Black-shouldered Kite

Identification

The adult black-shouldered kite is around 35 cm (14 in) in length, with a wingspan of between 80 and 100 cm (31 and 39 in). The female is slightly heavier, weighing on average around 300 g (11 oz) compared to the male's average weight of 260 g (9.2 oz). The sexes have similar plumage. The crown, neck and upperparts are pale grey, while the head and underparts are white. A black comma-shaped marking lies in front of and stretches over and behind the eye, which is deep red and surrounded by a black orbital ring. The leading edge of the outer wing is black. When perched, this gives the species its prominent black "shoulders". The central rectrices of the tail are pale grey, while the rest of the tail feathers are white. The bill is short with a sharp, hooked tip to the upper mandible. Its nostrils and the cere are bright or dull yellow and the bill is black. The legs and feet are also yellow or golden-yellow, and the feet have three toes facing forwards and one toe facing backwards.<p>The juvenile has a white forehead and chin and rusty brown neck, nape and breast with darker streaks. The back and wings are mottled buff or brown. There is a less distinctive dark shoulder patch, but a larger comma-shaped patch over the eyes. The eyes themselves are dark brown. The bill is black with a horn-coloured cere.<p>Black-shouldered kites spiral into the wind like a kestrel. They soar with V-shaped up-curved wings, the primaries slightly spread and the tail widely fanned, giving the tail a squarer appearance and visible 'fingers' on the wings. In level flight progress is rather indirect. Their flight pattern has been described as 'winnowing' with soft steady beats interspersed with long glides on angled wings. They can most often be seen hovering with wings curved and tail pointing down.<p>The black-shouldered kite is very similar to the related letter-winged kite (E. scriptus), but has the black mark above and behind the eye, a white rather than grey crown, and shows all-white underparts in flight except for the black markings on the shoulder, dark wingtips, and a small black patch on the underwing. It is slightly larger than the nankeen kestrel (Falco cenchroides). The latter species lacks wing markings and has pale brown plumage. It keeps its wings level when soaring, and has a faster wingbeat when hovering. The grey falcon (Falco hypoleucos) has somewhat similar coloration to the black-shouldered kite but is bulkier and heavier overall and lacks the black markings. Its wings are barred, and it preys on birds. The grey goshawk (Accipiter novaehollandiae) has wider more rounded wings, underwing markings and glides with lowered wings.<p>The black-shouldered kite is generally silent, except in the breeding season when its calls, though weak, can be persistent. It primarily utters a clear whistled chee, chee, chee call in flight and while hovering, or a hoarse wheezing skree-ah when perched. A short high whistle is the primary contact call between a pair, while a harsh scraping call is the most common call used by the female and large young, and brooding females call to their young with a deep, soft, frog-like croak.<p>A variety of different calls have been recorded from captive birds, including harsh, harmonic, chatter and whistle vocalisations. Harsh calls were made when a bird was alarmed or agitated, whistle-type calls were emitted in general contexts, sometimes monotonously, and shorter duration "chatter" calls were given when a bird sighted a human near the enclosure.

Taxonomy

The black-shouldered kite was first described by English ornithologist John Latham in 1801, as Falco axillaris. Its specific name is derived from the Latin axilla, meaning "armpit", relating to the dark patches under the wings. He reported the description came from a bird that had been kept for two months in the early colony.The species description was based on one of four paintings by Australian painter Thomas Watling of a bird in the Sydney district in the 1790s.<p>English naturalist John Gould described the same species as Elanus notatus in 1838 from a specimen from New South Wales, apparently unaware of Latham's description. English zoologist George Robert Gray followed Latham using the binomial Elanus axillaris in 1849. Gould conceded Latham's name was valid and hence had precedence, and E. notatus was reduced to synonymy. Australian ornithologist Gregory Mathews argued that Latham's description mentioned black axillaries and hence must have referred to the letter-winged kite, and that Watling's drawings were inconclusive. He promoted the use of E. notatus over E. axillaris in 1916. This was followed for many years. But in 1980 Australian taxonomists Richard Schodde and Ian J. Mason refuted Mathews' claim that the original description of E. axillaris was ambiguous and reinstated the name. This has been followed by subsequent authorities. The black-shouldered kite has no recognised subspecies.<p>"Black-shouldered kite" has been designated the official English name by the International Ornithologists' Union (IOC). It has also been called the Australian black-shouldered kite to distinguish it from the Eurasian black-winged kite (E. caeruleus) and American white-tailed kite (E. leucurus)—both formerly known as "black-shouldered kite". Watling had recorded the Dharug term Geo-ga-rack.<p>In 1959, American ornithologist Kenneth C. Parkes noted that the plumage of the black-shouldered kite is similar to that of the black-winged and white-tailed kites, and proposed that all three were subspecies of a single cosmopolitan species E. caeruleus—much like the peregrine falcon (Falco peregrinus). Researchers William S. Clark and Richard C. Banks disputed this, pointing out the differences in anatomical proportions such as wing shape and tail length, and hunting behavior (E. caeruleus rarely hunts by hovering, unlike the other two species) and proposed the species be separated again in 1992. They are regarded as distinct in the IOC World Bird List.<p>Molecular evidence shows that the black-shouldered kite and its relatives belong to a subfamily Elaninae that is an early offshoot within the raptor family Accipitridae. There is some evidence they are more divergent from other raptors and better placed in their own family.

Scientific name

Elanus axillaris

Authority

(Latham, 1801)

Order

Accipitriformes

Family

Accipitridae

Genus

Elanus

Range and habitat

Black-shouldered kites may be sedentary or nomadic and are generally found in open grasslands or valleys where there are scattered clumps of trees, where the grass or groundcover is accessible from the air and ranges from 30 cm to 1.5 m (1–5 ft) high. As well as native grasslands they forage over pastures, cereal or vegetable crops and vineyards, often focusing on areas that have been recently harvested or ploughed and hence rendering prey more exposed. In urban areas, they are encountered on the edge of towns on wasteland, irregularly mown areas, sports fields, golf courses or grassy roadside verges. They also hunt over coastal dunes and drier marshland, but avoid areas with dense cover such as forest as well as bare or rocky ground.<p>Their numbers fluctuate during drought and floods and can be irruptive in response to sudden increases in mouse populations. The most distant banding recovery was from the Red Banks area in South Australia to Lithgow in eastern New South Wales three and a half years later, a distance of 1,073 km (667 mi).<p>Although reported throughout Australia, they are most common in the relatively fertile south-east and south-west corners of the mainland, and in south-east Queensland. They are rare in the deep desert and dryer areas such as western Cape York or the Northern Territory, and are occasional visitors to northern Tasmania, King Island, and the Torres Strait islands.

Migration

Nomadic

Behavior

Migration pattern: Nomadic.

Conservation

Population trend: rising.

Population trend

rising