Buteo swainsoni
| This dainty, soaring hawk is the most common summer raptor in open areas east of the Rockies. Occasionally, individuals drift into low-elevation fields and meadows in the mountains to hunt for small rodents. The Swainson's Hawk migrates the farthest of the raptors found in the Rockies: these narrow-winged hawks winter as far south as the southern tip of South America. Unfortunately, the heavy use of insecticides in Latin America recently caused a massive die-off of this species. This hawk bears the name of Englishman William Swainson, an early 19th-century illustrator of natural history. | I.D.: Sexes similar. General: long, narrow wings; fan-shaped tail. Light phase: dark bib; white wing linings; dark flight feathers; white belly; finely barred tail. Dark phase: dark wing linings blend with brown flight feathers; brown overall. In flight: conspicuous wing linings and bib; wings are held in a shallow V. Size: Male: L 19-20 in. (48-51 cm); W 52 in. (132 cm). Female: L 20-22 in. (51-56 cm); W 52 in. (132 cm). Range: locally common to uncommon throughout the Rockies east of the Continental Divide. Habitat: open fields, grasslands, sagebrush shelter belts and riparian and agricultural areas. Nesting: often in solitary trees in open fields; builds a large stick nest; often uses the abandoned nests of other raptors, crows, ravens or magpies; uses the same nest repeatedly; female incubates 2-3 eggs for about 28-35 days. Feeding: dives for voles, mice and occasionally ground squirrels; also eats snakes, small birds and large insects, such as grasshoppers and crickets. Voice: high, weak keeeaar. Similar Species: Red-tailed Hawk: wings are held flat when soaring; bulkier overall; lacks the light wing linings and the dark flight feathers. Falcons: pointed wings; long, narrow tail. |