Letter-winged Kite
Encyclopedia
The Letter-winged Kite (Elanus scriptus) is a small, rare and irruptive
Australia
n raptor
with a core range in central Australia. The adult is a small and graceful, predominantly pale grey and white, raptor with black shoulders and red eyes. It is similar in appearance to the Black-shouldered Kite
except for a very distinctive black underwing pattern of a shallow ‘M’ shape, seen when in flight. Roosting during the day in well-foliaged trees and hunting at night, it is the world's only fully nocturnal raptor. Like all the elanid kite
s, it is a specialist predator of rodents, which it hunts by hovering in mid-air above grasslands and fields.
in 1842. Its specific name is Latin
scriptum meaning "written" or "marked". It is one of four species of small predominantly white-plumaged raptors in the genus Elanus
. A taxonomic proposal based on DNA studies has recommended classifying these kites as a separate family (Elanidae). A 2004 molecular study of cytochrome-b DNA sequences shows them to have split off from typical hawks and eagles at an earlier date than the Osprey
, which has been classically classified in its own family.
In Central Australia
, southwest of Alice Springs, the Pitjantjatjara term for the Letter-winged Kite is nyanyitjira.
(10.3 oz
), the adult Letter-winged Kite is a pale grey with a white head and white underparts. It bears a characteristic long black leading edge of the inner wing, which resembles a letter 'M' or 'W' when flying. When perched, this gives them their prominent black "shoulders". It has red eyes, with black eye patches surrounding. Their nostrils are yellow and the sharp hooked beaks are black. The legs and feet are also yellow, and the feet have three toes facing forwards and one toe facing backwards. The female can be distinguished by a greyer crown.
The 'M' or 'W' on the underside of its wing, and lack of black wing tips help distinguish it from the Black-shouldered Kite. In flight, it beats its wings more slowly and deeply. Finally, the latter species is diurnal, not nocturnal.
Its call is a chicken-like chirping or a repeated loud kacking.
open, shrubby
or grassy
country, across the arid interior of the continent, such as the Channel Country
and Gulf Country
of Western Queensland and into the Northern Territory. Its range may spread south with rodent plagues. The species has been recorded in the vicinity of Broken Hill
in far western New South Wales, and a dead bird recorded in a street in Inverell
in the north of the state in 1965 and another spotted there a year later, as well as Lake Eyre in northern South Australia.
, Rattus villosissimus. When population numbers of this rodent
build up, following good rainfall, the Kites are able to breed continuously and colonially so that their numbers increase in parallel. When the rodent populations decline, the now superabundant Kites may disperse and appear in coastal areas far from their normal range in which, though they may occasionally breed, they do not persist and eventually disappear. One central Australian study over two and a half years found the kites had relocated to an area within six months of a rodent outbreak starting.
Across Central Australia, it shares its habitat with another nocturnal rodent hunter, the Barn Owl (Tyto alba), with the latter species preferring larger rodents such as the Plains rat (Pseudomys australis
) whereas the kite took all species, including the Sandy Inland Mouse (Pseudomys hermannsburgensis) and Spinifex Hopping Mouse (Notomys alexis), on availability. Overall, Letter-winged Kites average one rodent consumed a day. Other predators sharing its habitat include the dingo, feral cat and fox.
Letter-winged Kites have also been recorded hunting the introduced house mouse Mus musculus in north-eastern South Australia.
Irruptive growth
Irruptive growth, sometimes called Malthusian growth, is a growth pattern defined by population explosions and subsequent sharp population crashes, or diebacks...
Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n raptor
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
with a core range in central Australia. The adult is a small and graceful, predominantly pale grey and white, raptor with black shoulders and red eyes. It is similar in appearance to the Black-shouldered Kite
Black-shouldered Kite
The Black-shouldered Kite or Australian Black-shouldered Kite is a small raptor found in open habitat throughout Australia and resembles similar species found in Eurasia and North America, which have in the past also been named as Black-shouldered Kites...
except for a very distinctive black underwing pattern of a shallow ‘M’ shape, seen when in flight. Roosting during the day in well-foliaged trees and hunting at night, it is the world's only fully nocturnal raptor. Like all the elanid kite
Elanid kite
An elanid kite, sometimes white-tailed kite, is any of several small, long-winged, hovering raptors. All are specialist rodent hunters and most are members of the genus Elanus. Some authorities list the group as a formal subfamily, Elaninae...
s, it is a specialist predator of rodents, which it hunts by hovering in mid-air above grasslands and fields.
Taxonomy
The Letter-winged Kite was originally described by ornithologist John GouldJohn Gould
John Gould was an English ornithologist and bird artist. The Gould League in Australia was named after him. His identification of the birds now nicknamed "Darwin's finches" played a role in the inception of Darwin's theory of evolution by natural selection...
in 1842. Its specific name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
scriptum meaning "written" or "marked". It is one of four species of small predominantly white-plumaged raptors in the genus Elanus
Elanus
Black-winged Kites is a genus of bird of prey in the elanid kite subfamily. It consists of four species.* Black-winged Kite, Elanus caeruleus* Black-shouldered Kite, Elanus axillaris* White-tailed Kite, Elanus leucurus...
. A taxonomic proposal based on DNA studies has recommended classifying these kites as a separate family (Elanidae). A 2004 molecular study of cytochrome-b DNA sequences shows them to have split off from typical hawks and eagles at an earlier date than the Osprey
Osprey
The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...
, which has been classically classified in its own family.
In Central Australia
Central Australia
Central Australia/Alice Springs Region is one of the five regions in the Northern Territory. The term Central Australia is used to describe an area centred on Alice Springs in Australia. It is sometimes referred to as Centralia; likewise the people of the area are sometimes called Centralians...
, southwest of Alice Springs, the Pitjantjatjara term for the Letter-winged Kite is nyanyitjira.
Description
Measuring 33 to 38 cm in length (13-15 in) with a wingspan of 85 to 95 cm (34–38 in), and weighing around 291 gGram
The gram is a metric system unit of mass....
(10.3 oz
Ounce
The ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 28 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
), the adult Letter-winged Kite is a pale grey with a white head and white underparts. It bears a characteristic long black leading edge of the inner wing, which resembles a letter 'M' or 'W' when flying. When perched, this gives them their prominent black "shoulders". It has red eyes, with black eye patches surrounding. Their nostrils are yellow and the sharp hooked beaks are black. The legs and feet are also yellow, and the feet have three toes facing forwards and one toe facing backwards. The female can be distinguished by a greyer crown.
The 'M' or 'W' on the underside of its wing, and lack of black wing tips help distinguish it from the Black-shouldered Kite. In flight, it beats its wings more slowly and deeply. Finally, the latter species is diurnal, not nocturnal.
Its call is a chicken-like chirping or a repeated loud kacking.
Distribution and habitat
The usual habitat of the Letter-winged Kite is semi-aridSemi-arid
A semi-arid climate or steppe climate describes climatic regions that receive precipitation below potential evapotranspiration, but not extremely...
open, shrubby
Shrubland
Shrubland, scrubland, scrub or brush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity...
or grassy
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
country, across the arid interior of the continent, such as the Channel Country
Channel Country
The Channel Country is region of outback Australia located mostly in the state of Queensland but also in portions of South Australia, Northern Territory and New South Wales. The name comes from the numerous intertwined rivulets that cross the region, which cover 150,000 km²...
and Gulf Country
Gulf Country
The Gulf Country is the name given to the region of woodland and savanna grassland surrounding the Gulf of Carpentaria in north western Queensland and eastern Northern Territory on the north coast of Australia...
of Western Queensland and into the Northern Territory. Its range may spread south with rodent plagues. The species has been recorded in the vicinity of Broken Hill
Broken Hill, New South Wales
-Geology:Broken Hill's massive orebody, which formed about 1,800 million years ago, has proved to be among the world's largest silver-lead-zinc mineral deposits. The orebody is shaped like a boomerang plunging into the earth at its ends and outcropping in the centre. The protruding tip of the...
in far western New South Wales, and a dead bird recorded in a street in Inverell
Inverell, New South Wales
Inverell is a town in northern New South Wales, Australia, situated on the Macintyre River. It is also the centre of Inverell Shire. Inverell is located on the Gwydir Highway on the western slopes of the Northern Tablelands. It has a temperate climate...
in the north of the state in 1965 and another spotted there a year later, as well as Lake Eyre in northern South Australia.
Food and feeding
The Letter-winged Kite is the only fully nocturnal raptor. Its principal prey is the Long-haired RatLong-Haired Rat
Rattus villosissimus, the Australian Long-haired Rat, is a species of rodent in the family Muridae. It is endemic to Australia, where its core range is "the Barkly lake system of the Barkly Tableland of the Northern Territory and the Channel Country in Southwest Queensland and north-eastern South...
, Rattus villosissimus. When population numbers of this rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
build up, following good rainfall, the Kites are able to breed continuously and colonially so that their numbers increase in parallel. When the rodent populations decline, the now superabundant Kites may disperse and appear in coastal areas far from their normal range in which, though they may occasionally breed, they do not persist and eventually disappear. One central Australian study over two and a half years found the kites had relocated to an area within six months of a rodent outbreak starting.
Across Central Australia, it shares its habitat with another nocturnal rodent hunter, the Barn Owl (Tyto alba), with the latter species preferring larger rodents such as the Plains rat (Pseudomys australis
Pseudomys australis
The Plains Rat, or Plains Mouse, or Eastern Mouse, or Palyoora , is a threatened rodent species native to Australia.-Captivity:...
) whereas the kite took all species, including the Sandy Inland Mouse (Pseudomys hermannsburgensis) and Spinifex Hopping Mouse (Notomys alexis), on availability. Overall, Letter-winged Kites average one rodent consumed a day. Other predators sharing its habitat include the dingo, feral cat and fox.
Letter-winged Kites have also been recorded hunting the introduced house mouse Mus musculus in north-eastern South Australia.