Red-tailed hawk


The red-tailed hawk is a bird of prey and one of the most common hawks in North America. In the United States, it is one of three species colloquially known as the "chickenhawk". The red-tailed hawk breeds throughout most of the continent, from western Alaska and northern Canada to as far south as Panama and the West Indies. The red-tailed hawk occupies a wide range of habitats and altitudes including deserts, grasslands, coniferous and deciduous forests, agricultural fields and urban areas. It is absent in areas of unbroken forest and in the high arctic. It is legally protected in Canada, Mexico and the United States by the Migratory Bird Treaty.
The red-tailed hawk is one of the largest members of the genus Buteo in North America, typically weighing from and measuring in length, with a wingspan from. Females are about 25% heavier than males. It has a stocky body with broad wings, and can be distinguished from other North American hawks by the eponymous tail, which is uniformly brick-red above and light buff-orange below. The species feeds on a wide range of small animals such as rodents, birds, and reptiles. Pairs stay together for life, taking a new mate only when the original mate dies. The pair constructs a stick nest in a high tree, in which a clutch of one to three eggs is laid.
The 14 recognized subspecies vary in appearance and range. The subspecies Harlan's hawk is sometimes considered a separate species. Because they are so common and easily trained as capable hunters, the majority of hawks captured for falconry in the United States are red-tailed hawks. The feathers and other parts of the red-tailed hawk are considered sacred to many American indigenous people.

Taxonomy

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 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 būteō meaning. The specific name jamaicensis refers to the island of Jamaica, which derives from the Taíno word Xaymaca meaning. "Red-tailed hawk" is the official English common name designated by the International Ornithologists' Union. In the United States, the red-tailed hawk is one of three species colloquially known as the "chickenhawk," though it rarely preys on standard-sized chickens.
There are at least 14 recognized subspecies of Buteo jamaicensis, which vary in range and in coloration: The subspecies Harlan's hawk is sometimes considered a separate species.
  • B. j. jamaicensis, the nominate subspecies, occurs in the northern West Indies.
  • B. j. alascensis breeds from southeastern coastal Alaska to the Queen Charlotte Islands and Vancouver Island in British Columbia.
  • B. j. borealis group 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.
  • 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. Paler individuals of northern Mexico may lack the dark wing marking.
  • 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 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. 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 calurus.

    Description

The red-tailed hawk is sexually dimorphic in size, as females are up to 25% larger than males. As is typical in large raptors, frequently reported mean body mass for red-tailed hawks is somewhat higher than expansive research reveals. Part of this weight is highly seasonally variable and due to clinal variation, male red-tailed hawks may weigh from and females between. However, research 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 a mean of and females weigh a mean of, about 15% lighter than prior species-wide published weights. The heaviest surveyed weights came from migrants in Cape May, New Jersey, where females weighed a mean of, males a mean of. The lightest were from the breeding population in forest openings of Puerto Rico, where the females and males weighed an average of and, respectively, also the highest size sexual dimorphism in the species. Size variation in body mass reveals that the red-tailed hawks typically vary only a modest amount; racial variation in average weights of great horned owls show that mean body mass is nearly twice as variable as that of the hawk. 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 can range from, with the hallux-claw measuring from in length.
Red-tailed hawk plumage can be variable, depending on the subspecies and the region. These color variations are morphs, and are not related to molting. The western North American population, B. j. calurus, is the most variable subspecies and has three color morphs: light, dark, and intermediate or rufus. The dark and intermediate morphs constitute 10–20% of the population.
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 and often heavier than other Buteos of similar length. 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. 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. They have relatively short, broad tails and thick, chunky wings. The cere, the legs, and the feet of the red-tailed hawk are all yellow.
Adults are usually easy to identify by their red tail that ends in a single black band. Immature birds are more difficult to identify, and their tail is 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.
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, coniferous and deciduous woodlands, tropical rainforests, agricultural fields and urban areas. It is second only to the peregrine falcon in the use of diverse habitats in North America. 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, 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 increase in trees throughout the Great Plains during the past century due to fire suppression and tree planting facilitated the western range expansion of the red-tailed hawk 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 are seemingly unfazed by considerable human activity and can nest and live in close proximity to large numbers of humans. Thus, the species can also be found in cities, where common prey such as rock pigeons and brown rats may support their populations. One famous urban red-tailed hawk, known as "Pale Male", became the subject of a non-fiction 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 who have consumed rat poison can itself be affected.