- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Falconiformes
The term hawk refers to birds of prey in any of three senses:
- In strict use in Europe and Asia, to mean any of the species in the subfamily Accipitrinae in the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter includes goshawks, sparrowhawks , the Sharp-shinned Hawk and others. These are mainly woodland birds with long tails and high visual acuity, hunting by sudden dashes from a concealed perch.
- More generally (especially in North America) to mean small to medium-sized members of the Pandionidae (the Osprey) and the Accipitridae - the family which includes the "true hawks" (Accipiters) as well as eagles, kites, harriers, Buzzard and Old World vultures.
- Loosely, to mean almost any bird of prey outside of the order Strigiformes (owls).
The common names of birds in various parts of the world often use hawk in the second sense. For example, the Osprey or "fish hawk"; or, in North America, the various Buteo species (e.g., the Red-tailed Hawk, B. jamaicensis).
In February 2005, Canadian ornithologist Louis Lefebvre announced a method of measuring avian "IQ" in terms of their innovation in feeding habits. Hawks were named among the most intelligent birds based on his scale.
Hawks are widely reputed to have visual acuity several times that of a normal human being. This is due to the many photoreceptors in the retina (up to 1,000,000 per square mm for Buteo, against 200,000 for humans), an exceptional number of nerves connecting these receptors to the brain, and an indented fovea, which magnifies the central portion of the visual field.
The Red-tailed Hawk
(Buteo jamaicensis) is a medium-sized bird of prey, one of three species colloquially known in the United States as the "chickenhawk." It breeds almost throughout North America from western Alaska and northern Canada to as far south as Panama and the West Indies, and is one of the most common buteos in North America. There are fourteen recognized subspecies, which vary in appearance and range.
It is one of the largest members of the genus Buteo in North America, weighing from 690 to 2000 grams (1.5 to 4.4 pounds) and measuring 4565 cm (18 to 26 in) in length, with a wingspan from 110 to 145 cm (43 to 57 in). The Red-tailed Hawk displays sexual dimorphism in size, as females are 25% larger than males. Red-tailed Hawk plumage can be variable, depending on the subspecies. These color variations are called morphs, and a Red-tailed Hawk may be light, dark, or rufous.
The Red-tailed Hawk is successful in large part because it tolerates a wide range of habitats and altitudes, including deserts, grasslands, coniferous and deciduous forests, tropical rainforests, agricultural fields and urban areas. It lives throughout the North American continent, except in areas of unbroken forest or the high arctic.It is also legally protected in Canada, Mexico and the U.S. by the Migratory Bird Treaty Act of 1918.
The Red-tailed Hawk is a popular bird in falconry, particularly in North America. Approximately 60% of all raptors under 1 year of age taken from the wild for use in American falconry are Red-tailed Hawks. The Red-tailed Hawk also has significance in Native American culture. Its feathers are considered sacred by some tribes, and are used in religious ceremonies.
A male Red-tailed Hawk may weigh from 690 to 1300 grams (1.5 to 2.9 pounds) and measure 4556 cm (18 to 22 in), while a female can weigh between 900 and 2000 grams (2 and 4.4 pounds) and measure 5065 cm (20 to 26 in) in length. As is the case with many raptors the Red-tailed Hawk displays sexual dimorphism in size, as females are 25% larger than males. The wingspan is from 110 to 145 cm (43 to 57 in).
Red-tailed Hawk plumage can be variable.
Though the markings and hue vary, the basic appearance of the Red-tailed Hawk is consistent. The underbelly is lighter than the back and a dark brown band across the belly, formed by vertical streaks in feather patterning, is present in most color variations. The red tail, which gives this species its name, is uniformly brick-red above and pink below. The bill is short and dark, in the hooked shape characteristic of raptors. The cere, the legs, and the feet of the Red-tailed Hawk are all yellow.
The Cooper's Hawk.
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).
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 under parts with reddish bars. They have red eyes and yellow legs. Immatures have brown upperparts and pale under parts 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".
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.
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.
The Broad-winged Hawk
(Buteo platypterus), is a small hawk of the Buteo genus. During the summer they are distributed over most of eastern North America, to as far west as the Alberta province and Texas; they then migrate south to winter in the neotropics from Mexico down to Southern Brazil. Many of the subspecies in the Caribbean are endemic and most do not migrate.
Adult birds range in size from 34 to 45 cm (13 to 18 in), weigh from 265 to 560 g (9.4 oz to 1.2 lbs) and have a wingspan from 81 to 100 cm (32 to 40 in). As in most raptors, females are slightly larger than males. Adults have dark brown upperparts and evenly-spaced black and white bands on the tail. Light morph birds are pale on the under parts and under wing and have thick cinnamon bars across the belly. The light morph is most likely to be confused with the Red-shouldered Hawk, but that species has a longer, more heavily barred tail and the barred wings and solid rufous color of adult Red-shoulders are usually distinctive. Dark morph birds are a darker brown on both upperparts and under parts. They are much less common than the light-colored variant. Dark morph Short-tailed Hawks are similar but are whitish under the tail with a single subterminal band. The wings are relatively short, broad and have a tapered, somewhat pointed appearance unique to this species.
These birds hunt by sitting on a perch and watching for prey, and have been described as "cat-like" while stalking. When prey becomes apparent, they swoop down to the forest floor after it. Rarely, they will also fly in search of prey. The diet is variable, but small mammals, like rodents and shrews, are the most regular prey. More so than other North American Buteo hawks, amphibians, reptiles, insects and other invertebrates are thought to be important prey items. Birds, up to the size of Ruffed Grouse (but usually much smaller), are also sometimes taken.
Broad-winged Hawks are long distance migrants, except for the Caribbean subspecies. They travel in large flocks or "kettles" during migration. During days with favorable winds, enormous kettles of tens of thousands of Broad-wings can be seen along flyways.
The Great Black Hawk
(Buteogallus urubitinga), is a bird of prey in the family Accipitridae, which also includes the eagles, hawks and Old World vultures.
The Great Black Hawk is a resident breeding bird in the tropical New World, from Mexico through Central America to Peru, Trinidad and northern Argentina. It resembles the Common Black Hawk, but is larger with a different call and tail pattern.
This is a mainly coastal bird of forest and open woodland near water. It builds a large stick nest in a tree, and usually lays one dark-blotched whitish egg.
The adult Great Black Hawk is 56 to 64cm long and weighs 1.1 kg. It has very broad wings, and is mainly black. The short tail is white with a broad black tip. The bill is black and the legs and cere are yellow.
The call of Great Black Hawk is a distinctive piping ooo-wheeeeee.
The Great Black Hawk feeds mainly on reptiles, other small vertebrates and large insects, often hunted on foot. This species is often seen soaring above woodlands.
The Harris's Hawk
Harris Hawk, formerly known as the Bay-winged Hawk or Dusky Hawk, is a medium-large bird of prey which breeds from the southwestern USA south to Chile and central Argentina.
Its scientific name is Parabuteo unicinctus. It is the only member of the genus Parabuteo. The name is derived from the Greek para, meaning beside or near, and the Latin buteo, referring to a kind of hawk; uni meaning once; and cinctus meaning girdled, referring to the white band at the base of the tail.
The habitat of Harris's Hawk is sparse woodland and semi-desert, as well as marshes (with some trees) in some parts of its range (Howell and Webb 1995), including mangrove swamps, as in parts of its South American range (Olmos & Silva e Silva, 2003) It nests in a tree and lays 24 eggs, incubated for 28 days to hatching.
It has blackish brown plumage with chestnut forewings (above and below) and thighs. The end of the tail and the rump are white. It has a length of 60 cm and a wingspan of 1.2 m; the average weight is about 900 g (2 pounds). Females are typically 10% bigger than males.
The Hawaiian Hawk
'Io, (Buteo solitarius), is a raptor of the Buteo genus endemic to Hawai'i. Buteos tend to be easily recognized by their bulky bodies relative to their overall length and wingspan. The 'Io is the only hawk that occurs in Hawaii, where they are only known to breed on the Big Island in stands of native `ohi'a lehua trees. The species is protected as Endangered in the United States. However, the IUCN classifies the species as Near Threatened.
The Hawaiian Hawk measures approximately 40 to 46 centimeters (16 to 18 inches) in length. The female is larger than the male. Two color phases exist: a dark phase (dark brown head, breast, and underwings), and a light color phase (dark head, light breast and light underwings). Feet and legs are yellowish in adults and greenish in juveniles.
This solitary hawk remains in and defends its territories year round. They nest from March through September, and usually lay only one egg but sometimes they could lay up to three in their clutch. The female does the majority of sitting during the 38 days of incubation, while the male does the majority of the hunting. After the egg is hatched, the female only allows the male to visit when delivering food to the nest. The chick fledges at seven or eight weeks. Fifty to seventy percent of the nest successfully fledge young.
The 'Io usually hunts from a stationary position, but can also dive on prey from the air. It feeds on rats, small birds, stream animals, crickets, preying mantises, millipedes, centipedes, and occasionally the worm. it will also feed on the Hawaiian Crow, another one of
Hawaii's endangered birds. They are opportunistic predators and are versatile in their feeding habits. They have a shrill and high-pitched call much like their Hawaiian name: "eeeh-oh." They are known to be very noisy during the breeding season. 'Io are strong fliers.
The Hawaiian hawk was a royal symbol in Hawaiian legend, and it is sometimes called 'Iolani, or Exalted Hawk.