Hawk

Hawk, common name for many of the birds of prey of the family that also includes the eagles and kites as well as the harriers, which have often also been called hawks. Some members of the family that are called hawks in North America are known as buzzards in Eurasia. In the Americas, some members of the related family of falcons have been called hawks in the past; the peregrine falcon, for example, was known as the duck hawk, and the merlin as the pigeon hawk. The osprey is commonly called the fish hawk (or fish eagle). There is no clear-cut definition of just what constitutes a hawk.

Sometimes called the true hawks are the 48 species of one genus that includes the goshawks and the sparrowhawks (known as sparrow hawks in North America). The northern goshawk is found throughout Europe except for Iceland and Ireland. Some 48 to 58 cm (19 to 23 in) long, it typically has a hunched posture when resting. It is brownish above with blackish bands below and white undertail coverts. The northern sparrowhawk looks like a small goshawk; it ranges from 28 to 38 cm (11 to 15 in). It is found throughout much of Eurasia and North Africa. Both species feed almost exclusively on birds. Two North American representatives of this group are the sharp-shinned hawk and Cooper’s hawk. Both are blue-grey above and mottled reddish-brown below as adults, brown above and streaked brown and white below when young. They differ in details of coloration, but chiefly in size: the sharp-shinned hawk is 25 to 36 cm (10 to 14 in) long, and the Cooper’s hawk is 36 to 51 cm (14 to 20 in) long, females being the larger sex in both. In North America they are the principal avian predators on small birds.

All hawks feed on living prey but tend to specialize partly on the basis of size. Thus, the smallest hawks feed primarily on insects, and the so-called bird hawks choose their feathered prey in accordance with their own relative size. Some hawks prefer cold-blooded animals, such as amphibians and reptiles. The majority feed principally on appropriately sized mammals, although they will take other prey opportunistically.

Most hawks build bulky nests—of twigs, bark, and leaves—high in trees. The eggs are usually white or bluish-white, variably blotched and spotted with shades of brown. The young are covered with white down and are relatively helpless when newly hatched. They grow slowly and are dependent on their parents for food even after they have fledged.

Scientific classification: Hawks belong to the family Accipitridae of the order Falconiformes. True hawks make up the genus Accipiter. The northern goshawk is classified as Accipiter gentilis, the northern sparrowhawk as Accipiter nisus, the sharp-shinned hawk as Accipiter striatus, and Cooper’s hawk as Accipiter cooperii.