This hawk is one of the first species to start migration south, often leaving the breeding grounds in the northern portion of its range in early August. It usually migrates over land, riding the thermals created by hot air rising from the sun-warmed patches of earth. The large flocks formed during migration can contain other raptors and number up to several hundred birds.

Although there is often high mortality during migration, the Broad-winged Hawk is considered to be the most common hawk in North America.

Length: 33 - 38 cm

Physical characteristics:
This species has a light and dark morph. The dark is quite rare. The light adult has dark brown upperparts. The breast is pale with horizontal red markings extending to the belly. There are thick black and white bands on the tail. The dark adult is a dark chocolate brown all over, with whitish flight feathers that are outlined with black and with black and white bands on the tail. The females are larger than the males.

Voice:
Call is a thin, but piercing high-pitched whistle: teee-teee.

Breeding habitat:
This raptor nests in deciduous or mixed deciduous/coniferous forests. It can be found near openings created by roadways, trails or water.

Mating system:
Believed to be monogamous; pair bonds may sometimes last more than one breeding season. One brood is raised per season.

Nest:
The nest is usually located in a crotch of a deciduous tree. Both parents build the nest, but the female may do most of the construction, particularly of the lining. The nest is constructed of sticks, twigs and dead leaves, and lined with bark chips and possibly lichen or green leaves. A pair may renovate or reuse an old nest, or use the abandoned nest of another species like a crow or squirrel.

Eggs:
Usually 2 - 3 eggs are laid in a clutch. The eggs are white to creamy- or bluish-white in color. They may or may not be marked with brown. 49mm (1.9'').

Chick development:
Only the female incubates, while being fed by the male. Incubation lasts 28 ? 31 days. Chicks are born semialtricial. The female broods, but will resume hunting after one or two weeks. The chicks fledge at about 41 days. At seven weeks old the young are able to catch their own prey.

Diet:
This raptor hunts from a perch or searches for prey during flight. Its diet includes insects, amphibians, reptiles, small mammals and nestling birds. It often forages for food in the very tops of trees while flying low over the forest canopy.

Distribution:
Breeding: The Broad-winged Hawk breeds from the southeastern corner of Canada south throughout the eastern half of the United States.
Winter: The Broad-winged Hawk is one of the few raptors that migrates in flocks (called kettles). These flocks can become quite large. This species is a neotropical migrant winters from southern Mexico and Central America to northern South America. Some immature birds will winter over in south Florida and the Keys.

In Park: The Broad-winged Hawk is a fairly common breeding bird species in the Park and is commonly seen during spring and fall migration. This hawk is most common at lower elevations in the Smokies, but may be observed throughout the Park. A survey of breeding birds in the Park, performed from 1996-1999, ranked Broad-winged Hawk as the 52nd most abundant species out of 113 species observed during the breeding season. Estimates from this survey indicate that overall Broad-winged Hawk density in the Park during the breeding season is approximately 0.0048 pairs per hectare.

References:

Alsop, F. J. III. 1991. Birds Of The Smokies. Great Smoky Mountains History Association, Gatlinburg, Tennessee.

Committee on Classification and Nomenclature of the American Ornithologists' Union. 2002. Forty-third supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 119: 897-906.

Committee on Classification and Nomenclature of the American Ornithologists' Union. 1998. Check-list of North American Birds: the Species of Birds of North America from the Arctic through Panama, including the West Indies and Hawaiian Islands, 7th ed

Ehrlich, P. R., D. S. Dobkin, and D. Wheye. 1988. The Birder's Handbook: a Field Guide to the Natural History of North American Birds. Simon and Schuster, Inc., New York.

Elphick, C., J. B. Dunning, Jr., and D. A. Sibley, eds. 2001. The Sibley Guide to Bird Life and Behavior. Alfred A. Knopf, New York.

Goodrich, L. J., S. C. Crocoll, and S. E. Senner. 1996. Broad-winged Hawk (Buteo platypterus). In The Birds of North America, No. 218 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC: The American Ornitholog

Gough, G. A., Sauer, J. R., Iliff, M. Patuxent Bird Identification Infocenter. 1998. Version 97.1. Patuxent Wildlife Research Center, Laurel, MD. http://www.mbr-pwrc.usgs.gov/id/framlst/infocenter.html.

Sibley, D. A. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.

Stupka, A. 1963. Notes on the Birds of the Great Smoky Mountains National Park. University of Tennessee Press.

Committee on Classification and Nomenclature of the American Ornithologists' Union. 2000. Forty-second supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 117: 847-858.