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| Red-tailed Hawk | |
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| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Falconiformes (or Accipitriformes, q.v.) |
| Family: | Accipitridae |
| Genus: | Buteo |
| Species: | B. jamaicensis |
| Binomial name | |
| Buteo jamaicensis (Gmelin, 1788) |
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| Synonyms | |
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Buteo borealis Buteo broealis (lapsus) |
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The Harlan's Hawk (B. j. harlani), often considered a separate species, is treated below in the Taxonomy section.
The Red-tailed Hawk occupies 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 legally protected in Canada, Mexico and the United States by the Migratory Bird Treaty Act.
Because they are so common and easily trained as capable hunters, the majority of hawks captured for falconry in the United States are Red-tails. Falconers are permitted to take only passage hawks (which have left the nest, are on their own, but are less than a year old) so as to not affect the breeding population. Adults, which may be breeding or rearing chicks, may not be taken for falconry purposes and it is illegal to do so. Passage red-tailed hawks are also preferred by falconers because these younger birds have not yet developed adult behaviors, which will make training substantially more challenging.
Contents
Description
A male Red-Tailed Hawk may weigh from 690 to 1,300 g (24 to 46 oz), with a mean weight of 1,030 g (36 oz), and measure 45–60 cm (18–24 in). A female can weigh between 900 and 2,000 g (32 and 71 oz), averaging 1,220 g (43 oz), and measure 48 to 65 cm (19 to 26 in) long. The wingspan can range from 105 to 141 cm (41 to 56 in) and, in the standard scientific method of measuring wing size, the wing bone is 33–44 cm (13–17 in) long. The tail measures 19–25 cm (7.5–9.8 in) in length.[4][5][6] The exposed culmen was reported to average 2.5–2.7 cm (0.98–1.1 in) and the tarsus averaged 8.6–9 cm (3.4–3.5 in).[7] As is the case with many raptors the Red-tailed Hawk displays sexual dimorphism in size, as females are up to 25% larger than males.[8]
Though the markings and hue vary across the subspecies, the basic appearance of the Red-tailed Hawk is consistent. Overall, this species is blocky and broad in shape, often appearing (and being) heavier than other Buteos of similar length.[4] A whitish underbelly with a dark brown band across the belly, formed by horizontal streaks in feather patterning, is present in most color variations. Especially in younger birds, the underside may be otherwise covered with dark brown spotting. The red tail, which gives this species its name, is uniformly brick-red above and light buff-orange below.[4][10] The bill is short and dark, in the hooked shape characteristic of raptors, and the head can sometimes appear small in size against the thick body frame.[4] They have a relatively short, broad tails and thick, chunky wings.[10] The cere, the legs, and the feet of the Red-tailed Hawk are all yellow.[8]
Immature birds can be readily identified at close range by their yellowish irises. As the bird attains full maturity over the course of 3–4 years, the iris slowly darkens into a reddish-brown hue. In both the light and dark morphs, the tail of the immature Red-tailed Hawk are patterned with numerous darker bars.[10]
Taxonomy
There are at least 14 recognized subspecies of Buteo jamaicensis, which vary in range and in coloration:
- B. j. jamaicensis, the nominate subspecies, occurs in the northern West Indies, including Jamaica, Hispaniola, Puerto Rico and the Lesser Antilles but not the Bahamas or Cuba. El Yunque National Forest, Puerto Rico holds the highest known density of Red-tailed Hawks anywhere.[12]
- B. j. alascensis breeds (probably resident) from southeastern coastal Alaska to the Queen Charlotte Islands and Vancouver Island in British Columbia.[13]
- B. j. borealis breeds from southeast Canada and Maine south through eastern Texas and east to northern Florida. It winters from southern Ontario east to southern Maine and south to the Gulf coast and Florida.[13]
- B. j. calurus breeds from central interior Alaska, through western Canada south to Baja California. It winters from southwestern British Columbia southwest to Guatemala and northern Nicaragua.[13] Paler individuals of northern Mexico may lack the dark wing marking.[14]
- B. j. costaricensis is resident from Nicaragua to Panama. This subspecies is dark brown above with cinnamon flanks, wing linings and sides, and some birds have rufous underparts. The chest is much less heavily streaked than in northern migrants (B. j. calurus) to Central America.
- B. j. fuertesi breeds from northern Chihuahua to southern Texas. It winters in Arizona, New Mexico, and southern Louisiana.[13] The belly is unstreaked or only lightly streaked, and the tail is pale.
- B. j. fumosus Islas Marías, Mexico
- B. j. hadropus Mexican Highlands
- B. j. harlani, Harlan's Hawk, is markedly different from all other Red-tails. In both color morphs, the plumage is blackish and white, lacking warm tones (save the tail). The tail may be reddish, dusky, whitish, or gray and can be longitudinally streaked, mottled, or barred. Shorter primaries result in wingtips that don't reach the tail in perched birds. It breeds in Alaska and northwestern Canada and winters from Nebraska and Kansas to Texas and northern Louisiana.[13] This population may well be a separate species.
- B. j. kemsiesi is a dark subspecies resident from Chiapas to Nicaragua. The dark wing marking may not be distinct in paler birds.[14]
- B. j. kriderii is paler than other Red-tails, especially on the head; the tail may be pinkish or white. In the breeding season, it occurs from southern Alberta, southern Saskatchewan, southern Manitoba, and extreme western Ontario south to south-central Montana, Wyoming, western Nebraska, and western Minnesota. In winter, it occurs from South Dakota and southern Minnesota south to Arizona, New Mexico, Texas and Louisiana.[13]
- B. j. socorroensis Socorro Island, Mexico
- B. j. solitudinus Bahamas and Cuba
- B. j. umbrinus occurs year-round in peninsular Florida north to Tampa Bay and the Kissimmee Prairie.[13] It is similar in appearance to calurus
Distribution and habitat
Its preferred habitat is mixed forest and field, with high bluffs or trees that may be used as perch sites. It occupies a wide range of habitats and altitudes, including deserts, grasslands, coastal regions, mountains, foothills of mountains coniferous and deciduous woodlands, tropical rainforests, agricultural fields and urban areas.[1] It is second only to the Peregrine Falcon in the use of diverse habitats in North America.[15] It lives throughout the North American continent, except in areas of unbroken forest or the high Arctic.[9]
The Red-tailed Hawk is widespread in North America,[15] partially due to historic settlement patterns, which have benefited it. The clearing of forests in the Northeast created hunting areas, while the preservation of woodlots left the species with viable nest sites. The planting of trees in the west allowed the Red-tailed Hawk to expand its range by creating nest sites where there had been none. The construction of highways with utility poles alongside treeless medians provided perfect habitat for perch-hunting. Unlike some other raptors, the Red-tailed Hawk are seemingly unfazed by considerable human activity and can nest and live in close proximity to large numbers of humans.[4] Thus, the species can also be found in cities, where common prey such as rock pigeons and brown rats may support their populations.[16] One urban Red-tailed Hawk, known as "Pale Male", became famous for being the first Red-tail in decades to successfully nest and raise young in the crowded New York City borough of Manhattan.[17]
Behavior
Flight
In flight, this hawk soars with wings often in a slight dihedral, flapping as little as possible to conserve energy. Active flight is slow and deliberate, with deep wing beats. In wind, it occasionally hovers on beating wings and remains stationary above the ground.[9] When soaring or flapping its wings, it typically travels from 20 to 40 mph (64 km/h), but when diving may exceed 120 mph (190 km/h).[18]Vocalization
Diet
The Red-tailed Hawk is carnivorous, and an opportunistic feeder. Its diet is mainly small mammals, but it also includes birds and reptiles. Prey varies with regional and seasonal availability, but usually centers on rodents, comprising up to 85% of a hawk's diet.[8] Most commonly reported prey types include mice, including both native Peromyscus species and house mice, gophers, voles, chipmunks, ground squirrels and tree squirrels.[22][23] Additional prey (listed by descending likelihood of predation) include lagomorphs, shrews, bats, pigeons, quail, corvids, waterfowl, other raptors, reptiles, fish, crustaceans, insects and earthworms.[4] Where found in Caribbean islands, Red-tailed Hawks prey mostly on reptiles such as snakes and lizards, since these are perhaps the most predominant native land animals of that region.[4] Prey specimens can range to as small a size as beetles and worms. However, they can also prey on marmots, White-tailed Jackrabbits, small domestic dogs, domestic cats, or female Wild Turkey, all of which are easily double the weight of most Red-tails.[4] Although they prefer to feed on fresh prey they've killed themselves, these hawks are not above occasionally consuming carrion. During winter in captivity, an average Red-tail will eat about 135 g (4.8 oz) daily.[20]The Red-tailed Hawk commonly employ one of two hunting technique. Often, they scan for prey activity from an elevated perch site, swooping down from the perch to seize the prey. They also watch for prey while flying, either capturing a bird in flight or pursuing prey on the ground until they can pin them down in their talons.[4] Red-tailed Hawks, like some other raptors, have been observed to hunt in pairs. This may consist of stalking opposites sides of a tree, in order to surround a tree squirrel and almost inevitably drive the rodent to be captured by one after being flushed by the other hawk.[24] They are opportunistically attracted to conspicuous meals, such as displaying male Red-winged Blackbirds.[8]
Reproduction
In copulation, the female, when perched, tilts forward, allowing the male to land with his feet lodged on her horizontal back. The female twists and moves her tail feathers to one side, while the mounted male twists his cloacal opening around the female's cloaca. Copulation lasts 5 to 10 seconds and during pre-nesting courtship in late winter or early spring can occur numerous times each day.[30]
In the same period, the pair constructs a stick nest in a large tree 4 to 21 m (13 to 69 ft) off the ground or on a cliff ledge 35 m (115 ft) or higher above the ground, or may nest on man-made structures. The nest is generally 71 to 97 cm (28 to 38 in) in diameter and can be up to 90 cm (3.0 ft) tall. The nest is constructed of twigs, and lined with bark, pine needles, corn cobs, husks, stalks, aspen catkins, or other plant lining matter.
Great Horned Owls compete with the Red-tailed Hawk for nest sites. Each species has been known to kill the young and destroy the eggs of the other, but in general, both species nest in adjacent or confluent territories without conflict. Great Horned Owls are incapable of constructing nests and typically expropriate existing Red-tail nests. Great Horned Owls begin nesting behaviors much earlier than Red-tails, often as early as December. Red-tails are therefore adapted to constructing new nests when a previous year's nest has been overtaken by owls or otherwise lost. New nests are typically within a kilometer or less of the previous nest. Often, a new nest is only a few hundred meters or less from a previous one. Being a large predator, most predation of these hawks occurs with eggs and nestlings, which are taken by owls, corvids and raccoons.[31]
Relationship with humans
The non-fiction book Red-Tails in Love: A Wildlife Drama in Central Park by Marie Winn is about Pale Male, a famous urban Red-tailed Hawk in New York.[32]Use in falconry
The Red-tailed Hawk is a popular bird in falconry, particularly in the United States where the sport of falconry is tightly regulated at the federal and state levels. There are fewer than 5,000 falconers in the United States, therefore any effect on the Red-tailed Hawk population, estimated to be about one million in the United States, is statistically insignificant.[33]In the course of a hunt, a falconer using a Red-tailed Hawk most commonly releases the hawk and allows it to perch in a tree or other high vantage point. The falconer, who may be aided by a dog, then attempts to flush prey by stirring up ground cover. A well-trained Red-tailed Hawk will follow the falconer and dog, realizing that their activities produce opportunities to catch game. Once a raptor catches game, it does not bring it back to the falconer. Instead, the falconer must locate the bird and its captured prey, "make in", (carefully approach) and trade the bird its kill in exchange for a piece of offered meat.[34]
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