Grey-headed Goshawk (Accipiter poliocephalus)

Grey-headed Goshawk

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Accipiter poliocephalus | [authority] Gray, 1858 | [UK] Grey-headed Goshawk | [FR] Autour a tete grise | [DE] Aschkopf-Habicht | [ES] Gavilan Cabecigris | [NL] Bleke Sperwer

Subspecies

Genus Species subspecies Region Range
Accipiter poliocephalus AU New Guinea

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

The upperparts are grey, paler on the head and neck; the wings are dark; the underparts are mainly white; the cere and legs are red-orange. The body is 30-38 cm long; females are larger than males.


wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 30 cm size max.: 38 cm
incubation min.: 0 days incubation max.: 0 days
fledging min.: 0 days fledging max.: 0 days
broods: 1   eggs min.: 1  
      eggs max.: 1  

Range

Australasia : New Guinea. The Grey Goshawk is endemic to New Guinea and adjacent islands. It has been recorded from Saibai Island, Queensland, Australian territory in north-western Torres Strait.

Habitat

Occurs in gallery forest, secondary growth, forest edges, and partly cleared areas, where it is reclusive and seldom seen. It does not soar, but is a still solitary hunter that attacks prey from a perch.

Reproduction

A nest was seen near Brown River was in a tall remnant tree in an area of village gardens; the tree was also the site of an active colony of Metallic Starlings (Aplonis metallica). The nest was made typical of the genus, being made of sticks and leaves, and it was located 27 m high in the first main fork of the tree. A presumably incubating bird was observed on the nest on 28 August, only 2 m from active starling nests. Another observed nest at Bonena, Mt. Mura (near Mt. Simpson, southeastern New Guinea) contained a single egg, which was white and heavily marked with buff and olive blotches. The nest was a large compact structure composed of sticks and leafy twigs.

Feeding habits

Feeds on insects and small reptiles, mostly lizards.

Video Grey-headed Goshawk

httpv://www.youtube.com/watch?v=XJsZkB0OTRs

copyright: Martin Kennewell


Conservation

Although this species may have a restricted range, it is not believed to 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 may be moderately small to large, but it is not believed to 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.
Grey-headed Goshawk status Least Concern

Migration

Non-migratory, but juveniles disperse from breeding areas

Distribution map

Grey-headed Goshawk distribution range map

Leave a Reply