Species: Broad-winged Hawk
Scientific name: Buteo platypterus
Status: Least Concern; Migratory
Broad-winged Hawks are our smallest buteo, or “soaring” hawk. That being said, they still show the classic buteo characteristics: sturdy, sometimes “bulky” bodies, broad wings and tails. All in all, their name is very apt. This species can be seen in two different morphs: light and dark. An adult light morph, which is most commonly seen, has a brown head, back and wings and a lighter front. When observing plumage in flight, keep in mind you want to be looking for dark upperparts, light underparts and diagnostic wing borders. Also, watch for stiff wing beats. These hawks have variable reddish-brown barring and streaking on the neck and chest. Juveniles will have a significantly higher amount of white plumage than adults, with nearly all-white throats. Reddish-brown barring will continue in adults to their underwing coverts. The remaining flight feathers are light underneath with a dark border. Tails have a thick white band. The more uncommon Dark Morph is entirely dark brown, appearing almost black in the back. Their tail resembles that of the Light Morph with the thick white band. The underside of their wings is lighter in colour being silvery grey, contrasting greatly with their dark backs. They also have that diagnostic dark black edge on their flight feathers.
Throughout its range, Broad-winged Hawks can be found in their preferred woodland settings. They breed in deciduous or mixed-wood forests of Canada, stopping in similar habitats as it migrates across North America from its wintering grounds: tropical forests of Central and South America. Broad-winged Hawks range through Canada, as far west as central Alberta and as far north as central Quebec (Gulf of St. Lawrence); migrates through the United States, sometimes wintering in southeastern states. Winters mainly in Central and South America; as far south as Bolivia. Dark morphs nest in western Canada.
Breeding pairs form after migration has ended and they have arrived at the nesting grounds, which is around mid-April to early June depending on location. You may have the opportunity at this time to observe courtship flights – a kind of flying that is often associated with dancing or tumbling. Nests are built in trees and are often lined with pieces of bark. May be built on old crow or squirrel nests. Clutches range in size from 1-5 eggs, most often 2-4. Fledging happens after about one month and will begin to hunt at that age. However, they remain dependant on their parents for as long as a month following fledging.
Hunting by diving from the canopy, prey includes mainly small mammals and amphibians but will also take birds, reptiles, and large insects. Being a “sit-and-wait” predator, they will take a preferred perch and scan its surroundings searching for prey. Frogs play a prominent role in sustaining their diet and so gives us an idea of how they may proceed during migration and go on to choose breeding grounds. Furthermore, their ability to catch prey “on wing”, or during flight, demonstrates sustenance during migration (i.e. large insects eaten on wing without having to stop.)
Threats to species:
Deforestation, habitat fragmentation, and use of pesticides affect the Broad-winged Hawk most severely. Decline in amphibian species due to various terms has impacted this species as well.
Threat to humans:
Little to none. Caution must be taken during migration as they move in such great numbers.
Broad-winged Hawks are best known for their incredible migrations. In the winter they completely abandon their bredding grounds, moving in the ten and sometimes hundreds of thousands in groups called “kettles”. The Great Lakes provide some of the greatest viewing opportunities for these events.
Broad-winged Hawk pairs will often line their nests with green twigs for decoration.
Broad-winged Hawks have very unintimidating calls, give them a listen!
The Cornell Lab of Ornithology. (n.d.). Broad-winged hawk. Retrieved from http://www.allaboutbirds.org/guide/broad-winged_hawk/lifehistory
Alderfer, J. (2006). Broad-winged hawk. Retrieved from http://animals.nationalgeographic.com/animals/birding/broad-winged-hawk/
Boreal Songbird Initiative. (n.d.). Broad-winged hawk. Retrieved from http://www.borealbirds.org/birdguide/bd0097_species.shtml
Alderta ESRD. (2009, December 30). Broad-winged hawk. Retrieved from http://srd.alberta.ca/FishWildlife/WildSpecies/Birds/LargeHawksEagles/BroadwingedHawk.aspx