Swainson's Hawk (Buteo swainsoni)
- The light-phase adult Swainson's hawk has dark brown plumage with a brown breast and a pale belly. It also has a conspicuous white patch on its throat. When this hawk is perched, its wings are pointed slightly and are longer than its tail. The Swainson's hawk often is seen in migration in vast flocks and, like the northern harrier, it soars with its wings held above the horizontal.
- Life History
Swainson's hawks are gentle birds that live harmoniously with other birds in their nesting habitat. They eat grasshoppers, crickets, and small mammals that they hunt on the ground or catch in midair.
When Swainson's hawks arrive at their nesting sites in March or April, they may return to their original nests as these hawks are noted to be monogamous. Research indicates that they have a high degree of mate and territorial fidelity; however, details are still lacking. Seven to 15 days after the birds arrive, the males begin constructing nests on the ground, ledges or in a trees. The nest consists of twigs and grasses and can take up to two weeks to complete.
After that, the female will lay and incubate two to four white eggs with faint brown marks for approximately 28 days. The male helps with incubation when the female leaves the nest to feed. The young hatch sometime between March and July and do not leave the nest until some 30 days later. The young hawks chase grasshoppers and crickets on the ground before they learn how to catch other kinds of prey.
- Open grassland and desert areas particularly favored by Swainson's hawks.
- They nest across the western United States and Canada, including the western half of Texas.
- The winter migration of the Swainson's hawk is a spectacular sight. They migrate overland in vast flocks that fill the skies with birds and the viewer with awe. From North America through Mexico and Central America to wintering grounds in Argentina, this annual trip is purported to range from 11,000 to 17,000 miles.