Cooper's hawks are medium-sized birds with long, lean bodies. Individuals in the western part of the range are usually smaller than those in the east. Male length ranges from 35 to 46 cm and length of females ranges from 42 to 50 cm. The average mass of males ranges from 280 g in western males to 349 g for eastern males. The average mass of females ranges from 439 g for western females to 566 g for eastern females. Cooper's hawks have a wingspan of 75 to 94 cm.
Adult Cooper's hawks have a dark blackish crown and a lighter colored neck. The back is blue-gray and the tail has several dark bands and a white band at the tip. The eyes of these hawks, like most predatory birds, face forward which gives them good depth perception for hunting and catching prey at high speeds. The hooked bill is important for tearing the flesh of their prey. In flight, Cooper's hawks display a long barred tail and rather short and rounded wings. Cooper's hawks beat their wings quickly and are able to fly very well through heavily wooded areas.
Cooper's hawks can sometimes be confused with sharp-shinned hawks, which are smaller (25 to 35 cm) and have a less distinct dark crown and a tail that is more square in shape. (Chipper Woods Bird Observatory, 1998; Johnsgard, 1990; Peterson and Peterson, 2002; Tufts, 1986)
Cooper's hawks are native to North and Central America. They can be found throughout southern Canada, the United States, and Central America. Many Cooper's hawks are migratory and populations often move north to breed. In most of the United States you can find Cooper's hawks year-round. They migrate to Central America for the winter. (Tufts, 1986)
Cooper's hawks live in deciduous and mixed forests. They also live in open woodland habitats such as woodlots, riparian woodlands, semi-arid woodlands of the southwest United States, and other areas where woodlands are found in patches. (Johnsgard, 1990)
Cooper’s hawks are monogamous, and many pairs mate for life. Pairs breed once per year and raise one brood per breeding season. The male chooses the nest site, but the female does most of the nest-building. Courtship includes flight displays with wings held in a deep arc shape. Cooper’s hawks are territorial, and defend a territory around the nest.
Courtship displays include flight displays. For example, the male will fly around the female showing his under tail feathers to her. He raises his wings high above his back and flies in a wide arc with slow, rhythmic flapping. These display flights usually occur on bright, sunny days in mid-morning, and begin with both birds soaring high on warm rising air. The male and female may both participate in courtship flights. The male begins by diving toward the female, followed by a very slow-speed chase. Both birds move with a slow and exaggerated wingbeats alternated with glides. (Ehrlich, et al., 1988; Johnsgard, 1990; Peterson and Peterson, 2002; Whitfield, 1984)
Cooper's hawks begin their breeding season early in the spring. As early as March, they build nests made of sticks and twigs and lined with bark, conifer needles and down. The female lays 3 to 6 (usually 4 to 5) bluish to greenish-white eggs that are usually spotted. The eggs hatch after 32 to 36 days. The female does most of the incubating, and the male provides food for her. After the eggs hatch, both parents care for the young, who leave the nest after 27 to 34 days when they learn to fly. The parents continue to provide food to the chicks until they learn to feed themselves at about 8 weeks old. Most Cooper's hawks do not breed until they are at least two years old. (Chipper Woods Bird Observatory, 1998; Peterson and Peterson, 2002; Rosenfield and Bielefeldt, 1993; Stoper and Usinger, 1968)
Both male and female Cooper’s hawks care for their chicks. The female performs most of the egg incubation and spends nearly all of her time warming and protecting the nest. The male will protect the nest by defending the area from predators. While the female broods the nest, she has little time to catch her own food so the male will bring her prey that he has caught. After the eggs hatch, both parents will brood, feed, and protect the young chicks. The male however, continues to do most of the hunting. The chicks learn to fly after a few weeks and will leave the nest but remain with their parents. The parents will continue to feed and protect the fledgling chicks until they learn how to feed themselves and survive on their own. (Ehrlich, et al., 1988)
Cooper's hawks are known to live as long as 12 years in the wild. Like many animals, Cooper's hawks are most vulnerable when they are young. Many Cooper's hawks do not survive long after they reach 1 year old. (Rosenfield and Bielefeldt, 1993)
Cooper's hawks rely on eyesight to locate prey, and therefore are diurnal. They spend much of their time sitting on a perch, waiting to ambush passing birds. Cooper's hawks migrate yearly between their summer breeding grounds and their southern winter range. These birds are mostly solitary and will live with a mate only during the breeding season. (Rosenfield and Bielefeldt, 1993)
We do not know much the territory size of Cooper's hawks. However, they do build their nests at least 0.7 to 1.0 km away from their neighbors. (Rosenfield and Bielefeldt, 1993)
Cooper's hawks communicate using vocalizations and displays. They probably use vocalizations more than visual displays, because their dense forest habitat makes it difficult to see visual displays from far away. It is estimated that there are 42 different calls made by females, 22 by males, and 14 by juveniles. Males have higher pitched voices than females. Cooper's hawks rely on their amazing eyesight to locate prey.
Cooper's hawks eat mostly birds and small mammals. However, they also eat reptiles and amphibians when they are available. When hunting, Cooper's hawks usually perch in a hidden location and watch for prey. When they see prey, quickly swoop down and seize it. Bobwhites, starlings, red-winged blackbirds, eastern chipmunks, and squirrels are common prey for Cooper's hawks. Their short, rounded wings make them very maneuverable fliers in dense, forested habitats. These hawks also chase prey on the ground by half running and half flying. The prey taken by an individual Cooper’s hawk depends on its size; larger hawks eat larger prey than smaller hawks.
Cooper's hawks obtain water by scooping water up with their beaks and tipping their heads back to drink. They often nest near rivers or streams and have even been seen in backyard bird baths. They likely obtain water from these sources. (Cybergeo, 1999; Ehrlich, et al., 1988; Rosenfield and Bielefeldt, 1993; Whitfield, 1984)
Adults, nestlings and eggs are vulnerable to predation by great horned owls, red-tailed hawks and northern goshawks. Eggs and nestlings are also vulnerable to predation by raccoons and American crows. (Rosenfield and Bielefeldt, 1993)
Cooper's hawks impact the populations of the animals they prey on. As high level predators they play an important role in keeping many populations healthy. By keeping prey populations down, birds of prey help them to avoid problems such as disease or food shortage which may occur from overpopulation. They are also hosts for several species of lice and intestinal parasites. (Rosenfield and Bielefeldt, 1993)
Cooper's hawks occasionally prey on domestic chickens in poultry farms. However, this occurs rather infrequently and is offset by Cooper's hawks consumption of pest species that can cause significant damage to farmers' crops. (Cybergeo, 1999)
Cooper's hawks are high level predators that help to regulate populations of their prey. Population regulation helps to avoid problems from over population such as disease outbreaks or food shortages. These predators often prey on small mammals like house mice that may be a pest for farmers or homeowners.
Cooper's hawks are sometimes used in the sport of falconry. In falconry, humans will train a hawk to hunt wild game on command. The hawk will bring it's prey back to the human, who will reward the hawk with a different food item and take the fresh prey to cook and eat. (Rosenfield and Bielefeldt, 1993)
Cooper’s hawk populations declined as birds were poisoned by pesticides such as DDT. DDT was banned in 1972, and populations of Cooper's hawks are now recovering. One threat facing Cooper’s hawks today is loss of habitat. Logging and other human activities may destroy the forest habitats that they prefer.
As migratory birds, Cooper's hawks are protected under the U.S. Migratory Bird Act. The Convention on International Trade of Endangered Species (CITES) regulates the capture and international trade of Cooper's hawks. Cooper's hawks are sometimes captured in the wild to be used in the sport of falconry. (Rosenfield and Bielefeldt, 1993)
Tanya Dewey (author), University of Michigan-Ann Arbor, George Hammond (editor), Animal Diversity Web Staff, Rachelle Sterling (editor), Special Projects.
Kari Kirschbaum (editor), Animal Diversity Web Staff.
Vladimir Perepelyuk (author), Fresno City College, Carl Johansson (editor), Fresno City College.
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