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The northern goshawk (Old English: ''gōsheafoc'', "goose-hawk"), ''Accipiter gentilis'', is a medium-large bird of prey in the family Accipitridae, which also includes other diurnal raptors, such as eagles, buzzards and harriers. As a species in the ''Accipiter'' genus, the goshawk is often considered a true "hawk". It is a widespread species that inhabits the temperate parts of the Northern Hemisphere. It is the only species in the ''Accipiter'' genus found in both Eurasia and North America. With the exception of Asia, it is the only species of "goshawk" in its range and it is thus often referred to, both officially and unofficially, as simply the "goshawk". It is mainly resident, but birds from colder regions migrate south for the winter. In North America, migratory goshawks are often seen migrating south along mountain ridge tops in September and October. This species was first described by Linnaeus in his ''Systema naturae'' in 1758 under its current scientific name.〔 The northern goshawk appears on the flag of the Azores. The archipelago of the Azores, Portugal, takes its name from the Portuguese language word for goshawk, (''açor''), because the explorers who discovered the archipelago thought the birds of prey they saw there were goshawks; later it was found that these birds were kites or common buzzards (''Buteo buteo rothschildi''). == Description == The northern goshawk is the largest member of the genus ''Accipiter''.〔 It is a raptor with short, broad wings and a long tail, both adaptations to manoeuvring within its forest habitat. Across most of the species' range, it is blue-grey above and barred grey or white below, but Asian subspecies in particular range from nearly white overall to nearly black above. The European northern goshawk can be easily distinguished from its north American cousin. Mature European goshawks have horizontal black bars on the breast while North American goshawks have vertical barring. The juvenile is brown above and barred brown below. Juveniles and adults have a barred tail, with dark brown or black barring. Adults always have a white eye stripe. In North America, juveniles have pale-yellow eyes, and adults develop dark red eyes usually after their second year, although nutrition and genetics may affect eye color as well. In Europe and Asia, juveniles also have pale-yellow eyes while adults develop orange-colored eyes. The northern goshawk, like all accipiters, exhibits sexual dimorphism, where females are significantly larger than males. Males, being the smaller sex by around 10–25%, are long and have a wingspan.〔〔 The female is much larger, long with a wingspan.〔〔 Males average around , with a range of .〔 The female can be more than twice as heavy, averaging with a range of .〔 Among standard measurements, the wing chord is , the tail is , the culmen is and the tarsus is .〔〔〔 In Eurasia, the species follows Bergmann's rule: specimens from the northern races generally are larger-bodied than goshawks near the southern reaches of the species range.〔 Going on wing chord length, ''A. g. apache'', found in Mexico to Arizona and New Mexico, is the largest subspecies at an average of and is larger than more northern subspecies in that continent, thus running contrary to Bergmann's rule. ''A. g. fujiyamae'' of Japan is the smallest race, at in wing chord length.〔 In Europe, goshawks from Finland or of Finnish ancestry are prized as bigger than other goshawks. The flight is a characteristic "flap flap, glide", but the bird is sometimes seen soaring in migration, and is capable of considerable, sustained, horizontal speed in pursuit of prey with speeds of reported.〔 Goshawks are sometimes confused with gyrfalcons, especially when observed in high speed pursuit, with their wingtips drawn backward in a falcon-like profile. In Eurasia, the male is sometimes confused with a female sparrowhawk, but is larger, much bulkier and has relatively longer wings. In North America, juveniles are sometimes confused with the smaller Cooper's hawk; however, the juvenile goshawk displays a heavier, vertical streaking pattern on their chest and abdomen and sometimes appears to have a shorter tail due to its much larger and broader body. Although there appears to be a size overlap between small male goshawks and large female Cooper's hawks, morphometric measurements (wing and tail length) of both species demonstrate no such overlap, although weight overlap can occur due to variation in seasonal condition and food intake at time of weighing. In North America, the sharp-shinned hawk is markedly smaller. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Northern goshawk」の詳細全文を読む スポンサード リンク
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