Swainson's Hawk
Buteo swainsoni
Summary 7
Swainson's hawk (Buteo swainsoni), is a large Buteo hawk of the Falconiformes, sometimes separated in the Accipitriformes like its relatives. This species was named after William Swainson, a British naturalist. It is colloquially known as the grasshopper hawk or locust hawk, as it is very fond of locusts and grasshoppers and will voraciously eat these insects whenever they are available. There are two main color variations. Over 90% of individuals are light-morph; the dark morph is most common in the far west of the range. Light-morph adults are white on the underparts with a dark, reddish "bib" on the chest and a noticeable white throat and face patch. The underwings, seen as the bird soars, have light linings (leading edge) and dark flight feathers (trailing edge), a pattern unique among North American raptors. The tail is gray-brown with about six narrow dark bands and one wider subterminal band. The upperparts are brown. Juveniles are similar but dark areas have pale mottling and light areas, especially the flanks, have dark mottling. The chest is pale with some darker marks. The subterminal band of the tail is less obvious. Birds in their first spring may have pale heads because of feather wear. Dark-morph birds are dark brown except for a light patch under the tail. There is a rufous variant that is lighter on the underparts with reddish bars. The tails of both these forms resemble those of the light morph. Adults of both of these variants are 18.9 to 22.1 inches in length. The Swainson's hawk has been spotted in the COSA in May.
Sources and Credits
- (c) rbbrummitt, some rights reserved (CC BY-NC), uploaded by rbbrummitt
- (c) lostinfog, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Buteo_swainsoni01.jpg
- (c) Megan McCarty, some rights reserved (CC BY), http://commons.wikimedia.org/wiki/File:Swainson%27s_Hawk,_Megan_McCarty144.jpg
- (c) Tony Hisgett, some rights reserved (CC BY), http://commons.wikimedia.org/wiki/File:Swainson%27s_Hawk_2.jpg
- (c) Tony Morris, some rights reserved (CC BY-NC), https://www.flickr.com/photos/tonymorris/419839373/
- (c) Dominic Sherony, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Swainson%27s_Hawk_(Buteo_swainsoni)_(17026347269).jpg
- Adapted by dirstine from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Buteo_swainsoni
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