with females slightly larger than males [1][2][3].
Open habitats such as grasslands, savannas, agricultural lands, and open woodlands during migration and wintering. In Costa Rica, observed in lowland pastures, fields, and open dry forest edges.
Opportunistic predator and insectivore; feeds on large insects (especially during non-breeding season), small mammals, reptiles, and occasional birds.
Diurnal; largely solitary or in pairs during breeding, but highly gregarious in migration and on wintering grounds, forming large flocks. Courtship involves aerial displays and mutual soaring. Foraging in Costa Rica focuses on aerial hawking or ground pursuit of large insects, often in recently burned or plowed fields. Territoriality is minimal in wintering grounds; extensive seasonal migrations span the Americas.
One of the longest-distance raptors, migrating up to 11,000 km between breeding and wintering grounds.
In non-breeding season, diet shifts heavily to insects, especially grasshoppers.
Often migrates in flocks of hundreds to thousands, a rare behavior among raptors.
Migratory
Decreasing
