Difference between revisions of "Black-breasted buzzard"

Latest revision as of 09:59, November 19, 2019

Black-breasted buzzard
Scientific classification
Kingdom Information
Domain	Eukaryota
Kingdom	Animalia
Subkingdom	Bilateria
Branch	Deuterostomia
Phylum Information
Phylum	Chordata
Sub-phylum	Vertebrata
Infraphylum	Gnathostomata
Class Information
Superclass	Tetrapoda
Class	Aves
Sub-class	Neornithes
Infra-class	Neoaves
Order Information
Order	Accipitriformes
Sub-order	Accipitres
Family Information
Superfamily	Accipitroidea
Family	Accipitridae
Sub-family	Milvinae
Genus Information
Genus	Hamirostra
Species Information
Species	H. melanosternon
Population statistics
Population	1,000-10,000 (2016 est.)
Conservation status	Least concern[1]

The black-breasted buzzard (Hamirostra melanosternon) is a species of bird of prey of the family Accipitridae, found over much of Australia.

Description

The black-breasted buzzard is large, with a body length of 51.1 to 24 inches, a wingspan of 55.5 to 61.4 inches, and weigh 42.1 to 46.9 ounces. Females are slightly larger than males. Adults are predominately black, with reddish-brown mottling on the back and upper wings; the nape, thighs and lower part of the abdomen are almost completely reddish. The wings are lighter in color underneath, and are white at the base of the primary flight feathers; the leading edge of the primaries are tipped in black. The eyes are brown, and the tail is always gray-brown, both in the young and in the adults.

Predominantly silent, even during aerial courtship, the black-breasted buzzard emits vocalizations almost exclusively during interactions with other species. When disturbed by large passerines or smaller birds of prey, or when it attacks other birds, its main call is a weak kukukukuku^[2].

Range and habitat

The black-breasted buzzard is found in much of Australia^[3], where it is present on almost all the territory and on some nearby islands; it is completely absent in areas of southern and southeastern Australia with a wet temperate climate^[4].

Present in a vast range of inland environments, the black-breasted buzzard is often found in the vicinity of tree-lined watercourses, which constitute its preferred nesting habitat. This bird of prey hunts mainly in the thickets with scattered trees and in grasslands. It is also present in the open forests and eucalyptus groves, in the shrubby steppes, in the arid moors and in open territories, including grasslands and sandy deserts, ranging from sea level to 3,000 feet in elevation.

Hunting

The black-breasted buzzard goes in search of prey standing in the air, sailing at medium-low height above the open expanses or flying over the tops of the trees. It proceeds gliding back and forth over a certain area, plummeting to seize prey on the ground or occasionally, within the trees. Prey items include mammals such as rabbits and small rodents, birds, lizards and small snakes, some insects and carrion. It has been recorded that this species engages in group hunting.

Despite being an active predator, the black-breasted buzzard is also an egg eater, exhibiting a unique behavior that distinguishes this species from most other raptors. When it hunts for nestlings and eggs of species of ground-nesting birds such as the emu (Dromaius novaehollandiae), the brolga crane (Grus rubicunda) and the Australian bustard (Ardeotis australis), the black-breasted buzzard tries to drive away the adult birds from the nest by frightening them with an opening-wing threatening display. Once successful, the eggs are broken with the beak or by slamming them on the ground.

If the eggs are from the larger emus, the black-breasted buzzard will pick up and drop stones on them while either standing or in flight, one of only two birds of prey demonstrated to use tools^[5]. The young black kites raised far away from their parents also exhibit this use of tools, which shows that this special behavior is innate and not learned, yet young birds must first learn to recognize eggs as a potential food source^[6].

Reproduction

The black-breasted buzzard reproduces in any area of ​​its range, despite showing preference for some areas. Breeding and nesting takes place during the rainy season, which generally runs from June to November, with a peak between August and October. During the breeding season, pairs fly over the territory in which they nest for hours and hours, ascending and descending in a ritual that involves simulated attacks, turns and dodges. This species is monogamous, and the pairs are solitary^[7].

The nest of the red kite is about 3 to 4 feet wide and up to 2 feet deep, made of twigs and lined with green leaves. It is generally located 18 to 25 feet high from the ground, usually at the fork of a branch, in both living and dead trees. The brood normally includes two eggs, but sometimes even only one or as many as three. The incubation is carried out to the same extent by both parents for a period of about 36-40 days, and the nestlings fly off after 56-60 days, after which they continue to depend on their parents for about two months.

Threats

The black-breasted buzzard has a wide range, yet with a small population, estimated to be at 670 to 6700 adult birds^[8]; this number is decreasing, but at a slow pace, less than 30% in ten years.

References