|Range of the letter-winged kite (2007)|
The letter-winged kite (Elanus scriptus) is a small, rare and irruptive bird of prey that is found only in Australia. Measuring around 35 cm (14 in) in length with a wingspan of 84–100 cm (33–39 in), the adult letter-winged kite has predominantly pale grey and white plumage and prominent black rings around its red eyes. It gains its name from the highly distinctive black underwing pattern of a shallow 'M' or 'W' shape, seen when in flight. This distinguishes it from the otherwise similar black-shouldered kite.
Irruptive growth, sometimes called Malthusian growth, is a growth pattern over time, defined by population explosions and subsequent sharp population crashes, or diebacks. It is an extension of the Malthusian growth model, specifically the growth pattern that causes a Malthusian catastrophe, and can occur when populations overshoot their carrying capacity, a phenomenon typically associated with r-strategists.
Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, which applies to species that are restricted to a defined geographical area.
The black-shouldered kite, 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 begins breeding in response to rodent outbreaks, with pairs nesting in loose colonies of up to 50 birds each. Three to four eggs are laid and incubated for around thirty days, though the eggs may be abandoned if the food source disappears. Chicks are fledged within five weeks of hatching. Roosting in well-foliaged trees during the day, the letter-winged kite hunts mostly at night. It is a specialist predator of rodents, which it hunts by hovering in mid-air above grasslands and fields. It is rated as near threatened on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species.
Rodents are mammals of the order Rodentia, which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents ; they are found in vast numbers on all continents except Antarctica. They are the most diversified mammalian order and live in a variety of terrestrial habitats, including human-made environments.
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable condition in the nest, the nestling and fledging stage can be the same. For precocial birds, those that develop and leave the nest quickly, a short nestling stage precedes a longer fledging stage.
A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status. The IUCN notes the importance of re-evaluating near-threatened taxon at appropriate intervals.
The letter-winged kite was described by ornithologist John Gould in 1842 under its current binomial name Elanus scriptus.The specific epithet is from the Latin word scriptum, meaning "written" or "marked". British explorer Charles Sturt wrote of seeing them on his travels in his 1849 book Narrative of an Expedition into Central Australia. The letter-winged kite is monotypic: no subspecies are recognised, nor is there any recorded geographic variation. Molecular evidence shows that the letter-winged kite and its relatives belong to the subfamily Elaninae, an early offshoot within the raptor family Accipitridae. There is some evidence that they may be more divergent from other raptors and better placed in their own family.
A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously or are related. The species description often contains photographs or other illustrations of the type material and states in which museums it has been deposited. The publication in which the species is described gives the new species a formal scientific name. Some 1.9 million species have been identified and described, out of some 8.7 million that may actually exist. Millions more have become extinct.
John Gould FRS was an English ornithologist and bird artist. He published a number of monographs on birds, illustrated by plates that he produced with the assistance of his wife, Elizabeth Gould, and several other artists including Edward Lear, Henry Constantine Richter, Joseph Wolf and William Matthew Hart. He has been considered the father of bird study in Australia and the Gould League in Australia is 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. Gould's work is referenced in Charles Darwin's book, On the Origin of Species.
Binomial nomenclature, also called binominal nomenclature or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomial name, a binomen, binominal name or a scientific name; more informally it is also called a Latin name.
"Letter-winged kite" has been designated the official name by the International Ornithologists' Union (IOC),derived from the letter-like markings under the wings. In Central Australia, southwest of Alice Springs, the Pitjantjatjara name for the letter-winged kite is nyanyitjira. It has been incorrectly called white-breasted sparrowhawk.
The International Ornithologists' Union, formerly known as the International Ornithological Committee, is a group of about 200 international ornithologists, and is responsible for the International Ornithological Congress and other international ornithological activities, undertaken by its standing committees.
Central Australia, also known as the Alice Springs Region, is one of the five regions in the Northern Territory of Australia. The term Central Australia is used to describe an area centred on Alice Springs. It is sometimes referred to as Centralia; likewise the people of the area are sometimes called Centralians. The region is located in the southern part of the Northern Territory spanning from the west on the Western Australian Border to the east on the Queensland border.
Alice Springs is the third-largest town in the Northern Territory of Australia. Known as Stuart until 31 August 1933, the name Alice Springs was given by surveyor William Whitfield Mills after Alice, Lady Todd, wife of the telegraph pioneer Sir Charles Todd. Now colloquially known as The Alice or simply Alice, the town is situated roughly in Australia's geographic centre. It is nearly equidistant from Adelaide and Darwin.
The adult letter-winged kite is about 35 cm (14 in) in length, with a wingspan between 84 and 100 cm (33 and 39 in). The female is slightly heavier, averaging 310 g (11 oz) compared to the male's average weight of 260 g (9.2 oz). The sexes have similar plumage. The adult male has pale grey upperparts, wings and nape with a white head and white underparts. It has large deep-red eyes, which are surrounded by a black eye patch. Its bill is black, with a dark grey-brown cere at its base. Its wings are marked with a black shoulder patch above and a striking black line underneath, which runs from the primary coverts to the body, and which resembles a letter 'M' or 'W' when flying. The central rectrices of the tail are pale grey, while the rest of the tail feathers are white. The legs and feet are a fleshy pinkish white or white. The feet have three toes facing forwards and one toe facing backwards. The female is similar but can be distinguished by a greyer crown, and its grey plumage is slightly darker all over. Moulting has been recorded from all months except May and August, and is probably related to breeding.
A covert feather or tectrix on a bird is one of a set of feathers, called coverts, which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail.
In biology, moulting, or molting, also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body, either at specific times of the year, or at specific points in its life cycle.
The juvenile has a white lower forehead, face, chin and throat, with a brownish orange band across the forehead, neck and breast. It has a similar dark eye patch to the adult, and the eyes themselves are dark brown. The hindneck is grey-brown, and the upperpart feathers are grey-brown with orange tips. The rump and central tail rectrices are pale grey tipped with orange. The bill is black with a brownish grey cere.
The letter-winged kite soars with v-shaped upcurved wings, the primaries slightly spread and the tail fanned, giving it a square appearance. When flying actively, it beats its wings more slowly and deeply than the black-shouldered kite (Elanus axillaris). The wing beats are interspersed with long glides on angled wings. It can also hover motionless facing into the wind and flapping its wings.The 'M' or 'W' on the underside of its wing and lack of black wing tips help distinguish it from the black-shouldered kite. Additionally, the latter species is diurnal, not nocturnal. At night, the letter-winged kite could be mistaken for the eastern barn owl (Tyto javanica) or eastern grass owl (T. longimembris), but these species have large heads; longer and trailing legs; blunted wings; and stockier bodies. The grey falcon (Falco hypoleucos) has somewhat similar colouration to the letter-winged kite but is bulkier and heavier overall, and lacks the black markings.
The letter-winged kite is generally silent when alone but often noisy when breeding or roosting communally at night, beginning to call at the rising of the moon.Its calls have been described as chicken-like chirping or a repeated loud kacking, and at times resemble those of the barn owl or black-shouldered kite. A rasping call, or scrape, composed of six or seven half-second long notes is the main contact call between a pair. It is often used by the female in answer to a whistle by her mate, when a bird alights at the nest, or—loudly—in response to an intruder. The male can utter a loud whistle in flight, which can serve as an alarm call. Mated pairs chatter to one another at night in the colony.
The usual habitat of the letter-winged kite is arid and semi-arid open, shrubby or grassy country, across the arid interior of the continent, particularly the southern Northern Territory, particularly the Barkly Tableland, and northeastern South Australia, and Queensland, where it is relatively common in western areas south of 20° south, and has been recorded as far afield as Townsville and Stradbroke Island. In South Australia it may reach the Eyre Peninsula and southeastern corner on occasion. The species is generally rare in New South Wales:it has been recorded in the vicinity of Broken Hill in the far west, and twice in Inverell in the north of the state—once found dead in a street in 1965 and once spotted alive a year later. It is rare in Western Australia.
Its abundance or even presence in any given area is heavily dependent on availability of food; spells of significant rainfall inland lead to surges in rodent numbers, which in turn lead to irruptions of letter-winged kites.Nesting and raising multiple broods in succession, the kite population may increase ten-fold. Major irruptions have taken place in 1951–53, 1969–70, 1976–77, and 1993–95. Eventually dry conditions lead to a fall in rodent numbers and dispersal of birds, which often starve if they fail to find prey elsewhere.
The letter-winged kite typically hunts at night, with daytime foraging taking place in areas of superabundant or scarce prey.By day, birds roost in leafy trees with plenty of cover, in colonies of up to 400 individuals, becoming active at dusk. Their social behaviour is poorly known on account of their nocturnal habits and shy nature, being difficult to approach when roosting.
Within its range, the letter-winged kite generally breeds in an area covering the Diamantina and Lake Eyre drainage basins, Sturt Stony Desert, eastern Simpson Desert and Barkly Tableland, to Richmond, Queensland, and Banka Banka Station in the north and Boolkarie Creek, South Australia, in the south. Nesting has also been recorded in Exmouth Gulf and southwest Western Australia, the southwest of the Northern Territory, and the Clarence River district and northwest of New South Wales.The birds nest in colonies of up to 50 pairs, and have more than one nest and brood at once. At times their nests are close to those of spotted harriers (Circus assimilis), black kites (Milvus migrans), whistling kites (Haliastur sphenurus), brown falcons (Falco berigora) and black falcons (Falco subniger).
It is not known if breeding pairs remain bonded after breeding.Aerial courtship displays involve mutual flight high above the nest, with the male flying much higher than the female and holding its wings high with rapidly fluttering wingtips. He drops near its mate, who responds by holding her wings in a similar manner. The two then chatter while circling each other. Copulation often follows.
There does not appear to be a set breeding season; instead, the species forms nesting colonies in response to rodent irruptions. Birds produce broods for as long as the rodents are abundant, and stop when their food source declines. metres (15 ft) or higher off the ground. On average it is about 50 cm (20 in) wide and 34 cm (13 in) high, with a 20 cm (8 in) diameter cup-shaped depression within. It is lined with green leaves and other material such as regurgitated pellets.Often smaller trees are chosen as nesting sites over larger ones, with some preference given to the beefwood ( Grevillea striata ). Other species used include waddy ( Acacia peuce ), coolibah ( Eucalyptus microtheca ) and sheoaks ( Casuarina spp.). Generally there is one nest per tree, though there may be multiple nests in single trees when rodent irruptions provide an abundance of food. The nest is a large, untidy and shallow cup of sticks, usually located in the foliage near the top of trees, some five
The clutch consists of three to four, or rarely five or even six, dull white eggs measuring on average 44 mm × 32 mm (1.7 in × 1.3 in) with red-brown blotches and tapered oval in shape. The markings are often heavier around the larger end of the egg. The female incubates the eggs for 30 days, though this has been difficult to confirm due to unpredictable breeding. The young are born semi-altricial, covered in white down with black beaks and feet and dark brown eyes. By a week old, they have pale tan down on their back and brown eyes. They are fully feathered by 3–4 weeks of age and can fly at 7 weeks. During this time they are brooded by the female, while the male brings food at night. He calls on his approach, at which the female flies out to receive the food and then convey it to the young. Though not known to feed the young himself, the male may at times bring food to the female on the nest. As the brood grows, the female joins the male in catching food; she may eventually begin a second brood and leave the male to feed the older brood. Nestlings fledge at around 32 days, although have been known to be abandoned if the food supply suddenly disappears. Birds in juvenile plumage reach sexual maturity within their first year of age.
The letter-winged kite hunts mainly in the first two hours after sunset. It flies at a height of 10 to 20 m (35 to 65 ft), moving in wide circles scanning the ground, then hovers at a height of up to 30 m (100 ft). When prey is spotted, the kite drops silently onto it, feet-first with wings raised high.
The letter-winged kite's principal prey is the long-haired rat (Rattus villosissimus). When population numbers of this rodent build up, following significant rainfall, the kites are able to breed continuously and colonially so that their numbers increase in parallel.One Central Australian study over two and a half years found that, within six months of an outbreak starting, the birds had relocated to that location. When the rodent populations decline, the now superabundant kites may disperse and appear in coastal areas far from their normal range; though they may occasionally breed in these new locations, they do not persist and eventually disappear.
Across Central Australia, the letter-winged kite shares its habitat with another nocturnal rodent hunter, the eastern barn owl; the latter species prefers larger rodents such as the plains rat (Pseudomys australis), whereas the kite hunts all species, including the sandy inland mouse (Pseudomys hermannsburgensis) and spinifex hopping mouse (Notomys alexis), on availability. ), beetles and spur‐throated locust (Nomadacris guttulosa).Other predators sharing its habitat and prey include the dingo, feral cat and fox. Overall, letter-winged kites average one rodent consumed per day. They have also been recorded hunting the introduced house mouse (Mus musculus) in north-eastern South Australia. Other animals recorded as prey include rabbit, fat-tailed dunnart (Sminthopsis crassicaudata), stripe-faced dunnart (Sminthopsis macroura), Forrest's mouse (Leggadina forresti
Black falcons have been reported hunting adult letter-winged kites, while black kites have taken nestlings.
The letter-winged kite's fluctuations in abundance make its conservation status difficult to assess,though it is clearly much less common than the black-shouldered kite. It also rarely comes into contact with people across most of its range. It is rated as near threatened on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, as its population may number as low as 1,000 individuals between irruptions. It is unknown to what extent competition for food with the introduced red fox or feral cat, or if habitat degraded by overgrazing, have an impact on the letter-winged kite. It is not known whether the population has increased or decreased overall since European settlement.
The common buzzard is a medium-to-large bird of prey which has a large range. A member of the genus Buteo, it is a member of the family Accipitridae. The species lives in most of Europe and extends its range into Asia, mainly western Russia. Over much of its range, it is a year-round resident. However, buzzards from the colder parts of the Northern Hemisphere as well as those that breed in the eastern part of their range typically migrate south for the northern winter, many culminating their journey as far as South Africa. The common buzzard is an opportunistic predator that can take a wide variety of prey, but it feeds mostly on small mammals, especially rodents such as voles. It typically hunts from a perch. Like most accipitrid birds of prey, it builds a nest, typically in trees in this species, and is a devoted parent to a relatively small brood of young. The common buzzard appears to be the most common diurnal raptor in Europe, as estimates of its total global population run well into the millions.
The Accipitridae, one of the four families within the order Accipitriformes, are a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-sized mammals, with a number feeding on carrion and a few feeding on fruit. The Accipitridae have a cosmopolitan distribution, being found on all the world's continents and a number of oceanic island groups. Some species are migratory.
Kite is the common name for certain birds of prey in the family Accipitridae, particularly in subfamilies Milvinae, Elaninae, and Perninae.
The black-winged kite, also known as the black-shouldered kite, is a small diurnal bird of prey in the family Accipitridae best known for its habit of hovering over open grasslands in the manner of the much smaller kestrels. This Eurasian and African species was sometimes combined with the Australian black-shouldered kite and the white-tailed kite of North and South America which together form a superspecies. This kite is distinctive, with long wings; white, grey and black plumage; and owl-like forward-facing eyes with red irises. The owl-like behaviour is even more pronounced in the letter-winged kite, a nocturnal relative in Australia. Although mainly seen on plains, they are sometimes seen on grassy slopes of hills in the higher elevation regions of Asia. They are not migratory, but show nomadism in response to weather and food availability. They are well adapted to utilize periodic upsurges in rodent populations and can raise multiple broods in a single year unlike most birds of prey. Populations in southern Europe have grown in response to human activities, particularly agriculture and livestock rearing.
The white-bellied sea eagle, also known as the white-breasted sea eagle, is a large diurnal bird of prey in the family Accipitridae. Originally described by Johann Friedrich Gmelin in 1788, it is closely related to Sanford's sea eagle of the Solomon Islands, and the two are considered a superspecies. A distinctive bird, the adult white-bellied sea eagle has a white head, breast, under-wing coverts and tail. The upper parts are grey and the black under-wing flight feathers contrast with the white coverts. The tail is short and wedge-shaped as in all Haliaeetus species. Like many raptors, the female is slightly larger than the male, and can measure up to 90 cm (35 in) long with a wingspan of up to 2.2 m (7.2 ft), and weigh 4.5 kg (9.9 lb). Immature birds have brown plumage, which is gradually replaced by white until the age of five or six years. The call is a loud goose-like honking.
The long-eared owl, also known as the northern long-eared owl or, more informally, as the lesser horned owl or cat owl, is a medium-sized species of owl with an extensive breeding range. The scientific name is from Latin. The genus name Asio is a type of eared owl, and otus also refers to a small, eared owl. The species breeds in many areas through Europe and Asia, as well as in North America. This species is a part of the larger grouping of owls known as typical owls, of the family Strigidae, which contains most extant species of owl.
The nankeen kestrel is a raptor native to Australia and New Guinea. It is one of the smallest falcons, and unlike many, does not rely on speed to catch its prey. Instead, it simply perches in an exposed position, but it also has a distinctive technique of hovering over crop and grasslands.
Elanus is a genus of bird of prey in the elanine kite subfamily. It was introduced by the French zoologist Jules-César Savigny in 1809 with the black-winged kite as the type species. The name is from the Ancient Greek elanos for a "kite".
The lizard buzzard or lizard hawk is a bird of prey in the family Accipitridae. It is native to Sub-Saharan Africa. Despite its name, it may be more closely related to the Accipiter hawks than the Buteo buzzards.
The masked booby, also called the masked gannet or the blue-faced booby, is a large seabird of the booby and gannet family, Sulidae. First described by the French naturalist René-Primevère Lesson in 1831, the masked booby is one of six species of booby in the genus Sula. It has a typical sulid body shape, with a long pointed yellowish bill, long neck, aerodynamic body, long slender wings and pointed tail. The adult is bright white with black wings, a black tail and a dark face mask; at 75–85 cm (30–33 in) long, it is the largest species of booby. The sexes have similar plumage. This species ranges across tropical oceans, except in the eastern Atlantic and eastern Pacific. In the latter, it is replaced by the Nazca booby, which was formerly regarded as a subspecies of masked booby.
The square-tailed kite is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as kites, eagles and harriers.
The black falcon is a medium-large falcon that is endemic to Australia. It can be found in all mainland states and territories and yet is regarded as Australia's most under-studied falcon.
The Australian hobby, also known as the little falcon, is one of six Australian members of the family Falconidae. This predominately diurnal bird of prey derives its name ‘longipennis’ from its long primary wing feathers. It occurs throughout Australia and other neighbouring countries with migrating individuals found on the islands of Indonesia and New Guinea
The little eagle is a very small eagle native to Australia, measuring 45–55 cm in length and weighing 815 g (1.8 lb), roughly the size of a peregrine falcon. It tends to inhabit open woodland, grassland and arid regions, shunning dense forest. It is a near relative of both the Palearctic booted eagle and the massive but now extinct Haast's eagle of New Zealand.
The white-necked heron or Pacific heron is a species of heron that is found on most of the Australian continent wherever freshwater habitats exist. It is also found in parts of Indonesia, New Guinea and New Zealand, but is uncommon in Tasmania. The populations of this species in Australia are known to be nomadic like most water birds in Australia, moving from one water source to another often entering habitats they have not previously occupied, taking advantage of flooding and heavy rain where the surplus of food allows them to breed and raise their young. Population explosions have been known when the environmental conditions are right for this species in places where they have been rare or unknown.
The black-breasted buzzard is a large raptor endemic to mainland Australia. First described by John Gould in 1841, it forms part of the family Accipitridae and is most closely related to the square-tailed kite. It is a versatile hunter known for its special skill in cracking eggs. The species is common throughout most of its range.
The grey falcon is a medium-sized falcon native to Australia, possibly the rarest. It is uncommon throughout its range and currently classified as Vulnerable.
The red-capped robin is a small passerine bird native to Australia. Found in drier regions across much of the continent, it inhabits scrub and open woodland. Like many brightly coloured robins of the family Petroicidae, it is sexually dimorphic. Measuring 10.5–12.5 cm (4.1–4.9 in) in length, the robin has a small thin black bill, and dark brown eyes and legs. The male has a distinctive red cap and red breast, black upperparts, and a black tail with white tips. The underparts and shoulders are white. The female is an undistinguished grey-brown. This species uses a variety of songs, and males generally sing to advertise territories and attract females. Birds are encountered in pairs or small groups, but the social behaviour has been little studied.
The scissor-tailed kite, also known as African swallow-tailed kite or fork-tailed kite is a bird of prey in the monotypic genus Chelictinia in the family Accipitridae. It is widespread in the northern tropics of Africa.
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