Northern Goshawk (Accipiter gentilis)

Northern Goshawk

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Accipiter gentilis | [authority] Linnaeus, 1758 | [UK] Northern Goshawk | [FR] Autour des palombes | [DE] Habicht | [ES] Azor Norteno | [NL] Havik

Subspecies

Monotypic species

Genus

Members of the genus Accipiter are small and medium-sized hawks, often called Sparrow-hawks or Goshawks. The females are almost invariably much larger than the males – in some cases weighing twice as much – a level of size dimorphism only exceptionally reached in any other genus Falconiformes. Their wings are short and rounded; the tail usually quite long. They are well adapted for flying through dense bush. Bird-catching Sparrow-hawks generally have long and slender legs, with slender digits, the middle one being especially long. Goshawks are usually larger, with shorter, thicker tarsi and digits and a shorter middle digit. Some smaller species have goshawk-like feet and vice versa, making it difficult on a world-wide basis to subdivide the genus on this or any other broad basis. Although many accipiters feed upon birds moreso than do other hawks, some species take many mammals, especially squirrels; others take lizards, frogs, snakes, insects, even snails. In these species the legs and digits are sometimes slender, but short. Accipiters are rarely crested, but some have very attractive colour patterns. Black phases are present, especially in the tropical species. One in Australia has the only pure white phase. Accipiter is the largest genus in the family, having about fifty species. It is present worldwide, but is especially rich in Papua-New Guinea, where a small island like New Britain may have three to five endemic species or distinct sub-species.

Physical charateristics

A fairly large hawk with a long tail, rounded wing tips, and a conspicuous pale eyebrow; adult has dark crown, blue-gray back, white underparts with dense gray barring, and conspicuous fluffy white undertail coverts; immature is brown above, buffy below, with dense blurry streaking, undertail coverts are dark-streaked, and tail has wavy dark bands bordered with white and a thin white tip; total length is 53-66 cm, with females averaging lager than males

Listen to the sound of Northern Goshawk

[audio:http://www.planetofbirds.com/MASTER/ACCIPITRIFORMES/Accipitridae/sounds/Northern Goshawk.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 93 cm wingspan max.: 127 cm
size min.: 49 cm size max.: 64 cm
incubation min.: 35 days incubation max.: 38 days
fledging min.: 35 days fledging max.: 38 days
broods: 1   eggs min.: 2  
      eggs max.: 5  

Range

North America, Middle America, Eurasia : widespread

Habitat

During winter the species inhabits a fragmented landscape of forests, clearcuts, wetlands and agricultural lands. Whereas non-forested habitats is only used if large patches of forest are not available.

During breeding both heavily forested with high density of large trees with high canopy; and relatively open habitats both in upland and lowland.

Reproduction

Usually one clutch produced per year, from late April through early May. Clutch is typically two to four eggs, rarely one to five. Eggs are laid every two to three days and incubation usually begins after the second egg is laid. Incubation, conducted principally by the female, takes 28-38 days, hence hatching is asynchronous.

Brooding and feeding of nestlings is performed principally by the female, the male brings food to the nest. The young begin flying at 35-42 days and become independent at about 70 days after hatching. The Goshawk maintains one up to eight alternate nests within a nest area. The next pair is an average three kilometers apart.

Feeding habits

Forages during short flights and with brief prey searches from perches. Also hunts by flying along forest edges, across openings, and through dense vegetation in fast gear. The Goshaek, preys on a wide variety of vertebrates and, occasionally, insects. Prey is taken on the ground, in vegetation, or in the air. Dominant prey include tree anf ground squirrels, ground squirrels, and rabbits. Preys also on birds like grouse, crows, woodpeckers and passerines. During the nesting season, the diet can vary with prey availability. For example, as more fledgling passerines become available, they make up a greater portion of the diet.

Video Northern Goshawk

httpv://www.youtube.com/watch?v=peDDriJPYBw

copyright: youtube


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Accipiter gentilis is a widespread resident across most of Europe, which accounts for less than half of its global range. Its European breeding population is large (>160,000
pairs), and increased substantially between 1970-1990. Although there were declines in several countries during 1990-2000, these were more than compensated for by positive trends elsewhere-notably in the Russian stronghold-and the species underwent a moderate increase overall.
Widespread across Europe apart from England, Ireland and parts of central France. Germany has between 15000-30000 pairs. Russian population 70000-100000 Turkish population 100-1000.
Relatively abundant and widespread in Nearctic and Holarctic; population trends are difficult to determine; no hard evidence of a significant decline in recent decades, but probably declining in some areas primarily as a result of habitat alteration (especially logging), which can be expected to continue; effectiveness of forest management guidelines in providing adequate protection remains to be determined.
Northern Goshawk status Least Concern

Migration

Mainly sedentary; partially migratory in northernmost populations of North America, Fenno-Scandia and Russia. Scale and extent of movements dictated by cycles of prey abundance in Arctic regions. Irruptions occur roughly every decade in North America, with birds reaching South USA and North Mexico. In Fenno-Scandia, movements far less extensive, not normally involving more than a few hundred kilometers. Migrants leave N areas mainly in October-November, returning to breeding zones in March-April.

Distribution map

Northern Goshawk distribution range map

Literature

Title Site-specific variation in partial brood loss in northern goshawks
Author(s): Byholm, P. 2005
Abstract: While many studies have shown that patterns of par..[more]..
Source: Ann. Zool. Fennici 42: 81-90

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Title Ecology of the Northern Goshawk in Fennoscandia
Author(s): R., Korpimki, E. & Byholm, P. 2006
Abstract: Delayed density-dependent mortality induced by del..[more]..
Source: Studies in Avian Biology 31:141-157, 326-369

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Title Age-dependent diet choice in an avian
top predator
Author(s): Christian Rutz, Mark J. Whittingham and Ian Newton
Abstract: Age-dependent breeding performance is arguably one..[more]..
Source: Proc. R. Soc. B (2006) 273, 579-586

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Title Home range size, habitat use, activity patterns and hunting behaviour of urban-breeding Northern Goshawks Accipiter gentilis
Author(s): Rutz C.
Abstract: The Northern Goshawk Accipiter gentilis typically ..[more]..
Source: ARDEA 94 (2): 185-202.

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Title Age at first breeding and fitness in goshawk Accipiter gentilis
Author(s): OLIVER KRGER
Abstract: Age at first breeding has a large influence on fit..[more]..
Source: Journal of Animal Ecology 74 (2), 266-273

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Title Northern Goshawk Diet During the Nesting Season in
Southeast Alaska
Author(s): STEPHEN B. LEWIS et al
Abstract: Northern goshawks (Accipiter gentilis; hereafter, ..[more]..
Source: JOURNAL OF WILDLIFE MANAGEMENT 70(4):1151-1160; 2006

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