Coopers Hawk (Accipiter cooperii)
Among the bird world’s most skillful fliers, Cooper’s Hawks are common woodland hawks that tear through cluttered tree canopies in high speed pursuit of other birds. You’re most likely to see one prowling above a forest edge or field using just a few stiff wingbeats followed by a glide. With their smaller lookalike, the Sharp-shinned Hawk, Cooper’s Hawks make for famously tricky identifications. Both species are sometimes unwanted guests at bird feeders, looking for an easy meal (but not one of sunflower seeds). Other common names; Big Blue Darter, Chicken Hawk, Hen Hawk, Mexican Hawk, Quail Hawk, Striker and Swift Hawk.
The average size of an adult male ranges from 220 to 410 g (7.8 to 14 oz) with a length between 35 and 46 cm (14 and 18 in). The adult male is significantly smaller than the average female, which weigh 330 to 700 g (12 to 25 oz) and measure 42 to 50 cm (17 to 20 in) long. Its wingspan ranges from 62 to 94 cm (24 to 37 in)
Adults have red eyes and have a black cap, with blue-gray upper parts and white underparts with fine, thin, reddish bars. Their tail is blue gray on top and pale underneath, barred with black bands
Immature have yellow eyes and have a brown cap, with brown upper parts and pale underparts with thin black streaks mostly ending at the belly. Their tail is brown on top and pale underneath, barred with dark bands.
Their breeding range extends from southern Canada to northern Mexico. They are generally distributed more to the south than the other North American Accipiters, the Sharp-Shinned Hawk and the Northern Goshawk.
Cooper’s Hawks are forest and woodland birds, but our leafy suburbs seem nearly as good. These lanky hawks are a regular sight in parks, quiet neighborhoods, over fields, at backyard feeders, and even along busy streets if there are trees around.
Cooper’s Hawks mainly eat birds. Small birds are safer around Cooper’s Hawks than medium-sized birds: studies list European Starlings, Mourning Doves, and Rock Pigeons as common targets along with American Robins, several kinds of jays, Northern Flicker, and quail, pheasants, grouse, and chickens. Cooper’s Hawks sometimes rob nests and also eat chipmunks, hares, mice, squirrels, and bats. Mammals are more common in diets of Cooper’s Hawks in the West.
Males typically build the nest over a period of about two weeks, with just the slightest help from the female. Nests are piles of sticks roughly 27 inches in diameter and 6-17 inches high with a cup-shaped depression in the middle, 8 inches across and 4 inches deep. The cup is lined with bark flakes and, sometimes, green twigs.
Cooper’s Hawks build nests in pines, oaks, Douglas-firs, beeches, spruces, and other tree species, often on flat ground rather than hillsides, and in dense woods. Nests are typically 25-50 feet high, often about two-thirds of the way up the tree in a crotch or on a horizontal branch.
References: Wikipedia, Cornell Lab of Ornithology