Most hawks are solitary creatures. They are seen in pairs during the breeding season and may gather in small groups at favored hunting grounds but otherwise spend much of their lives alone. And, unlike most birds, the great majority of these predators do not migrate in flocks; three exceptions are native to North America.
The broad-winged hawk, a small buteo with prominent tail bands, is unusual in two respects. In contrast to most buteos, which live and hunt in open country, this crow-sized hawk inhabits deciduous forests where it hunts from a secluded perch for mice, snakes, lizards and small insects. By mid September, broad-wings, which range across the eastern half of the Continent, gather in large flocks and begin their migration to South America. Taking advantage of updrafts along the Appalachian ridges, they may be seen in flocks of a hundred or more; Hawk Mountain, in Pennsylvania, is renowned for these sitings.
Swainson's hawks, large buteos of the American West, also migrate in flocks (though generally in much smaller congregations than the broad-wings). Their southward journey begins by late September and may be observed through October; Argentina is their winter destination. Sharp-shinned hawks, long-tailed accipiters, may also be seen in loose flocks during the fall migration; unlike the above-mentioned buteos, most remain in North America where they strafe parks and neighborhoods, hunting for songbirds.
