Black-shouldered kite

Black-shouldered kite
Elanus axillaris -Royal Botanic Gardens, Cranbourne, Melbourne, Victoria, Australia-8.jpg
At Royal Botanic Gardens, Cranbourne, Melbourne, Victoria, Australia
Scientific classification edit
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Accipitriformes
Family:Accipitridae
Genus:Elanus
Species:
E. axillaris
Binomial name
Elanus axillaris
(Latham, 1801)
Elanus axillaris distribution.svg
Range of black-shouldered kite

The black-shouldered kite (Elanus axillaris), also known as the Australian black-shouldered kite, is a small raptor found in open habitat throughout Australia. It resembles similar species found in Africa, Eurasia and North America, including the black-winged kite, a species that has in the past also been called "black-shouldered kite". Measuring around 35 cm (14 in) in length with a wingspan of 80–100 cm (31–39 in), the adult black-shouldered kite has predominantly grey-white plumage and prominent black markings above its red eyes. It gains its name from the black patches on its wings. The primary call is a clear whistle, uttered in flight and while hovering. It can be confused with the related letter-winged kite in Australia, which is distinguished by the striking black markings under its wings.

The species forms monogamous pairs, breeding between August and January. The birds engage in aerial courtship displays which involve high circling flight and ritualised feeding mid-air. Three or four eggs are laid and incubated for around thirty days. Chicks are fully fledged within five weeks of hatching and can hunt for mice within a week of leaving the nest. Juveniles disperse widely from the home territory. The black-shouldered kite hunts in open grasslands, searching for its prey by hovering and systematically scanning the ground. It mainly eats small rodents, particularly the introduced house mouse, and has benefitted from the modification of the Australian landscape by agriculture. It is rated as least concern on the International Union for Conservation of Nature (IUCN)'s Red List of "Endangered species."

Taxonomy

Illustration in John Gould's Birds of Australia, 1840s

The black-shouldered kite was first described by English ornithologist John Latham in 1801, as Falco axillaris.[2] Its specific name is derived from the Latin axilla, meaning "armpit",[3] relating to the dark patches under the wings.[4] He reported the description came from a bird that had been kept for two months in the early colony.[5] 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.[6]

English naturalist John Gould described the same species as Elanus notatus in 1838 from a specimen from New South Wales,[7] apparently unaware of Latham's description.[6] English zoologist George Robert Gray followed Latham using the binomial Elanus axillaris in 1849.[8] 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.[6] This was followed for many years.[9] 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.[10] This has been followed by subsequent authorities.[9][11] The black-shouldered kite is monotypic; no subspecies are recognised.[11]

"Black-shouldered kite" has been designated the official name by the International Ornithologists' Union (IOC).[11] 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".[4] Watling had recorded the Dharug term Geo-ga-rack.[6]

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).[12] 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.[13] They are regarded as distinct in the IOC World Bird List.[11]

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.[14][15] There is some evidence they are more divergent from other raptors and better placed in their own family.[16][17]

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