The Field Has Eyes

Cooper's Hawk by Ken Weik

The field has eyes,
the wood has ears;
I will look, be silent,
and listen.

– Hieronymus Bosch

The Cooper’s Hawk, Accipiter cooperii, has returned to perch in the Green Ash and scan the creek’s edge for its next meal. These carnivores mainly eat other medium-sized bird species like Robins, Grouse, Mourning Doves, Starlings, Jays, and Northern Flickers, which they stalk at nearby bird feeders. In addition to birds, the Cooper’s Hawk will also make a meal of small mammals.

Cooper’s Hawks usually dwell in forests and woodlands, but our suburb seems nearly as good as their preferred habitat. Regularly seen in parks, quiet neighborhoods, over fields, and at backyard feeders, these hawks build their nests in nearby dense woods of pines, oaks, Douglas-firs, beeches, spruces, and other tree species. The geographical distribution of these hawks range throughout all of North America and their breeding range extends from southern Canada to northern Mexico. During the winter months, hawks from Canada and northern U.S. migrate as far south as Panama.

The male hawk prefers building the nest in trees that grow on flat rather than sloped ground. The nest sits in a tree crotch or on a horizontal branch at a height 25-50 feet above ground. The nest is quite large, measuring 27 inches in diameter and 6-17 inches high with an 8-inch diameter concave depression in its center. Bark flakes and, sometimes, green twigs line the center of the nest.

Cooper’s Hawks fly using an accipiter style: a few stiff wing beats followed by short glides. When in pursuit of prey, the hawk maneuvers through tree branches precisely and powerfully at top speed. During their courtship display, the hawks fly using slow wing beats and then glide by their potential mate with wings held in a V formation. After pairing, males make a bowing display to females and then begin to build their shared nest.

Cooper's Hawk by Ken Weik

Identification of a Cooper’s Hawk can sometimes be tricky because they resemble the Sharp-shinned Hawk in both size and color. The best way to distinguish the difference between the two hawks is to look at their field marks. The key field marks for identification of the Cooper’s Hawk are as follows:

  • plumage-the hawk’s silhouette is barrel shaped, with the chest and hips being of similar size;
  • chest location-The largest portion of the bird’s chest occurs 1/2 way down its body;
  • head and neck size- large and tall, respectively;
  • juvenile marking-thin streaks of color on breast which taper out at the lower belly;
  • leg size-short, thick legs;
  • adult neck- pale nape with a dark cap; and
  • tail shape-square.

This hardy hawk has survived the ravages of DDT use and gone on to flourish in great numbers despite the added loss of their woodland habitat to logging. As I have come to learn, the Cooper’s Hawk is one of the bird world’s most skillful fliers, with the ability to pursue other birds, their prey of choice, racing through cluttered tree canopies at high-speed. When not in pursuit of their prey, they wait patiently near bird feeders for an easy meal. Knowing more about this hawk, makes me think twice about feeding the songbirds with feeders!

Resource

“Cooper’s Hawk.” allaboutbirds.org. Cornell Lab of Ornithology: All About Birds, n.d. Web 8 Jan. 2012.

“Distribution of Cooper’s Hawk.” birdzilla.com. Birdzilla.com: the number one internet birding site, n.d. Web 8 Jan. 2012.

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1 Comment

  1. A “very cool” blog. I’ve read some of your posts and thoroughly enjoyed them. I need to pass your blog along to my son who is an environmental science major at BGSU.

    Reply

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