Hawk refers to any of a group of birds of prey. Hawks have large eyes, hooked beaks, and sharp claws for detecting, capturing, and consuming animals. They belong to a family of over 200 birds that also includes ospreys, kites, harriers, Old World vultures, and eagles. Hawks live on every continent except Antarctica. 
Goshawk
There are two basic types of hawks: (1) accipiters, or ambushing hawks, and (2) buteos, or soaring hawks. Accipiters include goshawks and sparrowhawks. Members of this group watch and wait for prey from a perch before rapidly chasing after the prey. Accipiters commonly inhabit forests, where their relatively short wings and long tails enable them to maneuver well. Buteos live mainly in open grasslands and in deserts. Most species have long, broad wings and fan-shaped tails, enabling them to soar in search of food. They use their excellent eyesight to spot prey from high up in the air. They then swoop down to catch the animal. Buteos include the buzzards and the red-tailed hawk.
When a hawk catches its prey, it often carries the animal to a perch. It then holds the prey with its strong feet and legs and tears off pieces of the animal with its beak. Some hawks eat bones, feathers, and fur as well as flesh. Because hawks cannot digest everything they eat, they throw up masses of undigested food called pellets.
Hawks hunt a wide variety of animals, including small mammals, reptiles, fish, insects, and other birds. They also eat animals they find dead. Hawks that prey chiefly on birds have long, thin legs and toes and elongated, sharp, curving talons (claws). These “bird hawks” include many accipiters. Hawks that eat mammals or reptiles have stouter legs, shorter toes, and thicker talons than do bird hawks. Most buteos belong to this group.
Female hawks grow larger and heavier than do males. Hawks measure from 8 to 40 inches (20 to 102 centimeters) in length, with a wingspan of from 19 inches to 71/2 feet (48 centimeters to 2.3 meters). They weigh from 23/4 ounces to 20 pounds (78 grams to 9 kilograms).
Breeding.
Some hawks defend a specific area called a territory. The territory may be a nesting place, a hunting ground, or a temporary winter home. A male or female, or sometimes both mates, may protect the nesting area. Hawks defend territory by attacking or threatening intruders. Such threats can take one or more forms, including raising the feathers on the head or body, calling loudly, and repeatedly flying back and forth. 
Red-tailed hawk
During breeding season, hawks perform courtship displays to attract mates and establish territory. At times during courtship, a hawk may make long aerial climbs or dives. A breeding pair may also fly together and “whirl” in the air with their feet joined. Courting males typically offer prey to females. Certain individual hawks keep the same mate for several breeding seasons.
Hawks nest on cliffs, in trees, or on the ground. Some make a nest by simply scraping away a spot on a ledge. Others build elaborate nests of various plant materials. A few species occupy abandoned nests of other birds. Hawks often use the same nests for many years.
Females lay from one to seven eggs each breeding season. Most species incubate (sit on and warm) their eggs for about 30 to 45 days before they hatch. The female does most of the incubating, while the male provides most of the food. This difference in the roles of the sexes may explain why females grow larger than males.
At hatching, young hawks are covered by a coat of down. The young grow quickly, and eventually both parents must hunt prey for their offspring. Nestlings often compete for food, and many die in the nest. Young hawks stay in the nest for 30 to more than 80 days. However, the offspring of some large species remain dependent on their parents for over a year. Most young die before reaching breeding age. The oldest adult hawks may live more than 40 years.
Migration.
Hawks that inhabit regions with cold winters migrate to warmer areas for the winter. Some individuals migrate alone, while others move by the thousands. Certain species migrate at night and rest during the day. At times, hawks of different sexes or different ages follow different migratory routes. The Swainson’s hawk has one of the longest migrations of any hawk. Each year, it flies from southern Alaska to Argentina. Another impressive migrator, the common buzzard, flies from Siberia in northern Russia to southern Africa. Hawk species that live in warmer regions do not migrate. Loading the player...
Red-tailed hawk
Kinds of hawks.
Goshawks rank as the largest of the true hawks. One common type, the northern goshawk, has gray and white underparts and a whitish streak over its eyes. It lives throughout the northern hemisphere. The white goshawk, a species with white to pale gray coloring, inhabits Australia and the Pacific Islands. The tiny sparrowhawk of tropical Central America and South America ranks as one of the smallest hawks. It typically has a gray and black body, a whitish underside, and a banded gray-and-black tail. The red-tailed hawk of North America has a distinctive call that sounds like “keeeeer.” The Swainson’s hawk lives in western North America. Its whitish wing linings contrast with its dark brown flight feathers. The shikra of Africa and Asia possesses mostly grayish feathers, often with a white and chestnut belly.
Conservation.
Many species of hawks have become threatened with extinction, largely because of the destruction of their natural habitats. Governments and conservation organizations around the world work to protect these species. 
