Bird of the Month: Cooper’s Hawk

Adult Cooper’s Hawk. Photo by Jeff Bryant.

By Roger Digges, CCAS Vice-President

This month’s featured bird presents the backyard birder with a conundrum. On one hand, you don’t have to worry about what to put in your feeders to attract this bird. Although it will certainly visit your feeders, it won’t touch anything you put in them. The conundrum is that while they don’t eat your seeds or nuts or suet or mealworms or anything else you feed your birds, they do sometimes eat the birds who do.

Many people who feed birds are horrified when a Cooper’s Hawk kills a bird at their feeder. Years ago when our then pre-school daughter was looking out the window, talking to a bird feeding at one of our feeders...WHAM! A Cooper’s Hawk struck and killed it, and proceeded to eat it right in front of her. It took hours to comfort her. We must remember that hawks and owls and eagles, some of our most beautiful birds, are obligate carnivores. They have to eat meat to stay alive. But they aren’t the only birds who eat other animals. Robins, woodcocks, gnatcatchers, flycatchers, nighthawks, swallows, loons, grebes, mergansers—the list goes on and on—all have to kill to stay alive. Some have argued that, by feeding birds, we endanger their lives. Perhaps. But feeding can occasionally save lives as well. After 40 years of feeding birds in five different backyards, I’ve found that birds that use feeders in areas frequented by Cooper’s Hawks tend to adjust, and over time, fewer birds are taken. Also, while much of the time most birds can forage in the winter on their own and survive just fine (they did so for millennia before we humans started setting feeders out), feeders can make a difference during extreme cold snaps, and after heavy snows or ice storms when either they have a hard time finding enough food to fuel their internal heaters during a long, cold night, or their food is much less accessible.

Named after 19th century American naturalist William Cooper, Cooper’s Hawks are sleek, swift, and agile ambush predators. Often you may see a shadow streak across your yard, perhaps the orange or white flash of its underside, but before you can catch a good look, the bird is either gone or down on the ground with its prey. In flight, Cooper’s Hawks are easily distinguished from Red-tailed Hawks by their relatively slender bodies, long tails, and rapid flight. They tend not to soar like red-tails. Perched Coopers are gorgeous birds. Adults have closely spaced horizontal rusty bars on their fronts, and blue-gray backs. Juveniles have brown backs and vertical brown streaks in the front. So, identifying Cooper’s hawks should be easy, right? Not exactly. The problem is that there is a very similar hawk which may visit your yard or that you may find in the woods. While a male Sharp-shinned Hawk is noticeably smaller than a female Cooper’s, a female sharp-shinned may be the same size as a male Cooper’s. Confusing? Yes. While it is more likely that your hawk is a Cooper’s, particularly in town, it’s not certain. If you’re interested, the Project FeederWatch website has an instructive article on how to tell the two species apart.

You are most likely to find Cooper’s or Sharp-shinned Hawks in woodlands or residential areas with mature trees. Because they are ambush predators, the best time to see them is when they pause from their hunting and perch on a fence or a nearby tree. Coopers nest about 25–50 feet up a 35–75 foot tall tree, often a conifer. The male builds the nest out of sticks with a softer cup built into the bottom. The female incubates the eggs for up to five weeks, the male prudently leaving food for her and their young on a nearby branch, as she won’t tolerate his presence during the incubation or nestling period, which lasts another four to five weeks.

Although Cooper’s Hawks, like most raptors, experienced steep population declines in the 19th and 20th centuries due to persecution of all hawks as chicken stealers (which Cooper’s Hawks were), and from DDT causing the thinning of their eggshells in the 20th century, their numbers have since increased. The North American Breeding Bird Census estimates there are a million Cooper’s Hawks in North America. (And also about a million Sharp-shinned Hawks in roughly the same area, although they are less numerous, or less often seen, in Champaign County.)  

Juvenile Cooper’s Hawk. Photo by Jeff Bryant.