The Cooper's Hawk (Accipiter cooperii) is a medium-sized hawk.

Description

The average adult male, at 312 g (11 oz), 39 cm (15 in) long and a wingspan of 73 cm (29 in), is considerably smaller than the average female, at 500 g (1.1 lb), 45 cm (18 in) long and a wingspan of 83 cm (33 in). All have short broad wings and a long, round-ended tail with dark bands. Adults have a dark cap, blue-gray upperparts and white underparts with reddish bars. They have red eyes and yellow legs. Immatures have brown upperparts and pale underparts with thin streaks mostly ending at the belly. This bird is somewhat larger than a Sharp-shinned Hawk and smaller than a Northern Goshawk, though small males nearly overlap with big female Sharp-shins, and big female Cooper's Hawks nearly overlap with small male Goshawks. The Cooper's Hawk appears long-necked in flight and has been described by birdwatchers as looking like a "flying cross".

This bird was named after the naturalist William Cooper, one of the founders of the American Museum of Natural History in New York.

Taxonomy and systematics

Class: Aves Order: Falconiformes Family: Accipitridae Subfamily: Accipitrinae Genus: Accipiter

Ecology

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. Birds from most of the Canadian and northern-U.S.-range migrate in winter, and some Cooper's Hawks winter as far south as Panama).

Food and feeding

These birds capture prey from cover or while flying quickly through dense vegetation, relying almost totally on surprise. Most prey are mid-sized birds, with typical prey including American Robins, jays, woodpeckers, European Starlings, icterids and doves. Birds preyed on can range in size from wood-warblers to Ring-necked Pheasants. Cooper's Hawks also eat small mammals, especially rodents such as chipmunks and tree squirrels. Mammalian prey can be as small as mice and as large as hares. Other possibilities are lizards, frogs, snakes and large insects. The hawks often pluck the feathers off their prey on a post or other perch. They are increasingly seen hunting smaller songbirds in backyards with feeders. They will perch in trees overlooking the feeders, then swoop down and scatter the other birds in order to capture one in flight.

Nesting

Their breeding habitat are forested areas. The breeding pair builds a stick nest in large trees. The clutch size is usually 3 to 5 eggs. The cobalt-blue eggs average about 48 x 38 mm (1.9 x 1.5 in) and weigh about 43 g (1.5 oz). The incubation period ranges from 30 to 36 days. The hatchlings are about 28 g (1 oz) and 9 cm (3.8 in) long and are completely covered in white down. They are brooded for about two weeks by the female, while her mate forages for food. The fledging stage is reached at 25 to 34 days of age, though the offspring will return to the nest to be fed for up to 4 more weeks. Eggs and nestlings are preyed on, rarely, by raccoons, crows and competing Cooper's Hawks. Adults rarely fall prey to Red-tailed Hawks, Great Horned Owls and Northern Goshawks.

Status and conservation

At one time, Cooper's Hawks were heavily hunted in persecution for preying on poultry and were called "chicken hawks". It is now known that predation by these hawks on domestic animals borders on negligible, and they are rarely hunted these days. Cooper's Hawks' breeding success was also reduced by the use of the pesticide DDT, but the ban of DDT ended that threat. Since then, the adaptable Cooper's Hawk has thrived.

References

• Database entry includes justification for why this species is of least concern
• Sibley, David (2000). The Sibley Guide to Birds. Knopf. ISBN 0-679-45122-6.

External links

• Cooper's Hawk Species Account - Cornell Lab of Ornithology
• Cooper's Hawk - USGS Patuxent Bird Identification InfoCenter
• Cooper's Hawk Information and Photos - South Dakota Birds and Birding
• Cooper's Hawk Wing & Weight data