Bedford Audubon Society

The Accipters—
Sharp-shinned Hawk, Cooper's Hawk, and Northern Goshawk
By Tait Johansson

Each fall, ridge tops throughout the northeastern United States play host to flights of migrating hawks. The most spectacular of these in our area are the flocks of Broad-winged Hawks that pass through in mid September. But providing the most consistent flight throughout the fall hawk-watching season are the three species in the genus Accipiter, the Sharp-shinned Hawk (shown at left), Cooper’s Hawk, and Northern Goshawk. A steady stream, rather than a flood like that of the Broad-winged Hawks, the accipiter migration stretches from late August into November, with a peak in early to mid October. Catching updrafts above ridges, migrating accipiters are often more easily seen closely than other, higher-soaring hawks. The bulk of our accipiter flight is made up of Sharp-shinned Hawks, with significant numbers of Cooper’s, and a smattering of Northern Goshawks.

The accipiters, the so-called “true hawks,” are structurally adapted for pursuing and catching other birds, and this distinctive structure allows the hawk watcher to identify them as members of this genus. All three accipiters, relative to other birds of prey, have long tails and short, rounded wings. This combination of traits enables these hawks to maneuver through trees and brush after their prey, the long tail acting as a rudder that lets them change direction abruptly, and the bluntness of their wings makes it possible to fly through smaller spaces in the foliage more easily.

Telling the three species apart is usually much harder than identifying a bird as an accipiter. Sharp-shinned Hawks and goshawks will seldom be confused, simply because they differ so greatly in size—sharp-shins range from the size of a Blue Jay to slightly bigger, and Northern Goshawks are about the size of a crow or larger. The main problem is telling the intermediate-sized Cooper’s Hawk from the other two, and this can be very difficult. Even experienced birders make mistakes, and sometimes at fairly close range. Some general guidelines for telling Sharp-shinned and Cooper’s (the two most commonly encountered species here) apart are as follows: on average, Sharp-shinned Hawks have a squared-off or notched tail tip, while Cooper’s Hawks have a rounded end to the tail. When soaring, Sharp-shinned Hawks also show a slight bend in the leading edge of the wing, while the Cooper’s holds the leading edges of its wings straight. This difference in soaring posture gives the Cooper’s a stiff, rigid look, “like a flying cross,” subtly different from the Sharp-shinned’s more curved wing posture.

Further, there is often a difference in the manner in which the two species flap their wings, although using this trait for identification requires much comparative experience with the two species. The Cooper’s Hawk tends to have a stiffer-winged appearance when it flaps compared to the Sharp-shinned, with less movement of the “wrists” of the wings.

One good site in the area for viewing this flight is the hawk-watching platform at the Nature Conservancy’s Butler Sanctuary on Chestnut Ridge Road in Bedford. Whether you become (or already are) an expert in accipiter identification, or are content to let most of them rocket by you unidentified, the autumn migration of these bold hunters is something not to be missed.

You work your way down the evergreen ridges of New Hampshire and into Chester, Vermont where you overnight in a dense clump of red cedars on the edge of a fallow hay field. In the morning, after a quick Junco snack, you take flight. You fly down the woodland ridges of white pine, oak, and maple and over the farmlands of southern New England and New York State. As you course over the treetops, Blue Jays scream with alarm calls at the mere sight of you, and smaller birds freeze so as to go unnoticed. Food is not on your mind right now, migration is. You overnight in Pound Ridge, New York where you have found a large spruce tree behind an old white barn. The nearby farmhouse has a very active and well-stocked birdfeeder. You look for your favorite fare, the Red-breasted Nuthatch this morning, but you wind up dining on what’s available. An unsuspecting and diseased House Finch that has one eye closed up. You take advantage of the House Finch’s handicap. It’s nature’s way of letting only the strong and healthy survive. House Finch is a little chewy, but O.K. for fast food.

You’re on the road again, winging your way south, you avoid Long Island Sound. You don’t like crossing large bodies of water. One half hour later, in the distance and to your left, you see a huge concrete megalopolis, like you’ve never seen before. You thought Nashua, New Hampshire was a big town! You avoid New York City at all costs. Ahead of you is a very wide river, the Hudson. You cross over with little effort and in short order you arrive over New Jersey’s Atlantic Highlands. In the distance you see a thin strip of land called Sandy Hook, and beyond it you see something that gives you pause. A continuous ribbon of golden sand and beyond it, a big blue abyss! You think that going out there is not safe and you fight like the mad against a terrific northwest wind all day to keep away from “Big Blue.” You follow that ribbon of sand all day. You overnight in Tom’s River, New Jersey, and a cold, wet storm front blows through from the north just before dawn. You take an hour or two to dry off, forfeit breakfast in the interest of time and take off. Following the beach and fighting a terrific northwest gale, you put every ounce of energy into fighting the wind to stay over the land. If you fail, you will perish, drowning out at sea to the bluefish’s delight.

Ahead of you, you observe that the beach takes a funny turn near a tan and red lighthouse. In fact, it heads north again! “This can’t be!” you think. “What am I going to do now? I can’t turn headfirst into this northwest gale, I’ll surely blow out to sea! If you fail to maintain your position over land, you’ll be bluefish chum for sure!” Before you complete this thought, you hear a whooshing sound from behind. You turn to look. You see an imposing dark gray and white mass, and two cold dark eyes fixed upon you. What ever it is, it’s headed directly at you at lightning speed, talons extended. You instinctively roll into a vertical dive, tuck in your head and crash through the woodland canopy. You just missed being a female Peregrine’s late afternoon snack. She’s angry that she missed you by mere inches! She’s flown all the way from Greenland in just a week’s time and she’s very hungry. With the Peregrine’s power and aeronautic abilities, she burns calories like the space shuttle burns fuel! She needs to take in sustenance to continue on her long journey to Jamaica, where she will winter. With grace, skill, and ease, she catches her prey in mid air, severs its spinal cord, plucks and devours it all while on the wing. She’s a powerful bird, and she takes full advantage of her abilities. She’s an airborne great white shark.

You’re still alive, back up in the sky and in one piece. When you crashed through the canopy, you could have easily broken your neck by simply hitting one big tree limb. But you, like your sister hitting the window in Maine, are too young and inexperienced to know this. You will be part of the statistical 20 percent of your species that makes it through its first year of life.

You glance down below at this peculiar point of land jutting out into “big blue.” Hungry, tired, and stressed, you dive down and find an inviting holly tree in the backyard of the Cape May Bird Observatory. There is a birdfeeder here. Warblers flit about all around you. They take advantage of the dense, vine entangled cedar, beach plum, bayberry, and live oak. Through your fiery and starved eyes, warblers look like little cocktail franks dancing on beach plum branches. You’re too tired to hunt this evening. You decide that you will stay here a few days given the strong winds, the fact you are surrounded by “big blue,” and the abundance of food here. You figure you might as well rest up for a while, and maybe hunt up one of those tasty little Red-breasted Nuthatches, here in Old Cape May.s

Photo of Sharp-shinned Hawk Courtesy of and Copyright © by Arlene Ripley

Photo of Cooper's Hawk Courtesy of and Copyright © by Rick Paris
rick@rickparis.com   www.rickparis.com

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