Photo by Steve Poole

Swainson's Hawk (Buteo swainsoni)

Fun Fact

Swainson's Hawks will sometimes group up into flocks of thousands during migration.


Both the common and scientific names are after William Swainson, an english naturalist.

Conservation status

IUCN Least Concern


~20 years


A medium sized and slender buteo with two color morphs, belly and chest varying in color from light to dark with long wings and tail. Dark flight feathers are distinctly contrasting with the inner wing. Wing tips reach tail or just past tail when folded.

Photo Courtesy of Steve Poole

Photo Courtesy of Steve Poole


18.9-22 in (45-65 cm)


12.9–14.3 in (36.2cm – 42.7cm)


24.4-48.2 oz (693-1367 g)


Mostly found in the Western US and Southern Canada during summer and in South America, Argentina, Paraguay and Southern Brazil as well as local areas in the US during winter. Most of the population is migratory starting migration during August-early November and returning to North America in late February – April. One of the longest migrations of North American raptors, traveling up to 6,214 miles in two months. Swainson’s Hawks congregate into flocks, sometimes in the thousands during migration. (Range map below)


Found in a variety of open country, grasslands, tundra, and open woodlands. Open habitats from sea-level to about 2,000 meters but found higher during migration.


Mainly small mammals including rabbits, rodents and bats during breeding season. During non-breeding season, insects and invertebrates make up most of their diet with only occasional rodents and birds. Has a variety of hunting techniques, including sitting on a perch, soaring overhead, or walking on the ground.


Solitary or in pairs during breeding season and in flocks during migration. High-circling and calling done over most of territory. Sky-dance usually includes high soaring and diving on partly closed wings and the repeating sequence above the nest.


Season begins in mid April-July in south or in north from June-August/September. Uses a stick nest with grasses often used for repeated years and can grow to 1-1.25 m across and 30-50 cm deep. Nest is lined with grasses, leaves, flowers, lichens and bark. Clutch size is typically 2-3 eggs which are incubated for 34-35 days. Chicks fledge at 42-44 days.

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InfoNatura: Animals and Ecosystems of Latin America [web application]. 2007. Version 5.0 . Arlington, Virginia (USA): NatureServe. Available: (Accessed: October 24, 2012 ).

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