| Little eagle | |
|---|---|
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| In flight | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Accipitriformes |
| Family: | Accipitridae |
| Genus: | Hieraaetus |
| Species: | H. morphnoides |
| Binomial name | |
| Hieraaetus morphnoides (Gould, 1841) | |
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| Little eagle range in red (pygmy eagle range in green) | |
| Synonyms | |
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The little eagle (Hieraaetus morphnoides) is a very small eagle endemic to Australia.
John Gould described the little eagle in 1841. The distinctive pygmy eagle has long been considered a subspecies, but a 2009 genetic study shows it to be distinctive genetically and warrants species status. [3] It is a near relative of both the Palearctic booted eagle and the massive but now extinct Haast's eagle of New Zealand. [4] [5] [6]
The little eagle is a medium-sized bird of prey, measuring 45–55 cm (17–21.5 inches) in length and weighing 815 g (1.8 lb), roughly the size of a peregrine falcon. [7] It has fully feathered legs and a square-cut, barred tail. Wingspan is about 120 cm with males having longer wings in proportion to their bodies, but being nearly half the weight of females. It is a powerful bird and during flight has strong wing beats, glides on flat wings and soars on slightly raised or flat wings. [8] [9] [10]
The little eagle occurs in light and dark colour forms and generally these colours change with age. The most common is the light form which is dark brown occurring on the back and wings with black streaks on the head and neck, and a sandy to pale under body. The dark form of this eagle is similar except the head and under body is usually darker brown or rich rufous. The sexes are similar with females being larger and typically darker. Juveniles are similar to adults but tend to be more strongly rufous in colour with less contrast in patterns. [8] [9] [10] [11]
Although the little eagle has a large range and can be found in most parts of Australia, except heavily forested parts of the Great Dividing Range. [11] It tends to inhabit open woodland, grassland and arid regions, shunning dense forest. Like so many Australian natives, it faces a deteriorating population due to a loss of habitat and competition from other species. One of the biggest factors to the decline of the little eagle is the decline of rabbits due to the release of the calicivirus, the eagle relied heavily on the rabbit population due to the extinction and massive decline of native terrestrial mammals of rabbit size or smaller such as large rodents, bandicoots, bettongs, juvenile banded hare-wallaby and other wallabies. [12]
In the first national bird atlas in 1977–81, the little eagle was reported in 65% of one degree grid cells across Australia, with mostly high reporting rates (more than 40% of surveys per grid) across New South Wales and Victoria. Breeding was recorded in 11% of cells, with the highest rates in New South Wales (NSW) and Victoria. [13] During the second national bird atlas in 1998–2002, the little eagle was recorded in 59% of grid cells, at mostly low reporting rates (recorded in less than 20% of surveys per grid). Breeding was recorded in 5% of grid cells. [7] [14] Overall, there has been a national decline in reporting rate of 14%. In NSW over the last 20 years (two little eagle generations) the decline in reporting rate has been 39%, and over the past 30 years has been 50%, with an accelerating trend since the 1990s. [15] The decline in reporting rate over the past 20 years for the South Eastern Highlands bioregion has been greater than 20%. [7] [14] This bioregion includes the ACT. [16]
The little eagle was once common in the ACT, but has undergone significant decline (greater than 70%) over the last 20 years. In the late 1980s there was an estimated 13 breeding pairs in the ACT, occurring mainly in the northern half of the ACT with the highest concentrations found in the Murrumbidgee and the Molonglo river corridors. [8] [17] By 2005 the only breeding record in the ACT was of an unsuccessful nest near Uriarra Crossing. [18] A more intensive ACT survey in 2007 found three breeding pairs, which fledged a total of four young. [19] In 2008 four breeding pairs were recorded and four young were fledged. [20] [21] In 2009, three breeding pairs were recorded with three young being fledged. [22]
Typical habitat for the little eagle includes woodland or open forest. Higher abundance of the species is associated with hillsides where there is a mixture of wooded and open areas such as riparian woodlands, forest margins and wooded farmland. Little eagles usually avoid large areas of dense forest, preferring to hunt in open woodland, where the birds use trees for lookouts. [9] [11] In the ACT, little eagles inhabit frequent open woodland and riparian areas. [8]
Little eagles nest in open woodland (usually on hillsides) and along tree-lined watercourses, with the nest typically placed in a mature, living tree. The birds build a stick nest lined with leaves and may use different nests in successive years, including those of other birds such as crows. A pair of little eagles will only reproduce once a year and each pair will only produce one or two eggs per season, usually laid in late August to early September. [11] After an incubation period of about 37 days, one or two young are fledged after approximately eight weeks. [23] [24] [8] Maturity in terms of breeding takes two to three years, leaving a large population of juvenile eagles, mature eagles constitute roughly less than three-quarters of the population. [9]
Little eagle nesting territories are defended against intruders and advertised by soaring, undulating flight display, conspicuous perching and/or calling. [23] [15] [11] Movement behaviour varies between individuals, and may be partly migratory (being an altitudinal migrant), dispersive or permanently resident. [11] They tend to slip away at the first sign of human intrusion. [9]
Little eagles hunt live prey and occasionally take carrion. The eagles search for prey by soaring, up to 500 m (1,600 ft) altitude, or by using an elevated exposed perch. The species is an agile, fast hunter swooping to take prey on the ground in the open but also from trees and shrubs. [23] [24] [11] [25] Recorded prey species (from feeding observations, nest remains and faecal pellets) show considerable variation indicating a broad diet, which seems to be determined primarily by the availability of prey of a suitable size. The little eagle would originally feed on small birds, mammals and reptiles and supplement its diet with large insects on occasion, however with the introduction of rabbits and foxes the little eagle's diet changed. Rabbits became widely abundant very quickly after being introduced, competing for habitat with native mammals. The introduction of foxes can also be attributed to the decline of the little eagle's main source of prey. The rabbit however is an ideal source of prey also, and so the rabbit population became the little eagle's main diet until the release of the calicivirus which decreased the rabbit population from between 65 and 85% in arid and semi-arid areas. [12] Their diet varies geographically; the diet in Northern Australia has a high proportion of birds, in the arid zone is mostly lizards, and in Southern Australia has a high proportion of juvenile rabbits. [10] In the ACT region its diet comprises mostly rabbits and to a lesser extent birds (especially rosellas, magpie-larks and starlings). [8] [22] [26]
There is some evidence of prey partitioning between little eagles and the sympatric, larger wedge-tailed eagle (Aquila audax), with the latter tending to take larger prey and to eat more carrion. [27] [26] However, rabbits are the most common dietary item for both eagle species near Canberra, indicating potential for competition for prey. Both species also eat carrion and it is possible that the more numerous wedge-tailed eagles in the Australian Capital Territory (ACT) region keep little eagles away from macropod carcasses, and that little eagles would eat more carrion if not excluded by wedge-tailed eagles. [27]
The little eagle was declared as 'Vulnerable' in the Australian Capital Territory under Section 38 of the Nature Conservation Act 1980. It was also listed as 'Vulnerable' in New South Wales (NSW) in Part 1 of Schedule 2 of the NSW Threatened Species Conservation Act 1995 and Gazetted[ clarification needed ] on 12 February 2012.
The little eagle is listed on the IUCN Red List as of least concern. [1] Reasons for it being classified as 'least concern' are that the bird of prey has a huge range, spanning up to 20,000km2 and the population size is only decreasing at a rate of 10% per ten years or 3 generations, instead of the required 30%. [1] The Red List amended the status of the little eagle from "Not Recognized" in 2006 to "Least Concern". [1] Also, the NSW Scientific Committee has made the determination to list the little eagle as a Vulnerable species under the Vulnerable species listing. The reasons for this listing is the reduction of habitat quality or diversity and genetic diversity.
The main threats to the species are the destruction and degradation of its foraging and breeding habitat causing it to come into competition with the larger and more dominant wedge-tailed eagle. [18] The wedge-tailed eagle is not necessarily a predator of the little eagle but the two species share common habitat and prey and the large size and dominant nature of the wedge-tailed eagle could mean that the little eagle would be forced out of hunting and breeding grounds or even killed and eaten.
Eagle is the common name for the golden eagle, bald eagle, and other birds of prey in the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. True eagles comprise the genus Aquila. Most of the 68 species of eagles are from Eurasia and Africa. Outside this area, just 14 species can be found—two in North America, nine in Central and South America, and three in Australia.
The wedge-tailed eagle is the largest bird of prey in the continent of Australia. It is also found in southern New Guinea to the north and is distributed as far south as the state of Tasmania. Adults of the species have long, broad wings, fully feathered legs, an unmistakable wedge-shaped tail, an elongated upper mandible, a strong beak and powerful feet. The wedge-tailed eagle is one of 12 species of large, predominantly dark-coloured booted eagles in the genus Aquila found worldwide. Genetic research has clearly indicated that the wedge-tailed eagle is fairly closely related to other, generally large members of the Aquila genus. A large brown-to-black bird of prey, it has a maximum reported wingspan of 2.84 m and a length of up to 1.06 m.
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 Haliaeetinae species. Like many raptors, the female is 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 Australian raven is a passerine bird in the genus Corvus native to much of southern and northeastern Australia. Measuring 46–53 centimetres (18–21 in) in length, it has all-black plumage, beak and mouth, as well as strong grey-black legs and feet. The upperparts are glossy, with a purple, blue, or green sheen, and its black feathers have grey bases. The Australian raven is distinguished from the Australian crow species by its throat hackles, which are prominent in adult birds. Older adult individuals have white irises, younger adults have white irises with an inner blue rim, while younger birds have dark brown irises until fifteen months of age, and hazel irises with an inner blue rim around each pupil until age two years and ten months. Nicholas Aylward Vigors and Thomas Horsfield described the Australian raven in 1827, its species name (coronoides) highlighting its similarity with the carrion crow. Two subspecies are recognized, which differ slightly in calls and are quite divergent genetically.
The black-shouldered kite, also known as the Australian black-shouldered kite, is a small raptor found in open habitats 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 booted eagle is a medium-sized mostly migratory bird of prey with a wide distribution in the Palearctic and southern Asia, wintering in the tropics of Africa and Asia, with a small, disjunct breeding population in south-western Africa. Like all eagles, it belongs to the family Accipitridae.
The African hawk-eagle is a large bird of prey. Like all eagles, it belongs to the family Accipitridae. This species’ feathered legs mark it as a member of the Aquilinae subfamily. The African hawk-eagle breeds in tropical Sub-Saharan Africa. It is a bird of assorted woodland, including both savanna and hilly areas but the tend to occur in woodland that is typically dry. The species tends to be rare in areas where their preferred habitat type is absent. This species builds a stick nest of around 1 m (3.3 ft) across in a large tree. The clutch is generally one or two eggs. The African hawk-eagle is powerfully built and hunts small to medium sized mammals and birds predominantly, occasionally taking reptiles and other prey as well. The call is a shrill kluu-kluu-kluu. The African hawk-eagle is considered a fairly stable species and a species of Least Concern per the IUCN.
Bonelli's eagle is a large bird of prey. The common name of the bird commemorates the Italian ornithologist and collector Franco Andrea Bonelli. Bonelli is credited with gathering the type specimen, most likely from an exploration of Sardinia. Some antiquated texts also refer to this species as the crestless hawk-eagle. Like all eagles, Bonelli's eagle belongs to the family Accipitridae. Its feathered legs marked it as member of the Aquilinae or booted eagle subfamily. This species breeds from Southern Europe, Africa on the montane perimeter of the Sahara Desert and across the Indian Subcontinent to Indonesia. In Eurasia, this species may be found as far west as Portugal and as far east as southeastern China and Thailand. It is usually a resident breeder. Bonelli's eagle is often found in hilly or mountainous habitats, with rocky walls or crags, from sea level to 1,500 m (4,900 ft). Habitats are often open to wooded land and can occur in arid to semi-moist climate. This eagle, though it can be considered partially opportunistic, is something of a specialist predator of certain birds and mammals, especially rabbits, galliforms and pigeons. On evidence, when staple prey populations decline or are locally scarce, Bonelli's eagle switch to being an opportunistic predator of a wide variety of birds. Despite its persistence over a large range and its continued classification as a least concern species by the IUCN, Bonelli's eagle has declined precipitously in various parts of its range, including almost all of its European distribution, and may face potential local extinction. The species' declines are due to widespread habitat destruction, electrocution from electricity pylons as well as persistent persecution.
Verreaux's eagle is a large, mostly African, bird of prey. It is also called the black eagle, especially in southern Africa, not to be confused with the black eagle of south and southeast Asia. The Verreaux's eagle lives in hilly and mountainous regions of southern and eastern Africa, and very locally in the Middle East.
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 barking owl, also known as the winking owl, is a nocturnal bird species native to mainland Australia and parts of New Guinea and the Moluccas. They are a medium-sized brown owl and have a characteristic voice with calls ranging from a barking dog noise to an intense human-like howl.
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 predominantly 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 powerful owl, a species of owl native to south-eastern and eastern Australia, is the largest owl on the continent. It is found in coastal areas and in the Great Dividing Range, rarely more than 200 km (120 mi) inland. The IUCN Red List of Threatened Species also refers to this species as the powerful boobook.
The Papuan eagle is a large bird of prey. It is also known by several other names, including Papuan harpy eagle, New Guinea eagle, New Guinea harpy eagle, or kapul eagle, the latter name from the local name for a usually arboreal, marsupial that the eagle is known to regularly hunt. This is an endemic species to New Guinea, and it can occasionally be found throughout the island. This is a forest-dwelling species, usually occurring in mature rainforest. The Papuan eagle is a fairly little-known species for a large eagle; however, it is known to prey on a wide range of prey, probably by and large mammals and birds from small to quite large sizes. What little study has been conducted about their breeding habits suggests they nest in a large forest tree, perhaps every other year. The Papuan eagle is probably naturally scarce, but it is under the threat of habitat destruction by deforestation, as well as hunting. Due to its small and declining population, the species has been classified as vulnerable by the IUCN.
The Tasmanian wedge-tailed eagle is an endangered bird of Tasmania. It is a subspecies of the more common wedge-tailed eagle.
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 spotted harrier also known as the smoke hawk, is a large Australasian bird of prey belonging to the family Accipitridae.
The genus Hieraaetus, sometimes known as small eagles or hawk-eagles, denotes a group of smallish eagles usually placed in the accipitrid subfamilies Buteoninae or Aquilinae.
The Aquilinae are a subfamily of eagles of the family Accipitridae. The general common name used for members of this subfamily is "booted eagle", although this is also the common name of a member of the subfamily. At one point, this subfamily was considered inclusive with the Buteoninae based probably on some shared morphological characteristics. However, research on the DNA of the booted eagles has shown that they are a monophyletic group that probably have had millions of years of separation from other extant forms of accipitrid.
