Red-tailed hawk

The red-tailed hawk was scientifically described in 1788 by German naturalist Johann Friedrich Gmelin under the name Falco jamaicensis. Gmelin based his description on the "cream-coloured buzzard" described in 1781 by John Latham in his A General Synopsis of Birds, based on a specimen from Jamaica that a friend had sent to him. The red-tailed hawk is one of 28 species in the genus Buteo, which was named by French naturalist Bernard Germain de Lacépède in 1799. Members of the genus Buteo are medium-sized raptors with robust bodies and broad wings. They are known as "buzzards" in Europe, but as "hawks" in North America. The genus name Buteo is derived from the Latin meaning . The specific name jamaicensis refers to the island of Jamaica, which derives from the Taíno word meaning . "Red-tailed hawk" is the official English common name designated by the International Ornithologists' Union. The at least 14 recognized subspecies of Buteo jamaicensis vary in range and coloration: • B. j. jamaicensis, the nominate subspecies, occurs in the northern West Indies. • B. j. alascensis breeds (probably resident) from southeastern coastal Alaska to the Queen Charlotte Islands and Vancouver Island in British Columbia. • B. j. borealis group (eastern red-tailed hawk) • 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. 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, 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. 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. • 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. • 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. It is similar in appearance to B. j. calurus. ==Description==

The red-tailed hawk is dimorphic in size, as females are up to 25% larger than males. Part of this weight is highly seasonally variable and due to clinal variation; male red-tailed hawks may weigh from and females from . Nine studies occurring at migration sites in the United States and two breeding studies, one from the smallest race in Puerto Rico, the other from larger races in Wisconsin, show that males weigh and females weigh on average, about 15% lighter than prior species-wide published weights. The heaviest surveyed weights came from migrants in Cape May, New Jersey, where females averaged , while males averaged in weight. Males can reportedly measure in total length, females measuring long. The wingspan can range from and, in the standard scientific method of measuring wing size, the wing chord is long. The tail measures in length. The middle toe (excluding talon) can range from , with the hallux-claw (the talon of the rear toe, which has evolved to be the largest in accipitrids) measuring from in length. The cere, legs, and feet of the red-tailed hawk are all yellow. Adults are usually easy to identify by their red tails that end in a single black band. Immature birds are more difficult to identify, and their tails are patterned with about six darker bars. Their flight silhouette gives important clues for identification, and at close range, their yellowish irises are characteristic. As the bird attains full maturity over the course of 3–4 years, the iris slowly darkens into a reddish-brown hue. ==Distribution and ecology==

The red-tailed hawk is one of the most common and most widely distributed hawks in the Americas. It breeds from central Alaska, the Yukon, and the Northwest Territories east to southern Quebec and the Maritime Provinces of Canada, and south to Florida, the West Indies, and Central America. The winter range stretches from southern Canada south throughout the remainder of the breeding range. It lives throughout the North American continent, except in areas of unbroken forest or the high Arctic. Adult hawks have few natural predators, although their eggs and chicks are preyed on by a variety of organisms. The red-tailed hawk is widespread in North America, as well as range expansions of many other species of birds. The construction of highways with utility poles alongside treeless medians provided perfect habitat for perch-hunting. Unlike some other raptors, the red-tailed hawk is seemingly unfazed by considerable human activity and can nest and live in close proximity to large numbers of humans. One famous urban red-tailed hawk, known as "Pale Male", became the subject of a nonfiction book, Red-Tails in Love: A Wildlife Drama in Central Park, and is the first known red-tail in decades to successfully nest and raise young in the crowded New York City borough of Manhattan. Since red-tailed hawks are relatively specialized feeders, they harbor fewer helminth parasitic worms than species like the broad-winged hawk, which have a wider diet. Hawks in urban areas are threatened by the use of rat traps and poisoned bait to kill rodents. This generally consists of warfarin cookies, which induce internal bleeding in rats and mice, and a hawk that ingests rodents that have consumed rat poison can itself be affected. ==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. Vocalization The cry of the red-tailed hawk is a two- to three-second, hoarse, rasping scream, described as kree-eee-ar, Young hawks may utter a wailing klee-uk food cry when parents leave the nest. The fierce, screaming cry of the red-tailed hawk is frequently used as a generic raptor sound effect in television shows and other media, even if the bird featured is not a red-tailed hawk. Diet The red-tailed hawk preys on small mammals such as rodents and lagomorphs, but also opportunistically consumes birds, fish, reptiles, and amphibians. Prey varies with regional and seasonal availability, but usually centers on rodents, comprising up to 85% of a hawk's diet. Additional prey (listed in descending likelihood of predation) include lagomorphs, shrews, bats, pigeons, quail, corvids, waterfowl, other raptors, reptiles, fish, crustaceans, insects and earthworms. Hawks have been observed following American badgers to capture prey they flush, and the two are considered potential competitors. Competition over carcasses may occur with American crows, and several crows working together can displace a hawk. Larger raptors, such as eagles and ferruginous hawks, may steal hawk kills. The same nesting territory may be defended by the pair for years. During courtship, the male and female fly in wide circles while uttering shrill cries. The male performs aerial displays, diving steeply, and then climbing again. After repeating this display several times, he sometimes grasps her talons briefly with his own. Courtship flights can last 10 minutes or more. Copulation often follows courtship flight sequences, although copulation also frequently occurs in the absence of courtship flights. 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 prenesting courtship in late winter or early spring, can occur numerous times each day. In the same period, the pair constructs a stick nest in a large tree off the ground or on a cliff ledge or higher above the ground, or may nest on man-made structures. The nest is generally in diameter and can be up to tall. The nest is constructed of twigs 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. A clutch of one to five eggs is laid in spring, with an egg roughly every second day. They are incubated by both parents. The altricial nestlings emerge from the eggs over 2 to 4 days. The female broods them while the male provides most of the food to the female. The female feeds the young, tearing it into manageable pieces for them. After 42 to 46 days, the young start to leave the nest. Fledging, including learning to fly and hunt, takes some 10 weeks. About 6 to 7 weeks after fledging, the young begin to capture their own prey. Autumn hawk watches in Ontario, Quebec, and the northern United States have recorded 4,500–8,900 red-tailed hawks migrating through, with records of up to 15,000 in a season at Hawk Ridge in Duluth, Minnesota. Unlike some other Buteo species, such as Swainson's hawks and broad-winged hawks, red-tailed hawks do not usually migrate in groups, instead passing by one-by-one, and only migrate on days when winds are favorable. Spring northward movements may commence as early as late February, with peak numbers usually occurring in late March and early April. Seasonal counts may include up to 19,000 red-tails in spring at Derby Hill hawk watch, in Oswego, New York; sometimes, more than 5,000 have been recorded in a day there. ==Relationship with humans==

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 and where red-tailed hawks are both widely available and allowed to novice falconers. Red-tailed hawks are highly tameable and trainable, with a more social disposition than all other falcons or hawks other than Harris's hawk. They are also long-lived and highly disease-resistant, allowing a falconer to maintain a red-tailed hawk as a hunting companion for many years. Fewer than 5,000 falconers are in the United States, so despite their popularity, any effect on the red-tailed hawk population, estimated to be about one million in the United States, is negligible. Not being as swift as falcons or accipiters, red-tailed hawks are not the most effective of bird hawks and are usually used against ground game such as rabbits and squirrels. Some individuals, though, may learn to ambush birds on the ground with a swift surprise approach and capture them before they can accelerate to full speed and escape. Some have even learned to use a falcon-like diving stoop to capture challenging game such as pheasants. In the course of a typical 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. Feathers and Native American use The feathers and other parts of the red-tailed hawk are considered sacred to many American indigenous people, and like the feathers of the bald eagle and golden eagle, are sometimes used in religious ceremonies and found adorning the regalia of many Native Americans in the United States; these parts, most especially their distinctive tail feathers, are a popular item in the Native American community. As with the other two species, the feathers and parts of the red-tailed hawk are regulated by the eagle feather law, which governs the possession of feathers and parts of migratory birds. ==References==