The Broad-winged Hawk is one of very few raptors to be a true long distance migrant. Each fall, the Broad-winged Hawks that breed in the forests of Canada and the eastern United States migrate to their Central or South American wintering grounds, a distance of 3,500 to 4,500 miles (5,600 to 7,200 kilometers). Returning in the spring makes for a round trip of between 7,000 and 9,000 miles (11,200 and 14,400 kilometers) a year. Because the hawks are unable to glide over large bodies of water like the Gulf of Mexico, virtually all of North America's Broad-winged Hawks must pass through Panama, where in 1994, up to 1,400,000 individuals were estimated.
On its breeding grounds the Broad-winged Hawk is a quiet woodland hawk, one of the smallest North America buteos, usually identified by its pale underwings, rufous barred underparts and black and white banded tail.
SIZE
The Broad-winged Hawk is a small to medium-sized buteo, about the size of a crow. Male and female length and wingspan measurements overlap considerably. The average length is 15 inches (38 centimeters) and average wingspan is 34 inches (86 centimeters). Females are heavier with an average weight of 1.0 pound (440 grams) while males average 0.8 pounds (357 grams).
MORPHS
There is a very rare dark morph which occurs most frequently in west-central Alberta and northeastern British Columbia, in the extreme northwest portion of the Broad-winged Hawk's range in North America. Isolated records of dark-morph birds have also occurred throughout its eastern and southern range, but only during migration.
SPECIFIC DESCRIPTION
Adult Light-morph - Perched
- brown head with greenish-yellow or yellow cere
- upperparts uniformly dark brown
- underparts creamy white with variable rufous barring
- rufous often forms solid color on chest, with more obvious barring below
- folded tail with one bright creamy band flanked by two broad black bands
- wing tips reach mid-point of tail
Immature Light-morph - Perched
- light stripe over eye and dark mustache mark
- streaks most evident on side of face, throat, and breast
- upperparts dark brown with light feather edges
- underparts white with brown streaks made up of large brown spots
- light brown-gray tail with darker bands; subterminal band the widest.
SIMILAR SPECIES
The Broad-winged Hawk is superficially similar to both the Sharp-shinned and the Cooper's Hawk, especially from the front. However, they are accipiters characterized as long, slim hawks with comparatively short wings and are very differently shaped than the chunky, crow-sized Broad-winged Hawk. They also show much paler chests and much more heavily barred flight feathers than a Broad-winged Hawk does. In adult plumage, all accipiters have gray or gray-blue backs and wings, while the Broad-winged Hawk has a dark brown back and wings. Immature Broad-winged Hawks can be confused with immature accipiters, including Northern Goshawks, but are much chunkier with long, broad wings and equal width tail bands.
Both a dark morph Gyrfalcon and a dark Peregrine Falcon (immature "Peale's" Peregrine) are about the same size but do not show the broad tail (narrow at the base and wider at the tip unless folded) of a Broad-winged Hawk. Both falcons have generally dark tails, possibly with one or two very thin bands as opposed to the banded tails of adult and immature Broad-wings.
The adult Broad-winged Hawk's tail bands of equal width eliminate confusion with other buteos including the dark-morph Ferruginous Hawk (unbanded all light tail), the dark morph adult "Harlan's" Hawk (a whitish tail marbled with dusk), the dark-morph immature Red-tailed Hawk (many narrow tail bands - subterminal band no wider than others), the dark morph Red-tailed Hawk (red tail), the immature dark-morph Rough-legged Hawk (very broad tail band) and the immature dark morph White-tailed Hawk (pale tail with many very narrow gray bands). The Broad-winged Hawk's generally light underwing with the dark edges, or the dark morph's two-toned underwing with dark edges is distinctive from the dark-morph Swainson's Hawk's underwing (no pale flight feathers and two-toned effect often reversed).
Species most similar to the Broad-winged Hawk are the Red-shouldered Hawk, the Gray Hawk, and the dark-morph Short-tailed Hawk. Compared to a light-morph Broad-winged Hawk, the Red-shouldered Hawk shows distinctive white crescents at the base of the primaries in flight and a red shoulder when seen from above. The immature Broad-winged Hawk can be hard to tell from an immature Red-shouldered Hawk. The immature Red-shouldered Hawk has tawny crescent wing panels, or "windows", and the upper tail surface is dark with light bands while the immature Broad-winged Hawk's is light with dark bands. The adult Gray Hawk has gray barred underparts and gray flecked wing linings, not the rufous barring of the Broad-winged Hawk's underparts and the brown flecked wing linings. The Gray Hawk also shows a white crescent at the base of the uppertail which the Broad-wing does not have. The immature Gray Hawk also shows a white crescent at the base of its uppertail surface. The dark morph adult Short-tailed Hawk is very similar to both the adult and the immature dark morph Broad-winged Hawk but shows secondaries (on the underwing) that have a dusky gray background, causing the white background of the primaries to stand out as an isolated white circle. The adult dark morph Broad-winged Hawk has dark tail bands of equal width. The Short-tailed Hawk shows one broad subterminal band and two to three narrower bands. The immature dark Short-tailed Hawk has small white spots over its lower belly while the dark immature Broad-winged Hawk is generally dark below , perhaps showing a few very thin rufous streaks.
OTHER NAMES
The Broad-winged Hawk is also known as the Broadwing.
ETYMOLOGY
The scientific name Buteo platypterus is translated as "hawk or falcon" (Buteo - Latin) that has a "broad" (platys - Greek) "wing" (pteron - Greek).
MYTHOLOGY
There has been no mythology recorded for this species in North America.
VOICE
The Broad-winged Hawk's most common vocalization is a two note whistle. The first note is short and slightly higher pitched than the longer, plaintive second note. It is commonly transcribed as "Pee-w-e-e-e-e-e" or "Kill-e-e-e-e". The male has a slightly higher voice than the female. This call is heard when intruders approach the nest or when the birds circle over their territory.
A "whining" is given when the male brings food for the female. During copulation the male makes a wheezy two-toned whistle transcribed as "whee-oou." Tiny nestlings peep and hungry fledglings give a piercing whistle somewhat similar to the adult "peewee" call.
