Harlan's hawk or Harlan's red-tailed hawk (''Buteo jamaicensis harlani'') Website based on / supplement to book, is a subspecies of the

red-tailed hawk The red-tailed hawk (''Buteo jamaicensis'') 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 of ...

Description

While similar in linear dimensions to the western red-tailed hawk (''B. j. calurus''), this race is sometimes described as slighter and lighter.Dunne, P.; Sibley, D. & Sutton, C. (1988). ''Hawks in Flight: The Flight Identification of North American Migrant Raptors''. Houghton Mifflin Harcourt. On the contrary, though, they are highly

sexually dimorphic Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

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''.Palmer, R. S. ed. (1988). ''Handbook of North American Birds''. Volume 5 Diurnal Raptors (Part 2). 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.Clark, W. S. (2014)
"Harlan's Hawk differs from Red-Tailed Hawk"
. Global Raptor Information Network. The wing chord of males can range from , averaging , and, in females, it ranges from , averaging . Males and females average in tail length, in tarsal length and in culmen length.Ridgway, R. & Friedmann, H. (1919). ''The Birds of North and Middle America: A Descriptive Catalogue of the Higher Groups, Genera, Species, and Subspecies of Birds Known to Occur in North America, from the Arctic Lands to the Isthmus of Panama, the West Indies and Other Islands of the Caribbean Sea, and the Galapagos Archipelago''. Vol. 50, No. 8. Govt. Print. A wintering female in eastern

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

weighed . 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. 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. 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.

Distribution

It breeds from central

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

to northwestern Canada, with the largest number of birds breeding in the

Yukon Yukon () is a Provinces and territories of Canada, territory of Canada, bordering British Columbia to the south, the Northwest Territories to the east, the Beaufort Sea to the north, and the U.S. state of Alaska to the west. It is Canada’s we ...

or western

, reaching their southern limit in north-central

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

. Harlan's hawk is restricted as a breeder to pure

taiga Taiga or tayga ( ; , ), also known as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga, or boreal forest, is the world's largest land biome. In North A ...

habitat. Harlan's hawk winters from

Nebraska Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...

and

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

and northern

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

, with a rare bird found as far east as

Tennessee Tennessee (, ), officially the State of Tennessee, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Kentucky to the north, Virginia to the northeast, North Carolina t ...

.Preston, C. R. & Beane, R. D. (2009). "Red-tailed Hawk (''Buteo jamaicensis'')". ''The Birds of North America''. .Johnsgard, P. A. (1990). ''Hawks, Eagles, & Falcons of North America: Biology and Natural History''. Smithsonian Institution.Taverner, P. A. (1927). "A study of ''Buteo borealis'', the Red-tailed Hawk, and its varieties in Canada (No. 13)". Canada. Victoria Memorial Museum.

References

{{Taxonbar, from=Q27606536 Harlan's hawk