Distinguishing our two common ‘bird hawks’ can be confusing

Written by Jack Sanders
Thursday, 04 March 2010 14:11

Two of the half dozen or so hawks often seen in our area are “accipiters,” so-called “bird hawks” or, as they are often known elsewhere in the world, sparrowhawks. Rather than capturing slower-moving mammals that the larger hawks favor, they pursue their own. They can catch birds on the wing, no easy feat.

The generic name, accipiter, is a Latin word for hawk, said to come from the words for “take” and “after,” an apparent reference to this group’s famed ability to chase prey. Our three accipiters are the Sharp-shinned Hawk, Cooper’s Hawk, and the Northern Goshawk. The first two are much more apt to be seen and are really bird hawks — the larger goshawk tends to feed on bigger, slower prey, though it may go after a duck or a crow.

The Sharpie is our smallest hawk, running from 10 to 14 inches in length, around the same size as a Blue Jay. A Cooper’s can be 14 to 20 inches, around the same size as a crow. However, telling the two species apart is not easy.

The plumages of both birds are very similar, so much so that even with a good photo such as the one accompanying this article, identification is difficult. Adding to the problem, notes naturalist and author Ed Kanze, is the fact that “Size is suggestive but not reliable in all cases because a female sharpie can be larger than a male Cooper’s.”

One difference might be called “tell-tail.”  A Cooper’s Hawk has a rounded tail, while a Sharp-shinned is square-shaped — a difference that is most notable in the air if the bird is overhead but can also been noticed in a perched bird.

Unfortunately, for identification purposes, a bird hawk may be moving too fast to notice fine points. An experienced hawk-watcher can tell them apart by their wing beats. In his Guide to Birds, David Allen Sibley says, “Cooper’s wing beats are stiffer and shallower, while Sharp-shinned’s are deeper, with more flicking ‘wrist action.’”

The wings of these two species are shorter compared to many larger hawks, called buteos, such as the Red-tailed. That’s because they prey on flying birds. They pursue agile prey and must be at least equally agile to catch a bird on the wing, especially through the maze of obstacles presented by woods.

While Sharpies sit and watch for prey, many other hawks search out food from high in the sky, often gliding through the air. Their long, broad wings are designed to keep them aloft with relatively little effort as they inspect the ground below. They must swoop down on prey only in open areas, such as fields; their wings could not maneuver well in tight spaces like forests.

The Sharpie or Cooper’s Hawk also has a noticeably longer tail than the larger buteo hawks, helping enable it to perform those sometimes-acrobatic chases through the woods.

Be it Sharpie or Cooper’s, seeing a bird hawk chase down another bird is a pretty exciting sight. Winter may be the best hunting season for these hawks. The trees are free of leaves and dinner is out in the open, ready for the plucking. For the same reason, winter can be the best time to witness “bird hawks” in action.

One winter day about 15 years ago, I saw a bird flash by the picture window in our bedroom and a split second later, a second bird went by. Both were moving so fast, I had no clue what they were, but thinking it might have been a chase, I went around to the other side of the house where the two had been headed. Sure enough, on the snow-covered ground was a Sharp-shinned Hawk with a Downy Woodpecker in its talons.

Often a Sharpie or Cooper’s will be seen perched near a backyard birdfeeder. People sometimes feel guilty when they watch a hawk capture a bird attracted to their feeders. Don’t. If the hawk hadn’t gotten its meal at your feeder, it would have found it somewhere else. Your feeder just makes it a tad more convenient for nature to take its course.

After all, like it or not, it’s a bird-eat-bird world out there.

Coming up

The King and the Wanderer, program by Larry Fischer, raptor expert, on the Great Horned and Northern Saw-whet Owls, Thursday, March 11, 6:30 to 7:30, $12/$10, New Pond Farm, 101 Marchant Rd. Redding, 203-938-2117

Bird House Workshop, bluebirds, wrens, swallows, owls, Saturday, March 13, 2 -3:30 pm Audubon Greenwich, 613 Riversville Road, RSVP 203- 869-5272 x221, Greenwich.audubon.org.

Hummingbirds: Our Feathered Gems, with Gina Nichol, Sunday, March 14, 3:30 to 4:30 p.m., Audubon Greenwich, 613 Riversville Road, 203- 869-5272 x230, Greenwich.audubon.org.

Connecticut Ornithological Association annual meeting, four top speakers on all things ornithological, Saturday, March 20, 8 to 4, Chapman Hall, Middlesex Community College campus in Middletown, ctbirding.org

Woodcock Watch, search for one of the rites of spring, Saturday, March 20, 6:45-7:45 p.m. Audubon Greenwich, 613 Riversville Road, RSVP 203-869-5272 x221, Greenwich.audubon.org

Saturday Morning Bird Walks with Luke Tiller; to register, sunrisebirding.com/walks.htm; 203- 453-6724, This e-mail address is being protected from spambots. You need JavaScript enabled to view it

First Sundays, birding at Greenwich Point with Meredith Sampson of Wild Wings, and other guides, 203-637-9822.

Copyright 2010 by Jack Sanders. Send sightings or comments to: jackfsanders [at sign] yahoo.com, or to Bird Notes, Box 1019, Ridgefield, CT 06877; or call 203-438-1183, extension BIRD (2473), and leave a message with your report, spelling your first and last names and telling us your town. If you need help identifying a bird, try your local nature center. If you find an injured bird, call wildlife rehabilitator Darlene Wimbrow of Redding, 203-438-0618, Wildlife in Crisis of Weston, 203-544-9913, or Wild Wings of Greenwich, 203-637-9822. The columnist’s website is www. sandersbooks. com.

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