Birding/ Bird watching in Sweden - Northern Goshawk / Duvhök

Northern Goshawk, Accipiter gentilis, Duvhök

Length: 69 cm
Wingspan: 96 to 127 cm.
Weight: 800 to 1509 g
Longevity: 19 years
Distinctive Feature •
Similar Species • From opus at www.birdforum.net the forum for wild birds and birding.
Female / Male / Juvenile • From opus at www.birdforum.net the forum for wild birds and birding.

The Northern Goshawk (Accipiter gentilis), called Duvhök in Skåne , is a medium-large raptor in the family Accipitridae, which also includes other extant diurnal raptors, such as eagles, buzzards and harriers. As a species in the genus Accipiter, the goshawk is often considered a "true hawk".

The scientific name is Latin; Accipiter is "hawk", from accipere, "to grasp", and gentilis is "noble" or "gentle" because in the Middle Ages only the nobility were permitted to fly goshawks for falconry.

This species was first described under its current scientific name by Linnaeus in his Systema naturae in 1758.

It is a widespread species that inhabits many of the temperate parts of the Northern Hemisphere. The Northern Goshawk is the only species in the genus Accipiter found in both Eurasia and North America. It may have the second widest distribution of any true member of the family Accipitridae, behind arguably only the Golden Eagle (Aquila chrysaetos), which has a broader range to the south of Asia than the goshawk.

The only other acciptrid species to also range in both North America and Eurasia according to current opinion, is the more Arctic-restricted rough-legged buzzard (Buteo lagopus). Except in a small portion of southern 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 at nearly any time of the fall depending on latitude.

Distribution
The Northern Goshawk has a large circumpolar distribution. In Eurasia, it is found in most areas of Europe excluding Ireland and Iceland. It has a fairly spotty distribution in western Europe (e.g. Great Britain, Spain, France) but is more or less found continuously through the rest of the continent.

Their Eurasian distribution sweeps continuously across most of Russia, excluding the fully treeless tundra in the northern stretches, to the western limits of Siberia as far as Anadyr and Kamchatka. In the Eastern Hemisphere, they are found in their southern limits in extreme northwestern Morocco, Corsica and Sardinia, the "toe" of Italy, southern Greece, Turkey, the Caucasus, Sinkiang's Tien Shan, in some parts of Tibet and the Himalayas, western China and Japan.

In winter, Northern Goshawks may be found rarely as far south as Taif in Saudi Arabia and perhaps Tonkin, Vietnam.

In North America, they are most broadly found in the western United States, including Alaska, and western Canada. Their breeding range in the western contiguous United States largely consists of the wooded foothills of the Rocky Mountains and many other large mountain ranges from Washington to southern California extending east to central Colorado and westernmost Texas.

Somewhat discontinuous breeding populations are found in southeastern Arizona and southwestern New Mexico, thence also somewhat spottily into western Mexico down through Sonora and Chihuahua along the Sierra Madre Occidental as far as Jalisco and Guerrero, their worldwide southern limit as a breeding species.

The goshawk continues east through much of Canada as a native species, but is rarer in most of the eastern United States, especially the Midwest where they are not typically found outside the Great Lakes region, where a good-sized breeding population occurs in the northern parts of Minnesota, Illinois, Michigan and somewhat into Ohio; a very small population persists in the extreme northeast corner of North Dakota.

They breed also in mountainous areas of New England, New York, central Pennsylvania and northwestern New Jersey, sporadically down to extreme northwestern Maryland and northeastern West Virginia.[8] Vagrants have been reported in Ireland, North Africa (central Morocco, northern Algeria, Tunisia, Libya, Egypt); the Arabian Peninsula (Israel, Jordan, Saudi Arabia), southwest Asia (southern Iran, Pakistan), western India (Gujarat) and on Izu-shoto (south of Japan) and the Commander Islands, and in most of the parts of the United States where they do not breed.

Distribution map of Northern Goshawk (Accipiter gentilis) according to IUCN version 2018.2

By SanoAK: Alexander Kürthy - Made with Natural Earth.
Free vector and raster map data @ naturalearthdata.com. Range map from BirdLife International 2016.
Accipiter gentilis. The IUCN Red List of Threatened Species 2016: e.T22695683A93522852.
https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22695683A93522852.en.
Downloaded on 29 January 2019 as visual indicator of distribution., CC BY-SA 4.0,
https://commons.wikimedia.org/w/index.php?curid=76189311

Habitat
Northern Goshawks can be found in both deciduous and coniferous forests. While the species might show strong regional preferences for certain trees, they seem to have no strong overall preferences nor even a preference between deciduous or coniferous trees despite claims to the contrary.

More important than the type of trees are the composition of a given tree stand, which should be tall, old-growth with intermediate to heavy canopy coverage (often more than 40%) and minimal density undergrowth, both of which are favorable for hunting conditions. Also, goshawks typically require close proximity to openings in which to execute additional hunting.

More so than in North America, the goshawks of Eurasia, especially central Europe, may live in fairly urbanized patchworks of small woods, shelter-belts and copses and even use largely isolated trees in central parts of Eurasian cities. Even if they are way more wary of human presence than the Eurasian sparrowhawk, northern goshhawks are known to live in some relatively densely wooded areas of big cities of Central Europe, such as Berlin and Hamburg; it is a relatively new phenomenon that started in the 20th century.

Access to waterways and riparian zones of any kind is not uncommon in goshawk home ranges but seems to not be a requirement. Narrow tree-lined riparian zones in otherwise relatively open habitats can provide suitable wintering habitat in the absence of more extensive woodlands.

The Northern Goshawk can be found at almost any altitude, but recently is typically found at high elevations due to a paucity of extensive forests remaining in lowlands across much of its range. Altitudinally, goshawks may live anywhere up to a given mountain range's tree line, which is usually 3,000 m in elevation or less.

The northern limit of their distribution also coincides with the tree line and here may adapt to dwarf tree communities, often along drainages of the lower tundra. In winter months, the northernmost or high mountain populations move down to warmer forests with lower elevations, often continuing to avoid detection except while migrating.

A majority of goshawks around the world remain sedentary throughout the year.

Range map from www.oiseaux.net - Ornithological Portal Oiseaux.net

www.oiseaux.net is one of those MUST visit pages if you're in to bird watching. You can find just about everything there

Description
The Northern Goshawk has relatively short, broad wings and a long tail, typical for Accipiter species and common to raptors that require maneuverability within forest habitats.[3] For an Accipiter, it has a relatively sizeable bill, relatively long wings, a relatively short tail, robust and fairly short legs and particularly thick toes.

Across most of the species' range, it is blue-grey above or brownish-grey with dark barring or streaking over a grey or white base color below, but Asian subspecies in particular range from nearly white overall to nearly black above. Goshawks tend to show clinal variation in color, with most goshawks further north being paler and those in warmer areas being darker but individuals can be either dark in the north or pale in the south.

Individuals that live a long life may gradually become paler as they age, manifesting in mottling and a lightening of the back from a darker shade to a bluer pale color. Its plumage is more variable than that of the Eurasian sparrowhawk (Accipiter nisus), which is probably due to higher genetic variability in the larger goshawk.

The juvenile Northern Goshawk is usually a solid to mildly streaky brown above, with many variations in underside color from nearly pure white to almost entirely overlaid with broad dark cinnamon-brown striping. Both juveniles and adults have a barred tail, with 3 to 5 dark brown or black bars.

Adults always have a white eye stripe or supercilia, which tends to be broader in northern Eurasian and North American birds. 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 typically develop orange-colored eyes, though some may have only brighter yellow or occasionally ochre or brownish eye color. Moulting starts between late March and late May, the male tends to moult later and faster than the female.

Moulting results in the female being especially likely to have a gap in its wing feathers while incubating and this may cause some risk, especially if the male is lost, as it inhibits her hunting abilities and may hamper her defensive capabilities, putting both herself and the nestlings in potential danger of predation.

The moult takes a total of 4–6 months, with tail feathers following the wings then lastly the contour and body feathers, which may not be completely moulted even as late as October.

Juvenile (left) and adult by Louis Agassiz Fuertes

By Elon Howard Eaton (1866-1935, author), Louis Agassiz Fuertes (artist, 1874-1927)
Birds of New York (New York State Museum. Memoir 12), Albany: University of the State of New York.
Plates by Fuertes later reproduced in Birds of America (1917?) by Thomas Gilbert Pearson (1873-1943) et al.

Although existing wing size and body mass measurements indicate that the Henst's goshawk (Accipiter henstii) and Meyer's goshawk (Accipiter meyerianus) broadly overlap in size with this species, the Northern Goshawk is on average the largest member of the genus Accipiter, especially outsizing its tropic cousins in the larger Eurasian races.

The Northern Goshawk, like all Accipiters, exhibits sexual dimorphism, where females are significantly larger than males, with the dimorphism notably greater in most parts of Eurasia. Linearly, males average about 8% smaller in North America and 13% smaller than females in Eurasia, but in the latter landmass can range up to a very noticeable 28% difference in extreme cases.

Male Northern Goshawks are 46 to 61 cm long and have a 89 to 105 cm wingspan. The female is much larger, 58 to 69 cm long with a 108 to 127 cm wingspan. In a study of North American goshawks (A. g. atricapillus), males were found to average 56 cm in total length, against females which averaged 61 cm.

Males from six subspecies average around 762 g in body mass, with a range from all races of 357 to 1,200 g. The female can be up to more than twice as heavy, averaging from the same races 1,150 g with an overall range of 758 to 2,200 g.

Among standard measurements, the most oft-measured is wing chord which can range from 286 to 354 mm in males and from 324 to 390 mm in females. Additional, the tail is 200–295 mm, the culmen is 20–26.3 mm and the tarsus is 68–90 mm.

Length: 69 cm

Wingspan: 96 to 127 cm.

Weight: 800 to 1509 g

Longevity: 19 years

Distinctive Feature

•

Similar Species

•

From opus at www.birdforum.net the forum for wild birds and birding.

Female / Male / Juvenile

•

From opus at www.birdforum.net the forum for wild birds and birding.

Illustration of the formidable talons and beak,
which are both proportionately large relative to their size,
and give them a predatory advantage over many other raptors

By Internet Archive Book Images
No restrictions, https://commons.wikimedia.org/w/index.php?curid=43472904

Similar species
The juvenile plumage of the species may cause some confusion, especially with other Accipiter juveniles. Unlike other northern Accipiters, the adult Northern Goshawk never has a rusty color to its underside barring.

In Eurasia, the smaller male goshawk is sometimes confused with a female sparrowhawk, but is still notably larger, much bulkier and has relatively longer wings, which are more pointed and less boxy.

Sparrowhawks tend to fly in a frequently flapping, fluttering type flight. Wing beats of Northern Goshawks are deeper, more deliberate, and on average slower than those of the Eurasian sparrowhawk or the two other North American Accipiters.

The classic Accipiter flight is a characteristic "flap flap, glide", but the goshawk, with its greater wing area, can sometimes be seen steadily soaring in migration (smaller Accipiters almost always need to flap to stay aloft).

In North America juveniles are sometimes confused with the smaller Cooper's hawk (Accipiter cooperii), especially between small male goshawks and large female Cooper's hawks. Unlike in Europe with sparrowhawks, Cooper's hawks can have a largish appearance and juveniles may be regularly mistaken for the usually less locally numerous goshawk.

However, the juvenile goshawk displays a heavier, vertical streaking pattern on chest and abdomen, with the juvenile Cooper's hawk streaking frequently (but not always) in a “teardrop” pattern wherein the streaking appears to taper at the top, as opposed to the more even streaking of the goshawk.

The goshawk sometimes seems to have a shorter tail relative to its much 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 rarely occur due to variation in seasonal condition and food intake at time of weighing.

Rarely, in the southern stretches of its Asian wintering range, the Northern Goshawk may live alongside the crested goshawk (Accipiter trivirgatus) which is smaller (roughly Cooper's hawk-sized) and has a slight crest as well as a distinct mixture of denser streaks and bars below and no supercilia.

Northern Goshawks are sometimes mistaken for species even outside of the genus Accipiter especially as juveniles of each respective species. In North America, four species of buteonine hawk (all four of which are smaller than goshawks to a certain degree) may be confused with them on occasion despite the differing proportions of these hawks, which all have longer wings and shorter tails relative to their size.

A species so similar it is sometimes nicknamed the “Mexican goshawk”, gray hawk (Buteo plagiatus) juveniles (overlapping with true goshawks in the southwest United States into Mexico) have contrasting face pattern with bold dusky eye-stripes, dark eyes, barred thighs and a bold white “U” on the uppertail coverts.

The roadside hawk (Rupornis magnirostris) (rarely in same range in Mexico) is noticeably smaller with paddle-shaped wings, barred lower breast and a buff “U” on undertail coverts in young birds. Somewhat less likely to confuse despite their broader extent of overlap are the red-shouldered hawk (Buteo lineatus) which have a narrow white-barred, dark-looking tail, bold white crescents on their primaries and dark wing edges and the broad-winged hawk (Buteo playpterus) which also has dark wing edges and a differing tapered wing shape.

Even wintering gyrfalcon (Falco rusticolus) juveniles have been mistaken for goshawks and vice versa on occasion, especially when observed distantly perched. However, the bulkier, broader headed yet relatively shorter tailed falcon still has many tell-tale falcon characteristics like pointed, longer wings, a brown malar stripe as well as its more extensive barring both above and below.

Listen to the Northern Goshawk

Sound from www.xeno-canto.org

Remarks from the Recordist

Recorded with my ZOOM H5 Handy Recorder

Sitting in top of a tree. Starts calling and take off and we can hear the bird calling while disappearing

Relationship with humans

Human culture
The Northern Goshawk appears on the flag and coat of arms 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 goshawk features in Stirling Council's coat of arms via the crest of the Drummond Clan.

In falconry
The name "goshawk" is a traditional name from Anglo-Saxon gōshafoc, literally "goose hawk". The name implies prowess against larger quarry such as wild geese, but were also flown against crane species and other large waterbirds.

The name "goose hawk" is somewhat of a misnomer, however, as the traditional quarry for goshawks in ancient and contemporary falconry has been rabbits, pheasants, partridge, and medium-sized waterfowl, which are similar to much of the prey the species hunts in the wild.

A notable exception is in records of traditional Japanese falconry, where goshawks were used more regularly on goose and crane species. In ancient European falconry literature, goshawks were often referred to as a yeoman's bird or the "cook's bird" because of their utility as a hunting partner catching edible prey, as opposed to the peregrine falcon, also a prized falconry bird, but more associated with noblemen and less adapted to a variety of hunting techniques and prey types found in wooded areas.

The Northern Goshawk has remained equal to the peregrine falcon in its stature and popularity in modern falconry.

Iranian falconer with a trained goshawk

By Antoin Sevruguin - National Museum of Ethnology in Leiden, The Netherlands

Goshawk hunting flights in falconry typically begin from the falconer's gloved hand, where the fleeing bird or rabbit is pursued in a horizontal chase.

The goshawk's flight in pursuit of prey is characterized by an intense burst of speed often followed by a binding maneuver, where the goshawk, if the prey is a bird, inverts and seizes the prey from below.

The goshawk, like other accipiters, shows a marked willingness to follow prey into thick vegetation, even pursuing prey on foot through brush.[369] Goshawks trained for falconry not infrequently escape their handlers and, extrapolated from the present day British population which is composed mostly of escaped birds as such, have reasonably high survival rates, although many do die shortly after escape and many do not successfully breed.

The effect of modern-day collection of Northern Goshawks for falconry purposes is unclear, unlike some falcon species which can show regional declines due to heavy falconry collections but can increase in other areas due to established escapees from falconers.

Conservation status

Least Concern (IUCN 3.1)

IUCN Red List of Threatened Species. 2013. Retrieved 26 November 2013.

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