Broad-winged Hawks are small buteos that breed in deciduous woodlands throughout North America, but are generally secretive. They are uncommon west of Minnesota, and nearly absent throughout the Great Plains. Dark-morph birds are only known to breed in western North America, and are presumed rare. Broad-winged Hawks hunt mainly reptiles and amphibians from a low perch below the forest canopy. They also eat mice, other small mammals, birds, and insects when available.
During migration, Broad-winged Hawks group together by the thousands, forming a tornado-like vortex known to hawk watchers as a 'kettle' or 'boil'. Sometimes there are so many in one group it's impossible to count, and estimating is the only option! To witness this phenomenon is one of the most thrilling events in hawk watching. Even experienced hawk watchers wonder how some Broad-wingeds don't run into each other as they tightly circle together by the thousands. Broad-winged Hawks are vocal mainly on the breeding grounds; their call is a high, thin, drawn-out two-part whistled "ps-eeeeee." Male and female Broad-winged Hawks are essentially equal in size.
Chunky, and compact with large head and bulky chest.
Stocky wings but pointed at the tips in all postures.
In a glide the wings are angular with the tips barely past the back edge.
Tail is narrow, appearing somewhat long (accipiter-like) when closed.
Perched, appears small and stocky with short wings and large heads.
Steady fliers, except in extreme winds.
Soar in tight circles compared to larger raptors.
Soar with wings flat or slight dihedral; wings slightly drooped when gliding.
Flaps are 'snappy' similar to Red-shouldered or Cooper's Hawk, but stiffer or 'choppy' in comparison.
Occurs in a light or dark morph with two age classes, adult and juvenile. Male and female look alike.
Eye color of juvenile is pale yellow-brown, turning dark brown as adults.
Adult light-morph is dark brown above, and pale underneath with a rufous-barred chest (and sometimes belly). The barring is faint on some and nearly solid on others. The flight feathers have a dark trailing edge to the wings. The tail is distinctly banded black & white (white bands thinner).
Juvenile light-morph is whitish below and almost unmarked below to heavily streaked. Some show streaking only on the sides of the breast. The tail has faint, narrow bands with a broad dark sub-terminal. The primaries show a faint, rectangular translucence from below. The back edge of the wings lacks a blackish border.
Dark-morph adults have blackish bodies and underwing coverts. They are similar to light-morphs on the upperside. Juveniles can be solidly dark or show some pale streaking on the underside. The flight feathers are identical to those of light birds.
Utilize thermals and wind to keep them aloft during migration.
Seek lift in groups; when weather conditions are optimal, massive groups can form where the topography 'funnels' or concentrates them.
Spring migration in North America occurs primarily from April through May, with the peak typically in late April (but ~2 weeks earlier in the south). The southern shore of the Great Lakes and parts of Texas are best for seeing lots of Broad-winged Hawks in spring.
The bulk of fall migration occurs from mid-September to early October, but up to 2 weeks later in the southern U.S. Sites to see large numbers of Broad-winged Hawks in fall are the northern shores of the Great Lakes, the Appalachian Mts., and Corpus Christi & Smith Point in south Texas.
The largest Broad-winged Hawk migration (and raptor flight in general) in the world takes place in Veracruz, Mexico where over a million can be seen each fall.
(Map from Cornell Lab of Ornithology's All About Birds. For dynamic distribution maps, visit the eBird website.)