UKBirds

Northern Goshawk

Accipiter gentilis

The Northern Goshawk (Old English: gosheafoc, "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.

It is a widespread species that inhabits the temperate parts of the northern hemisphere. In Europe and North America, where there is only one goshawk, it is often referred to (officially and unofficially, respectively) 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).

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 through trees in the forests it lives and nests in. Across most of the species's 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. 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, however adults develop orange-colored eyes. The Northern Goshawk, like all accipiters, exhibits sexual dimorphism, where females are significantly larger than males. Males, being able 10-25% smaller in body are size, are 46-57 cm (18-22 in) long with a 89-105 cm (35-41 in) wingspan. The female is much larger, 58-64 cm (23-25 in) long with a 108-127 cm (43-50 in) wingspan. Males average around 780 g (1.7 lb), with a range of 500 to 1,200 g (1.1 to 2.6 lb). The female can be more than twice as heavy, averaging 1,220 g (2.7 lb) with a range of 820 to 2,200 g (1.8 to 4.9 lb). Following Bergmann's rule, specimens from the northern races tend to be larger-bodied than goshawks near the southern reaches of the species range. The juvenile is brown above and barred brown below. The flight is a characteristic "flap flap, glide", but is sometimes seen soaring in migration, and is capable of considerable, sustained, horizontal speed in pursuit of prey with speeds of 38 mph (61 km/h) 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.