Swainson's Hawk

Feeding Behavior

May hunt by soaring over grassland, or by perching and scanning the ground. Skilled at catching flying insects in the air. When feeding on insects in fields, may catch them by running about on ground. May concentrate near grass fires, watching for prey driven into the open by the flames.

Eggs

2-3, sometimes 1 or 4. Pale bluish white fading to dull white, usually lightly spotted with brown. Incubation is almost all by the female, about 34-35 days. Male brings food to female during incubation period. Young: Both parents bring food for young, but at first female may remain with young much of time while male hunts. Young can fly about 42-44 days after hatching; may remain with parents until fall migration.

Young

Both parents bring food for young, but at first female may remain with young much of time while male hunts. Young can fly about 42-44 days after hatching; may remain with parents until fall migration.

Diet

Mostly small mammals and reptiles in early summer, large insects at other seasons. When feeding young, preys on ground squirrels, pocket gophers, mice, snakes, lizards, small birds; sometimes bats or carrion. At other seasons, diet shifts to mostly large insects. May feed heavily on grasshoppers and caterpillars in late summer. In winter in Argentina, follows and feeds on swarms of nomadic dragonflies.

Nesting

In courtship, members of pair engage in display flights, with circling and steep dives. On prairies with scattered groves of trees, may have conflicts with Great Horned Owl where both species attempt to nest in same grove. Nest site is usually in a tree or large shrub in open country, usually 15-30' above ground, but may be lower or higher; generally well hidden within foliage. May be built on top of old magpie nest. Sometimes nests on ledge of cliff or steep slope. Nest is a platform of sticks, lined with finer twigs, weeds. Often adds leafy green branches to nest.