Cooper's Hawk

The Cooper's Hawk (Accipiter cooperii) is a medium-sized woodland raptor native to North America. Known for its remarkable agility and speed, it is a master of navigating dense forest canopies in pursuit of prey. Once severely impacted by pesticide use in the mid-20th century, this resilient raptor has made a dramatic recovery, adapting exceptionally well to suburban and urban environments where backyard bird feeders provide an abundant food source.

Like other members of the genus Accipiter, Cooper's Hawks exhibit extreme reverse sexual dimorphism, with females being significantly larger than males—sometimes up to one-third larger. This size disparity allows breeding pairs to target different categories of prey, reducing competition between mates during the nesting season.

Identifying a Cooper's Hawk requires careful attention to shape, posture, and plumage, especially to distinguish it from the closely related and very similar Sharp-shinned Hawk.

Physical Description

• Adults: Feature a dark blue-gray or slate back, a distinct blackish cap that contrasts sharply with a lighter gray nape, and warm reddish-orange barring on the breast and belly. Their eyes progress from yellow in juveniles to dark orange and deep red in mature adults.
• Juveniles: Have brown upperparts and brown-streaked underparts, with the streaking primarily concentrated on the chest rather than the lower belly.

Key Field Marks & Flight Silhouette

• Tail Profile: The long tail of a Cooper's Hawk is rounded at the tip and features a thick, distinct white band at the trailing edge. This is a critical indicator when distinguishing them from Sharp-shinned Hawks, which have squared-off tail tips with minimal white tips.
• Head Shape: Cooper's Hawks have relatively large heads that project far forward of the wings in flight. They often raise their crown feathers, giving the head a squared-off, blocky appearance.
• Flight Pattern: Flaps are rapid and stiff, followed by a short glide ('flap-flap-glide').

Distinguishing from Similar Species

• Sharp-shinned Hawk (Accipiter striatus): Much smaller on average, though a large female Sharp-shinned can overlap in size with a small male Cooper's. Look at the head: Sharp-shinneds have a smaller, more rounded head that looks recessed in flight, and their dark cap merges continuously into the dark nape without the pale collar break seen in the Cooper's Hawk.

Habitat and Range

Cooper's Hawks are widely distributed across North America, breeding from southern Canada southwards through the contiguous United States and parts of northern Mexico. They are year-round residents throughout most of the lower 48 United States, while populations at the northernmost limits of their range migrate south to the southern U.S. and Central America for the winter.

Environmental Preferences

Historically associated with mature deciduous, coniferous, and mixed forests, Cooper's Hawks have successfully colonized fragmented woodlots, suburban tree canopies, and urban parks. They prefer habitats with tall trees for nesting and adjacent open spaces or forest edges for hunting, making mature suburban neighborhoods with backyard bird feeders highly appealing hunting grounds.

Hunting and Diet

Cooper's Hawks are stealth hunters specializing in medium-sized birds, such as European Starlings, American Robins, Mourning Doves, and jays, as well as small mammals like squirrels and chipmunks. They hunt by perching quietly within dense foliage, launching sudden, explosive ambushes. They are extraordinarily agile in flight, using their long tails like rudders to weave through branches at high speeds.

Vocalizations

Generally silent outside of the breeding season, they produce a series of harsh, nasal alarm calls when defending nests or interacting with mates. The most common call is a rapid, rhythmic kac-kac-kac-kac-kac duration.

Nesting and Breeding

Nests are typically built high in a fork of a tall tree, often a conifer or a large deciduous species, situated on a flat branch or crotch. The nest is a bulky platform made of sticks and frequently lined with bark flakes and green leaves. Females perform most of the incubation, which lasts about 30 to 36 days, while the male does almost all the hunting during this period, bringing food to the female and the growing chicks.