- 13.4–17.3 in
- 31.9–39.4 in
- 9.3–19.8 oz
- Slightly smaller than a Red-shouldered Hawk.
- Petite Buse (French)
- Busardo aliancho (Spanish)
- Each fall, hundreds of thousands of Broad-winged Hawks leave the northern forests for South America. They fill the sky in sometimes huge flocks that can contain thousands of birds at a time, and these “kettles” are a prime attraction at many hawkwatch sites. As they move from the broad stretches of North America to narrow parts of Central America their numbers get concentrated, leading people to describe places such as Veracruz, Mexico, and Panama as a “river of raptors.”
- Scientists used satellite transmitters to track four Broad-winged Hawks as they migrated south in the fall. The hawks migrated an average of 4,350 miles to northern South America, traveling 69 miles each day. Once on their wintering grounds the hawks did not move around much, staying on average within a 1-square-mile area.
- Late Pleistocene fossils of Broad-winged Hawks, up to 400,000 years old, have been unearthed in Florida, Iowa, Illinois, Virginia, and Puerto Rico.
- The oldest Broad-winged Hawk on record was a male, and at least 18 years, 4 months old when it was recaptured after sustaining an injury in Florida in 1987. He was later released.
Broad-winged Hawks breed in large deciduous or mixed forests throughout the eastern United States and southern Canada. They usually nest near forest openings and bodies of water, and far from areas of human disturbance. Migrants roost on edges of tropical forests, cloud forests, and in arid tropical scrub. Some immature birds winter in south Florida and the Florida Keys, using mango and avocado groves, as well as undisturbed West Indian hardwood stands on the larger keys. Most Broad-winged Hawks, however, winter in forests and along forest edges from southern Mexico to Brazil and Bolivia, usually preferring upland sites. Some subspecies live year-round on Caribbean islands.
Broad-winged Hawks eat mostly small mammals, amphibians, and insects. They watch for food from perches on tree limbs (often below the canopy and in the forest interior) as well as places such as utility poles near forest edges. When they spot prey, they swoop down to snatch it from the forest floor. They only occasionally hunt on the wing. Their most frequent prey items are frogs, toads, and small rodents, but they have a broad diet that includes invertebrates, amphibians, reptiles, mammals, and birds (mostly nestlings and juveniles). Their invertebrate prey includes mantises, crickets, grasshoppers, caterpillars, ants, junebugs, click beetles, ground beetles, flies, spiders, earthworms, and crabs.
- Clutch Size
- 1–5 eggs
- Number of Broods
- 1 broods
- Egg Length
- 1.8–2.2 in
- Egg Width
- 1.5–1.7 in
- Incubation Period
- 28–31 days
- Nestling Period
- 35–42 days
- Egg Description
- White, creamy, or bluish, with a granulated surface; either unmarked or with variable brown markings.
- Condition at Hatching
- Semi-active and covered with thick white-and-gray down, with open eyes.
The female does most of the nest construction, assisted by the male. They collect dead sticks from the ground and carry them in their talons into the nest tree to build the main structure of the nest. The female brings bark chips and fresh plant sprigs in her beak to build the nest cup. They spend 2-4 weeks building the nest, which occasionally contains materials such as corn husks, moss, grapevine, lichen, feathers, and pine needles. The nest measures 12–21 inches across and 5–12 inches high on the outside, with an inner cup 6–7 inches across and 1–3 inches deep.
Broad-winged Hawks nest in many species of deciduous and coniferous trees, including yellow birch, European larch, white pine, red pine, trembling aspen, white birch, and white oak. The nest is in the lower third of the canopy, usually in the first main crotch of a deciduous tree or on a platform of horizontal branches against the trunk of a conifer. Pairs sometimes reuse their nests from previous years or renovate old nests of other species.
Within the forest Broad-winged Hawks take short flights from branch to branch; they also soar in circles above the canopy during breeding season, probably in territorial defense. Courting birds perform sky-dancing displays in which they circle high in the air and then plummet toward the ground. Some breeding pairs stay together multiple years in a row, while others take new mates each year. They build nests at least half a mile from the next nearest Broad-winged Hawk pair. They defend nesting areas from other Broad-wings, Red-tailed Hawks, Red-shouldered Hawks, and Northern Harriers. Eggs and nestlings are vulnerable to predators such as raccoons, porcupines, American Crows, Great Horned Owls, and black bears. Although Broad-winged Hawks interact only with their mates in the breeding season, during fall and spring migration they form enormous flocks that often include other raptor species, sometimes totaling tens of thousands of individuals.
Broad-winged Hawks are numerous and their populations are stable and slightly increased (particularly in Canada) between 1966 and 2014, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 1.7 million, with 55% spending some part of the year in the U.S., 42% in Canada, and 2% in Mexico. They rate an 8 out of 20 on the Continental Concern Score and they are not on the 2014 State of the Birds Watch List. However, the Puerto Rican subspecies of Broad-winged Hawk is on the Watch List and is listed as Endangered under the Endangered Species Act. The northeastern U.S. gained suitable breeding habitat as it became reforested in the past century, but this benefit could be offset by increasing human development, since Broad-winged Hawks usually nest in large forests away from human activity. Migration numbers dropped in the east in the 1990s, possibly due to population decline or perhaps simply because of a change in migration patterns. The largest threat to this species is habitat destruction, particularly within its wintering range. Hunting was a common practice in the early twentieth century during breeding and migration, and it continues today on the wintering grounds. Individuals that winter in the Florida Keys and hunt along roadsides are vulnerable to vehicle strikes.
- 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.). The Birds of North America Online, Ithaca, New York.
- Crossley, R., J. Ligouri, and B. Sullivan. 2013. The Crossley ID Guide: Raptors. Princeton University Press, Princeton, NJ.
- Haines, A. M., M. J. McGrady, M. S. Martell, B. J. Dayton, M. B. Henke, and W. S. Seegar. 2003. Migration routes and wintering locations of Broad-winged Hawks tracked by satellite telemetry. Wilson Bulletin 115: 166-169.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1).
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- Partners in Flight. 2012. Species assessment database.
- USGS Patuxent Wildlife Research Center. 2015. Longevity records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.
Long-distance migrant. Broad-winged Hawks migrate in large flocks or “kettles” that may contain several individuals or thousands, often soaring on thermal air currents. In the fall many of them pass by the northern and western shores of the Great Lakes and then turn southwest to skirt the Gulf of Mexico. Spring migration is more dispersed, though they concentrate along the southern shores of the Great Lakes and in southern Texas. Some subspecies stay year-round on Caribbean islands.
Find This Bird
Broad-winged Hawks are most easily seen during migration at hawkwatches such as Hawk Ridge, Minnesota, and Hawk Mountain, Pennsylvania. They form sometimes enormous aerial flocks, especially in southern Texas, in Mexico along the Gulf coast in Veracruz, and along the shores of the Great Lakes. If you’re looking for Broad-winged Hawks during summer, go to an eastern or northern forest and listen for their piercing whistles, often given while circling above the forest canopy, when they are easier to see.