Grey Goshawk

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(New page: '''Common Name:''' Grey Goshawk<br> '''Scientific Name:''' Accipiter novaehollandiae '''Size:''' 15.7-21.6 inches (40-55 cm); '''Wingspan:''' 27.5-43.3 inches (70-110 cm) '''Habitat:''' ...)
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'''Common Name:''' Grey Goshawk<br>
'''Common Name:''' Grey Goshawk<br>
'''Scientific Name:''' Accipiter novaehollandiae
'''Scientific Name:''' Accipiter novaehollandiae
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'''This 3D Model is found in [ Songbird ReMix Birds of Prey Volume II: Hawks of the Old World]'''
'''This 3D Model is found in [ Songbird ReMix Birds of Prey Volume II: Hawks of the Old World]'''. Grey Phase available in [ Songbird Remix Freebie Downloads].

Revision as of 17:25, 25 November 2014


Common Name: Grey Goshawk
Scientific Name: Accipiter novaehollandiae

Size: 15.7-21.6 inches (40-55 cm); Wingspan: 27.5-43.3 inches (70-110 cm)

Habitat: Oceania/Australia; it is found along the coasts of northern, eastern and south-eastern Australia, Tasmania and rarely Western Australia, the Lesser Sunda Islands, Moluccas, New Guinea, and the Solomon Islands.

It is most commonly found throughout its range in forests or woodland. In Australia and Tasmania, it is a bird of wooded country, extending round the continent to the north-west (Kimberley Mountains) and avoiding the desert regions of the interior. It is resident where it occurs and does not migrate. The New Guinea and Island races can be found in dense jungle, both in mountains and near the coast. In heavily forested areas, it favors secondary growth or open clearings, villages and native gardens.

Status: Vulnerable. Global population: 2500-9999 mature individuals. The grey goshawk was listed as threatened on the Victorian Flora and Fauna Guarantee Act 1988. In 2007, it was up-listed on the advisory list of threatened vertebrate fauna in Victoria, to vulnerable. The current population trend appears to be again in decline due to ongoing habitat destruction and human persecution of this hawk.

Diet: Diet depends on the subspecies. The larger Australian form takes birds up to the size of a fruit pigeon, small megapodes, mammals up to the size of a rabbit, reptiles, including snakes, and some insects. The smaller island forms eat small birds, small ground mammals, lizards, and large insects, with probably a larger proportion of insects and lizards than the continental race.

Avian prey is taken either on the wing or on the ground; mammalian, reptile and insect prey on the ground or from the branches of trees. The hawk hides in the cover of woodlands or forest, and attacks birds and other prey either in the open or inside the cover. It will plunge into dense vegetation in pursuit of prey on occasion. Sometimes it soars almost with the ease of a buzzard. The larger Australian forms are less agile than some of the small island forms and hunt either from perches within woodland, or by flying low through the trees in the hope of surprising prey. The white morph birds benefit from their similarity to the cockatoo when approaching other birds.

In all races, sexual dimorphism decides prey choice. The smaller males tend to take more birds while the larger females take more mammals and reptiles on the ground.

Nesting: The adult markings in Australia are variable. With the white morph, it is pure white with reddish orange eyes, and yellow cere and feet. White birds predominate in the south-east and in the north-west. In Tasmania all birds are white. Immatures in the white morph are pure white like the adult. The eye color is brown, becoming reddish, at about two months old. The cere and feet are yellow.

With the grey morph, it is clear pale grey above, except for faint white barring on the rump, white edges to inner webs of tail quills, and about eleven dark grey bars on the tail quills. Below, the throat is white, the sides of the face and the neck pale grey. Its breast is barred grey and white; the rest of the underside, including under-wing is white with some faint grey barring on thighs. Tail quills below are silvery, faintly barred grey on inner webs. Primaries are grey and white; secondaries pale grey, barred basally on inner webs with grey and white. The eye is red and the cere and legs are yellow. Grey morph birds predominate in the center portion of the Australian range. Females are much larger than males and, in the grey morph, rather darker and more heavily barred; otherwise alike. Immatures in grey morph differs from the adult in being greyer generally, more heavily barred below, with a grey wash over much of the underside. The cere and feet are yellow.

The New Guinea races, with white morph, form intermediate links between the large Australian birds and the smaller, brightly colored island races. Almost all the island races of this species differ from the nominate race in being grey above and chestnut, rufous, or vinous below, the underside being either plain or more or less barred, the grey upper side varying greatly in shade from pale slate to almost black, sometimes with a rufous collar. The general trend is for the races inhabiting tropical forests to be darker above and more richly rufous below.

In general, the paler forms among the island races are from the western part of the range, and the darkest forms occur in the Solomon Islands. The adult in white morph is impossible to confuse with anything but a white cockatoo; the same applies to the white New Guinea forms. The pale grey Australian form is likewise much paler than, and easy to distinguish from, the slate-colored and strongly barred Australian Goshawk (Accipiter fasciatus). The plain-breasted Island forms, with rufous or vinous under sides and grey or slatey upper sides, are also unmistakable in adult plumage. They appear bulkier in flight than other Accipiter species in the same area. The barred island forms are more difficult to distinguish from the forms of the Collared Sparrow-hawk (Accipiter cirrhocephalus) and Australian Goshawk with which they share a range, but are much more uniform and brighter rufous below, and less clearly barred.

Grey and white goshawks interbreed freely and partner for life. The breeding season is from August to December. The nest is usually placed in large Eucalyptus, often well out on a horizontal limb, at an average of about 60 feet above the ground. It is a flat structure made of fine sticks and lined with green leaves, built by the birds themselves. Both sexes build, breaking off the twigs from dead branches. Nest repair or the construction of a new nest may occupy from six weeks to two months. Eggs are laid in clutches of three in September and October.

Both sexes are known to incubate, but the female usually incubates alone and the male seldom visits the nest except to bring prey; when females have been shot the male does not necessarily incubate the eggs, but obtains another mate. When the young hatch they are brooded closely by the female; the male then spends little time near the nest, but brings all the prey which is received by the female and fed by her to the young. From egg-laying to fledging young takes a little over two months.

Cool Facts: The white morph is the only bird of prey in the world to be entirely white.

This 3D Model is found in Songbird ReMix Birds of Prey Volume II: Hawks of the Old World. Grey Phase available in Songbird Remix Freebie Downloads.

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