Bird Identification

Cooper's Hawk

What to Listen for

Distinguishing Cooper's hawk from sharp-shinned hawk is a big enough subject that entire book chapters have been devoted to it. What follows is only a brief sketch, but I hope a useful one.

Hawks are not songbirds, but knowing the calls of Coops can help you locate them, especially around their nests. Their most commonly heard sound is a series of cackles, to my ear like the even, repetitive laugh of a flicker beefed up with a bit of the laughing gull's heartier timbre.

What to Look for

Cooper's hawks are crow-sized, with a relatively long tail and rather short, rounded wings. All ages and sexes fly with choppy, quick flaps followed by glides; they may also soar with less frequent flapping. They tend to remain undercover in forested areas but will hunt in more open habitats.

All ages and sexes of Cooper's hawks will be larger than sharp-shinneds, but size can be hard to judge correctly in the field. Compared with sharpies, Coops appear longer-tailed and larger-headed, with a more substantial neck. Cooper's tend to fly with their wings held fairly perpendicular to the body, giving the birds a cross-shaped silhouette.

Sharpies not only have a smaller head and neck, but they usually fly with their wrists thrust forward, lending a somewhat crooked shape to their wings and making the birds at times appear almost headless. Sharpies fly with a snappier, lighter wingbeat—the flight of Coops is heavier and more labored.

Cooper's hawks generally show a more rounded tail tip and have a wider, more obvious white terminal band across the tail tip than do sharp-shinneds, whose tail is more squared off.

Cooper's hawks and sharp-shinned hawks follow the same progression in plumage and show pronounced variation in size by age and sex. Immature birds are brown above and white below with fine brown streaking on the underparts, especially the throat and chest. Adults are slate gray above with underparts barred with reddish orange and white. Adults also have a blackish cap, which is especially dark in males. All ages and sexes show several rather wide, darkish bands across the tail.

Cooper's and sharpies also vary markedly in size, with immature females averaging larger than adult females, which are bigger than immature males. Adult males are the smallest—it's the opposite of many mammals.

Comparing Cooper's with sharpies of the same ages, immature Cooper's tend to be more finely streaked below, with those streaks confined more to the throat and breast—their bellies are whiter. Young sharpies usually show more dark streaking below, continuing lower down on the belly.

Adult Cooper's show a blacker, more contrasting black cap than sharp-shinneds, but in both species males are darkercapped than females.

Finally, if you see a perched bird and you're trying to decide between these two species, look at the back of the crown, right where it meets the top of the nape. Cooper's has a short crest it often erects, which combines with its large, flat head to give it a crew-cut, jar-headed look. Sharp-shinned never shows this—it has a rounded, more seamless transition from crown to nape.

Of course, sharpshinned hawk isn't the only species that can be confused with Cooper's hawk. But if you're wanting to get to know Cooper's hawks, start by learning as much as you can about sharp-shinned, and vice versa.

Where and When to Look

Cooper's hawks are found across southern Canada and just about all over the United States, although they withdraw from the northernmost tier of their range during the winter. They like woods, but on average they hunt in somewhat more open habitats than sharp-shinned hawks. One of the best places to see Cooper's hawks (and sharpshinneds) is around bird feeders.

If you really want to make big strides in your ability to separate the sharpies from the Coops, you should go to a hawk watch site, probably in autumn, although there are active spring counts too. There, you can see a decade's worth of Cooper's and sharpshinneds in a day, and usually get lots of expert help with your identifications. One good source for information on hawk watch sites is the Hawk Migration Association of North America (hmana.org), or you can ask about hawk watches at your local bird club or nature center.

—Jeff Gordon

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