Buteo swainsoni jamaicensis

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IMG_0080Swainson'sHawk_600.JPG

Buteo jamaicensis – red-tailed hawk, Boulder Valley Ranch, Colorado. Eddie Boosey of Norfolk, England, tells me [apparently incorrectly], “It is Swainson’s buzzard, Buteo swainsoni. You can tell that it is a buzzard because it is called Buteo. In America, however, for some unknown reasons this, like your seven other buzzards, is called a hawk, so it is known as Swainson’s hawk.” Eddie and I are often separated by a common language.

13 Comments

Hi, Matt. This is actually an adult Red-tailed Hawk (Buteo jamaicensis) - note the tail color. ;-)

This is actually an adult Red-tailed Hawk (Buteo jamaicensis)

I haven’t the foggiest idea, but you may see a red-tailed hawk in flight here and a Swainson’s hawk at the link above. To my untrained eye, the wing markings on the red-tailed hawk look very different. I have forwarded this comment to Mr. Boosey.

That is a very nice Red-tailed Hawk. That red tail is a dead give-away! The underside pattern of this bird has almost zero resemblance to a Swainson’s Hawk.…

This looks nothing like a Swainson’s Hawk! For one thing, it has a solid red tail, while a Swainson’s has narrow grey and white bands. The breast markings are also very different.

I assume then that it is a red-tailed hawk and will change the text accordingly. But never tell a person who can barely tell a heron from a redwing (OK, from a cormorant) that it looks “nothing like” a Swainson’s hawk. I can see the difference between the tail markings, but the wing markings on my picture do not look at all like those on the link to the red-tailed hawk. How come?

I can see the difference between the tail markings, but the wing markings on my picture do not look at all like those on the link to the red-tailed hawk. How come?

Hi again. I’m not sure exactly which photo or illustration you were referring to at the Red-tailed link you posted. The illustration shows the dorsal side of the wings, which show very different markings from the ventral side that is seen in the photo of this post. One of the best field marks for Red-taileds is the dark patagial bar. This is the darker area along the leading edge of the wing before the “wrist,” if that makes sense. Swainson’s Hawk lacks this patagial bar. Typically, adult Swainson’s Hawks have a strong contrast between the light-colored coverts and the dark-colored flight feathers, giving the underwing a distinctly two-toned look (see the illustration at the whatbird.com link in the photo caption). Red-tailed lacks this strong contrast and instead typically has dark tips to the flight feathers.

Having said all that, both species have light and dark morphs, and juveniles look different, too. So plumage can vary a lot, and it’s not always easy to compare the two. A couple additional field marks are the wing shape and the presence of a “belly band.” Swainson’s Hawks have much more pointed wing shapes than Red-taileds. Red-taileds have a belly band of spots, which varies in intensity. On the photo posted, the belly band is on the relatively light side.

I hope that helps, btw! I’d be happy to point out other field marks or try to explain it better.

Much more important is the tail!!!!!!! All solid reddish here, no black bands. Very different from Swainson’s Hawk. Tails are critical features in hawks.

It’s a rather unusual red-tail, as the patagium isn’t very dark. A black patagium is the most important field mark of a red-tailed hawk, not all of whom have red tails. But it certainly isn’t a Swainson’s hawk.

This isn’t all that unusual – we see quite a few very light birds that don’t have strong patagials.

I’m not sure exactly which photo or illustration you were referring to at the Red-tailed link you posted. The illustration shows the dorsal side of the wings, which show very different markings from the ventral side that is seen in the photo of this post.

You can see 4 shots of the bird in flight by clicking the thumbnails about halfway down the page, then scrolling up to the expanded shot. “My” bird must be a very light morph, because my untutored eye simply does not see the same pattern on the ventral side of the wings.

Well anyway: Thanks all for the corrections! I have modified the text accordingly.

John Harshman, while not all Red-tails have red tails, if a hawk does have a red tail, like this one, then it is a Red-tailed Hawk. And the previous sentence is an example of why we should all resist the move by book and journal editors to prohibit capitalizing proper names of species.

Feel free to capitalize anything you like, and I will feel free not to.

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This page contains a single entry by Matt Young published on July 1, 2013 12:00 PM.

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