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By Tanya Dewey
Geographic Range
Cooper's hawks are native to the Nearctic and Neotropical regions. They can be found throughout southern Canada and the United States. They winter as far north as the northern United States and southern Ontario, and as far south as Costa Rica. (Tufts, 1986)
Biogeographic Regions:
nearctic 
(native ); neotropical (native ).
Habitat
Coopers hawks are closely associated with deciduous and mixed forests and open woodland habitats such as woodlots, riparian woodlands, semiarid woodlands of the southwest, and other areas where the woodlands occur in patches. (Johnsgard, 1990)
These animals are found in the following types of habitat:
temperate ; terrestrial .
Terrestrial Biomes:
savanna or grassland ; chaparral ; forest .
Physical Description
(13.78 to 19.69 in; avg. 15.35 in)
(29.13 to 37.01 in)
Cooper's hawks are medium-sized birds with long, lean-bodies. Individuals in the western part of the range tend to be smaller than those in the east. Male length ranges from 35 to 46 cm and length of female 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 that is noticeably set off from a lighter nape. They have a blue-gray back and a tail that is crossed by several dark bands and has a distinct white band at its tip. In flight, Cooper's hawks exhibits a long barred tail and rather short and rounded wings.
The eyes of this hawk, like most predatory birds, face forward, giving it good depth perception for hunting and catching prey while flying at high speeds. The hooked bill is well adapted to tearing the flesh of prey. A swift flyer, the Cooper's hawk has a rapid wingbeat and is able to negotiate heavily vegetated woodland habitats.
Cooper's hawks can be easily confused with sharp-shinned hawks, which are smaller (25 to 35 cm) and have a less distinct dark crown and a tail that is square at the tip, unlike the rounded tip of the Cooper’s hawk’s tail. Cooper’s hawks also exhibit slower, stiffer wingbeats than sharp-shinned hawks. (Chipper Woods Bird Observatory, 1998; Johnsgard, 1990; Peterson and Peterson, 2002; Tufts, 1986)
Some key physical features:
endothermic ; bilateral symmetry .
Sexual dimorphism: female larger.
Reproduction
Cooper's hawks breed once yearly
Cooper's hawks begin breeding as early as March.
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 the majority of the nest-building. Courtship activities include stylized flights with the wings held in a deep arc. Cooper’s hawks are territorial, and defend a territory around the nest.
Courtship activities include flight displays. For example, the male of a pair will fly around the female exposing his expanded under tail coverts to her. The male raises his wings high above the back and flies in a wide arc with slow, rhythmic flapping. Typically these display flights occur on bright, sunny days in midmorning, and begin with both birds soaring high on thermals. 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 in which the wings are held at a dihedral angle and the white under tail coverts are conspicuously spread. (Ehrlich, Dobkin, and Wheye, 1988; Johnsgard, 1990; Peterson and Peterson, 2002; Whitfield, 1984)
Mating systems:
monogamous .
Cooper's hawks begin breeding as early as March. Most individuals do not breed until they are at least two years old. Pairs 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 and soon become stained in the nest. The eggs hatch after 32 to 36 days, during which time they are incubated primarily by the female. During this time, the male provides most of the food for the female. After the eggs hatch, both parents tend the young who leave the nest after 27 to 34 days. Parents continue to provide food until the young become independent at about 8 weeks. (Chipper Woods Bird Observatory, 1998; Peterson and Peterson, 2002; Rosenfield and Bielefeldt, 1993; Stoper and Usinger, 1968)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous .
Both male and female Cooper’s hawks care for their chicks. During incubation, the female spends most of the time protecting the eggs and nest, and the male provides nearly all of her food. After hatching, both parents tend the young. The male continues to do most of the hunting during the hatchling stage. Both parents continue to provide food to the chicks until they become independent at about 8 weeks. (Ehrlich, Dobkin, and Wheye, 1988)
Parental investment:
altricial ; pre-fertilization (provisioning); pre-hatching/birth (provisioning: male, protecting: male, female); pre-weaning/fledging (provisioning: male, female, protecting: male, female); pre-independence (provisioning: male, female, protecting: male, female).
Lifespan/Longevity
Cooper's Hawks are known to live as long as 12 years in the wild. However, one study showed that the average age at death was as low as 16.3 months for wild Cooper's hawks. (Rosenfield and Bielefeldt, 1993)
Behavior
Cooper's Hawks 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 more southerly winter range.
Little is known about the degree of territoriality among Cooper's hawks. However, they do appear to maintain a minimum distance between nests of 0.7 to 1.0 km.
Key behaviors:
arboreal ; flies; diurnal ; motile ; migratory ; territorial .
Communication and Perception
Cooper's Hawks communicate using vocalizations and displays. They probably use vocalizations more than visual displays, because their dense forested or woodland habitat prevents visual displays from being seen very far away. One study recorded 42 different calls made by females, 22 by males, and 14 by juveniles. Males have higher pitched voices than females.
Food Habits
Cooper's hawks are predators primarily of birds and small mammals. They also occasionally feed upon reptiles and amphibians. When hunting, Cooper's hawks usually perch in a hidden location and watch for prey. They wait until their prey is unaware of their presence, then quickly swoop down and seize it. Bobwhites, starlings, blackbirds, chipmunks, and squirrels are common prey for Cooper's hawks. Their short, rounded wings make them very maneuverable flyers in dense, forested habitats. These hawks also pursue prey on the ground, half running and half flying. The prey taken by an individual Cooper’s hawk is largely influenced by the size of the bird; larger hawks eat larger prey than smaller hawks.
There is no information available regarding how Cooper's hawks obtain water. (Cybergeo, 1999; Ehrlich, Dobkin, and Wheye, 1988; Rosenfield and Bielefeldt, 1993; Whitfield, 1984)
Primary Diet:
carnivore (eats terrestrial vertebrates).
Animal Foods:
birds; mammals; amphibians; reptiles.
Predation
- red-tailed hawks (Buteo jamaicensis)
- northern goshawks (Accipiter gentilis)
- raccoons (Procyon lotor)
- American crows (Corvus brachyrhynchos)
- great horned owls (Bubo virginianus)
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)
Ecosystem Roles
Cooper's hawks impact the populations of the animals they prey on. They are also hosts for several species of parasites, including larval dipterans, mallophagial lice, tapeworms and helminths. (Rosenfield and Bielefeldt, 1993)
Economic Importance for Humans: Negative
Cooper's hawks occasionally prey on domestic chickens in poultry farms. (Cybergeo, 1999)
Economic Importance for Humans: Positive
Cooper's Hawks prey on wild birds and rodents, which helps keep these populations in check.
Ways that people benefit from these animals:
controls pest population.
Conservation Status
IUCN Red List: [link]:
Least Concern.
US Migratory Bird Act: [link]:
Protected.
US Federal List: [link]:
No special status.
CITES: [link]:
Appendix II.
State of Michigan List: [link]:
Special Concern.
Cooper’s hawk populations declined as a result of the use of pesticides such as DDT, but have begun to recover since DDT was banned in 1972. One threat facing Cooper’s hawks today is degradation and loss of habitat. Management activities such as logging may make former habitat unsuitable for breeding.
Cooper's hawks are protected under the U.S. Migratory Bird Act and CITES Appendix II. They are listed under CITES Appendix III in Costa Rica. In Michigan, they are listed as a species of special concern. (Rosenfield and Bielefeldt, 1993)
For More Information
Find Accipiter cooperii information at
Contributors
Tanya Dewey (author), Animal Diversity Web, University of Michigan Museum of Zoology.
Kari Kirschbaum (editor), Animal Diversity Web Staff.
Vladimir Perepelyuk (author), Fresno City College.
Carl Johansson (editor), Fresno City College.
