Red Goshawk

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Image:RedGoshawk.jpg

Common Name: Red Goshawk
Scientific Name: Erythrotriorchis radiatus

Size: 17.7-23.3 inches (45-60 cm); Wingspan: 39.4-53.2 inches (100-135 cm)

Habitat: Oceania; endemic to Australia. Historically, it ranged in northern and eastern Australia, north of c.33°S in the east, and 19°S in the west, but its range has contracted from south of 28°S in the east, and it is now virtually extinct in New South Wales. Recent surveys suggest breeding is continuous across northern Australia.

It lives in coastal and sub-coastal, tall, open forests and woodlands, tropical savannas traversed by wooded or forested rivers and along the edges of rain forests. It builds stick nests in trees taller than 20 m within 1 km of a watercourse or wetland. It hunts in open forests and gallery forests, with a home range of up to 200 km2, taking mostly medium to large birds, but also snakes. In winter in eastern Australia, it appears to move from nest-sites in the ranges to coastal plains, where it often feeds on waterbirds taken from open wetlands.

Status: Endangered to Vulnerable. Global population: 700 adult individuals with a decreasing population trend. The population was estimated at 700 pairs in 2010, including 100 pairs on Tiwi Islands, probably a separate subpopulation, and 600 pairs elsewhere across northern Australia from the Kimberley through the Northern Territory and through Queensland to northern New South Wales. The population may be declining owing to habitat loss in at least eastern Queensland; the rate of decline has not been quantified but is not suspected to be rapid. Widespread clearance for agriculture probably caused the historical decline in north-eastern New South Wales and southern Queensland. Continuing clearance is affecting more northerly populations. Even if riparian strips are left uncleared, pairs usually nest in the tallest trees that are then exposed to storm damage and other disturbance. Clearing of forest for acacia plantations has rendered some territories on Melville Island unproductive. Egg-collecting may result in the failure of some nests as does the burning of nest trees or disruption of breeding by fire. Shooting by pigeon and poultry owners, and possibly pesticides, causes some mortality of individuals and may result in temporary local scarcity. Prey abundance may be reduced by loss or degradation of freshwater wetlands, loss of hollow-bearing trees in which prey breed, over-grazing by livestock and feral herbivores, and changed fire regimes.

The Red Goshawk is listed nationally as vulnerable under the federal Environmental Protection and Biodiversity Conservation Act 1999 EPBC and is listed as endangered in Queensland and New South Wales and vulnerable in the Northern Territory. It is also listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora CITES.

Diet: Mostly birds, especially parrots and pigeons; rarely they also prey on mammals, reptiles, and large insects.

Early and late in the day, they hunt from concealed perches in the trees. In the middle of the day, they use long transects, quartering through or above the canopy, or search from a high soaring position. They attack by a stealthy glide, direct chase, or may stoop from a height.

Nesting: Sexes are similar. The plumage is generally rufous and the head streaked with black and white, having more white on the face and throat. The body and upper wings are marked with black. Flight feathers and tail are barred gray, dark above and light below. The underside (belly and under wing coverts) are rufous with slight black ticking. The female has a paler belly than the male. Irises are yellow and the cere is pale gray. Legs and feet are yellow.

Juveniles (first year) have less streaking on the head, brown irises, blue-gray ceres and pale gray or creme feet and legs.

The nest is built in an exposed fork of a tall emergent. The nest is a stick platform lined with green leaves, 60–120 cm across and 30–50 cm deep. The emergent layer contains a small number of very large trees called emergents, which grow above the general canopy, reaching heights of 45–55 m, although on occasion a few species will grow to 70–80 m tall.

The egg-laying season is from May to October in the tropical north, and August to October in the east. Incubation takes 40 days, the nestling period 51–53 days, and juveniles remain dependent for 2–3 months

Cool Facts: The Red Goshawk used to be regarded as a very large member of the goshawk subfamily, Accipitrinae, but it is now believed that the resemblance to these other birds is convergent. Experts now group the Red Goshawk with the superficially dissimilar Black-breasted buzzard (Hamirostra melanosternon) and square-tailed kite (Lophoictinia isura) as one of the Australasian old endemic raptors. It is believed that the ancestors of these birds, possibly together with a handful of species from South-east Asia and Africa, occupied Gondwana and over millions of years have diverged into their current forms.



Found in Songbird ReMix Birds of Prey Volume 5: Falcons, Hawks & Eagles

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