| Harlan's hawk | |
|---|---|
 | |
| A Harlan's hawk illustrates its silvery-white tail. | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Accipitriformes |
| Family: | Accipitridae |
| Genus: | Buteo |
| Species: | |
| Subspecies: | B. j. harlani |
| Trinomial name | |
| Buteo jamaicensis harlani (Audubon, 1830) | |
Harlan's hawk or Harlan's red-tailed hawk (Buteo jamaicensis harlani) [1] is a subspecies of the red-tailed hawk.
While similar in linear dimensions to the western red-tailed hawk (B. j. calurus), this race is sometimes described as slighter and lighter. [2] On the contrary, though, they are highly sexually dimorphic in size (the most dimorphic of any in the United States) and mature females are sometimes more massive than almost any female B. j. calurus. [3] However, B. j. calurus tends to have a much longer tarsus than Harlan's hawks do, as expected due to the latter's habitation to cold environments almost year around. [4] The wing chord of males can range from 365 to 390 mm (14.4 to 15.4 in), averaging 381 mm (15.0 in), and, in females, it ranges from 390 to 430 mm (15 to 17 in), averaging 408.7 mm (16.09 in). Males and females average 211 and 225.3 mm (8.31 and 8.87 in) in tail length, 79.8 and 87 mm (3.14 and 3.43 in) in tarsal length and 24.7 and 27 mm (0.97 and 1.06 in) in culmen length. [5] [6] [7] A wintering female in eastern Kansas weighed 1,629 g (3.591 lb). [8]
The historic taxonomic status of Harlan's hawk has been quite erratic; sometimes, it has been classified as its own species, B. harlani to the opposite extreme that R. S. Palmer (1988) classified as it (perhaps improbably) as a mere western color morph. Most modern authorities recognize Harlan's hawk as a valid subspecies. [3] [4] [9] Harlan's hawk is markedly different from all other red tails and can be identified nearly 100% of the time by an experienced hawk watcher. [4] [9] Throughout the morphs of this subspecies, the plumage is predominantly blackish, lacking any warmer or brownish tones (save the tail). Harlan's hawks usually have faint streaks on the sides of their head and about their chest with a bit of gray mottling or speckling on the scapulars. Apart from a variably white-streaked throat, their underparts are usually mostly black with variable white streaking and barring on the thighs or crissum. There are up to four main variations from the typical one described above: extreme dark morph (where even the throat is black and no pale streaking is present), dark morph (with barring still present from the tarsus to the underside), rare pale morph (with few blackish blobs on the belly and generally a whiter head) and perhaps even rarer types, the base color of which is grayish. Unlike most red-tailed hawks, immatures are generally similar enough to adults that it can be difficult to distinguish them. On average, immatures have more extensive pale streaking above and mottling below, but much individual variation has been recorded. The typical tail of a Harlan's hawk is white with a thick black subterminal band but individuals may vary considerably and the tail may be reddish, dusky, whitish or gray and can be longitudinally streaked, mottled or barred. [5] [4] [9]
It breeds from central Alaska to northwestern Canada, with the largest number of birds breeding in the Yukon or western Alaska, reaching their southern limit in north-central British Columbia. Harlan's hawk is restricted as a breeder to pure taiga habitat. Harlan's hawk winters from Nebraska and Kansas to Texas and northern Louisiana, with a rare bird found as far east as Tennessee. [6] [10] [11] [12]
The common buzzard is a medium-to-large bird of prey which has a large range. It is a member of the genus Buteo in the family Accipitridae. The species lives in most of Europe and extends its breeding range across much of the Palearctic as far as northwestern China, far western Siberia and northwestern Mongolia. Over much of its range, it is a year-round resident. However, buzzards from the colder parts of the Northern Hemisphere as well as those that breed in the eastern part of their range typically migrate south for the northern winter, many journeying as far as South Africa.
The rough-legged buzzard (Europe) or rough-legged hawk is a medium-large bird of prey. It is found in Arctic and Subarctic regions of North America, Europe, and Russia during the breeding season and migrates south for the winter. It was traditionally also known as the rough-legged falcon in such works as John James Audubon's The Birds of America.
The red-tailed hawk is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members within the genus of Buteo in North America or worldwide. The red-tailed hawk is one of three species colloquially known in the United States as the "chickenhawk", though it rarely preys on standard-sized chickens. The bird is sometimes also referred to as the red-tail for short, when the meaning is clear in context. Red-tailed hawks can acclimate to all the biomes within their range, occurring on the edges of non-ideal habitats such as dense forests and sandy deserts. The red-tailed hawk occupies a wide range of habitats and altitudes, including deserts, grasslands, coniferous and deciduous forests, agricultural fields, and urban areas. Its latitudinal limits fall around the tree line in the subarctic and it is absent from the high Arctic. Generally it favors varied habitats with open woodland, woodland edge and open terrain. It is legally protected in Canada, Mexico, and the United States by the Migratory Bird Treaty Act.
The broad-winged hawk is a medium-sized hawk of the genus Buteo. During the summer, some subspecies are distributed over eastern North America, as far west as British Columbia and Texas; they then migrate south to winter in the Neotropics from Mexico south to southern Brazil. Other subspecies are all-year residents on Caribbean islands. As in most raptors, females are slightly larger than males. Broad-winged hawks' wings are relatively short and broad with a tapered, somewhat pointed appearance. The two types of coloration are a dark morph with fewer white areas and a light morph that is more pale overall. Although the broad-winged hawk's numbers are relatively stable, populations are declining in some parts of its breeding range because of forest fragmentation.
Harris's hawk, formerly known as the bay-winged hawk, dusky hawk, and sometimes a wolf hawk, and known in Latin America as peuco, is a medium-large bird of prey that breeds from the southwestern United States south to Chile, central Argentina, and Brazil. This bird is sometimes reported to be at large in Western Europe, especially Britain, but it is a popular species in falconry and these records almost invariably all refer to escapes from captivity.
The eastern red-tailed hawk is a subspecies of the red-tailed hawk that breeds from southeast Canada and Maine south through Texas and east to northern Florida.
The western red-tailed hawk is a subspecies of the red-tailed hawk.
The southwestern red-tailed hawk is a subspecies of red-tailed hawk that breeds from northern Chihuahua to southern Texas. It winters in Arizona, New Mexico and southern Louisiana. This seems to be a particularly large subspecies, although its size is not drastically different from the western red-tailed hawk, and, going on average wing size and tarsal length, this appears to be the largest race of red-tailed hawk. The wing chord of males can range from 385 to 402 mm, averaging 393.3 mm (15.48 in), and, in females, it ranges from 425 to 436 mm, averaging 430.7 mm (16.96 in). Additionally, males and females average 210.9 and 223.8 mm in tail length, 88 and 93 mm in tarsal length and 26.3 and 27.5 mm in culmen length. Hybridization seems to occur in eastern Texas with the eastern red-tailed hawk, broadly to the west with B. j. calurus and, possibly, in Nuevo León and Chihuahua with the Mexican Highlands red-tailed hawk. This race combines the darker back of B. j. calurus with the paler underside of B. j. borealis, with the belly band either entirely absent or only manifesting in light streaking. The tail is variable but relatively pale, with some individuals showing almost no dark subterminal band, others having quite a broad subterminal band and some showing extensively barring on top like darker morphs of B. j. calurus.
Krider's hawk or Krider's red-tailed hawk is a subspecies or color morph of red-tailed hawk. Authorities vary in their treatment of the taxon. It was named after John Krider, the gunsmith from Philadelphia who collected the type specimen, which is preserved in the collection of the Academy of Natural Sciences of Drexel University.
The gray hawk or Mexican goshawk is a smallish raptor found in open country and forest edges. It is sometimes placed in the genus Asturina as Asturina plagiata. The species was split by the American Ornithological Society (AOU) from the gray-lined hawk. The gray hawk is found from Costa Rica north into the southwestern United States.
Swainson's hawk is a large bird species in the Accipitriformes order. This species was named after William Swainson, a British naturalist. It is colloquially known as the grasshopper hawk or locust hawk, as it is very fond of Acrididae and will voraciously eat these insects whenever they are available.
The Jamaican red-tailed hawk is the nominate subspecies of the red-tailed hawk, a bird of prey of North America. The subspecies B. j. jamaicensis occurs in the northern West Indies, including Jamaica, Hispaniola, Puerto Rico and the Lesser Antilles, but not the Bahamas or Cuba, where it is replaced by the Cuban red-tailed hawk. El Yunque National Forest, Puerto Rico, holds some of the highest known density of Jamaican red-tailed hawks. The bird is referred to as a guaraguao in the Dominican Republic and Puerto Rico.
The Alaska red-tailed hawk is a subspecies of red-tailed hawk that breeds from southeastern coastal Alaska to the Queen Charlotte Islands and Vancouver Island in British Columbia. Despite its northerly distribution, this is the second smallest of the red-tailed hawks. Only the Jamaican red-tailed hawk is smaller.
The Central American red-tailed hawk is a subspecies of red-tailed hawk resident from Nicaragua to Panama. This subspecies is relatively small. The wing chord of males can range from 368 to 391 mm, averaging 372.7 mm (14.67 in), and, in females, it ranges from 393 to 427 mm, averaging 401.9 mm (15.82 in). Additionally, males and females average 213.2 and 230 mm in tail length, 88.6 and 86.9 mm in tarsal length and 26 and 26.7 mm in culmen length. This race may average around 900 g (2.0 lb). This subspecies is arguably the most handsomely colored in typical adult plumage. This subspecies is dark brown above and heavily pigmented dorsally, the white of the breast contrasting with a deep rufous abdominal band which contains black streaks and spots. Meanwhile, the flanks, wing linings and sides are an unbarred deep rufous. In some birds, the rich rufous color continues to the underside. The chest is much less heavily streaked than in northern migrants western red-tailed hawk to Central America. Unlike other Central American races of red-tailed hawk, there seems to be no dark morph in this subspecies.
The Tres Marias red-tailed hawk is a relatively small subspecies of red-tailed hawk endemic to Islas Marías, an island some 100 km (62 mi) off the coast of Mexico. Unlike some other island races, the validity of this race has rarely been called into question. The wing chord of males can range from 368 to 370 mm, averaging 369.3 mm (14.54 in), and, in females, it ranges from 395 to 400 mm, averaging 397.4 mm (15.65 in). Males and females average 228.9 and 235.5 mm in tail length, 85.9 and 88.3 mm in tarsal length and 27.4 and 29.2 mm in culmen length. This race is similar to the western red-tailed hawk but, beyond being noticeably smaller, is duskier and duller hued overall and has a more cinnamon wash below, with heavily dark barred thighs.
The Mexican Highlands red-tailed hawk is a subspecies of red-tailed hawk endemic to the Mexican Highlands. Not all authorities recognize this race, however, in recent years, most list it as valid. Like other Neotropical races, this one is relatively small. wing chord averages 378.9 mm (14.92 in) in males and 401.1 mm (15.79 in) in females. Males and females average 215 and 230.4 mm in tail length, 89.1 and 88 mm in tarsal length and 26.3 and 26.8 mm in culmen length. Apparently, this race is similar to B. j. kemsiesi to the south but unlike that race it has rufous barring that extends to the flanks and belly. Apparently, some dark morphs have occurred. One other unique feature is its massive feet, with a toe length nearly 10% longer than the western red-tailed hawk despite its otherwise small body size. The evolutionary reason for these relatively large feet is unknown.
The red-tailed hawk kemsiesi is a dark subspecies of red-tailed hawk resident from Chiapas, Mexico, to Nicaragua. The wing chord of males can range from 357 to 382 mm, averaging 376 mm (14.8 in), and, in females, it ranges from 362 to 402 mm, averaging 398.2 mm (15.68 in). Males and females average 212.5 and 231 mm in tail length, 87.8 and 87.1 mm in tarsal length and 26.1 and 26.4 mm in culmen length. This race is similar to the southwestern red-tailed hawk but markedly smaller, with its thighs barred with rufous. The dark wing marking may not be distinct in paler birds. A dark morph, similar to the western red-tailed hawk, is known to occur in this race.
The Socorro red-tailed hawk is a subspecies of red-tailed hawk endemic to Socorro Island, 600 kilometres (370 mi) off the west coast of Mexico. The wing chord of males can range from 368 to 385 mm, averaging 378.4 mm (14.90 in), and, in females, it ranges from 385 to 415 mm, averaging 412.8 mm (16.25 in). Males and females average 214.1 and 230.4 mm in tail length, 84.9 and 89.1 mm in tarsal length and 24.9 and 28.6 mm in culmen length. One female was found to have weighed 1,260 g (2.78 lb). This race, which is physically fairly similar to the western red-tailed hawk, is not recognized by some authorities because it has a breeding population of perhaps fewer than 20 birds. There are some differences from B. j. calurus, such as their larger, more robust feet and much greater sexual dimorphism, which is the most pronounced of any race linearly, averaging 10.42% when all standard measurements are considered. Furthermore, Socorro hawks tend to average more melantic in overall color, being a duller, darker brown than mainland birds.
The Cuban red-tailed hawk is a subspecies of red-tailed hawk native to the Bahamas, Florida, and Cuba.
The Florida red-tailed hawk is a subspecies of red-tailed hawk. It occurs year-round in peninsular Florida north as far as Tampa Bay and the Kissimmee Prairie and south down to the Florida Keys. This subspecies is very large, only the southwestern red-tailed hawk averages larger in overall dimensions. Although a non-migratory subspecies, its wings are notably longer than those of the eastern red-tailed hawk and S. b. umbrinus may be conspicuously larger than the relatively small southern S. b. borealis that they overlap with. The wing chord of males can range from 396 to 400 mm, averaging 398.8 mm (15.70 in), and, in females, it ranges from 373 to 432 mm, averaging 408.9 mm (16.10 in). Males and females average 225 and 234 mm in tail length, 91.1 and 88.9 mm in tarsal length and 27.2 and 30 mm in culmen length. Compared to B. j. borealis which it replaces, it has a darker back, more similar to the dark brown of the western red-tailed hawk. Adults tend to have chestnut to rufous side patches, multiple tail bars and no barring on the "trousers". A very rare dark morph has been reported.
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