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The wedge-tailed eagle (''Aquila audax'') is the largest
bird of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...
in the continent of
Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
. It is also found in southern
New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torres ...
to the north and is distributed as far south as the state of
Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...
. Adults of this species have long, broad wings, fully feathered legs, an unmistakable wedge-shaped tail, an elongated maxilla, 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.Lerner, H., Christidis, L., Gamauf, A., Griffiths, C., Haring, E., Huddleston, C.J., Kabra, S., Kocum, A., Krosby, M., Kvaloy, K., Mindell, D., Rasmussen, P., Rov, N., Wadleigh, R., Wink, M. & Gjershaug, J.O. (2017). ''Phylogeny and new taxonomy of the Booted Eagles (Accipitriformes: Aquilinae)''. Zootaxa, 4216(4), 301–320. A large brown-to-black bird of prey, it has a maximum reported wingspan of and a length of up to . The wedge-tailed eagle is one of its native continent's most generalized birds of prey.Debus, S. (2017). ''Australasian Eagles and Eagle-like Birds''. CSIRO Publishing. They reside in most habitats present in Australia, ranging from
desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
and
semi-desert A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi ...
to
plains In geography, a plain is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and as plateaus or uplands. In ...
to mountainous areas to
forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...
, even sometimes
tropical rainforest Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equator ...
s. Preferred habitats, however, tend towards those that have a fairly varied topography including rocky areas, some
open terrain Open terrain, open country or open ground is terrain which is mostly flat and free of obstructions such as trees and buildings. Examples include farmland, grassland and specially cleared areas such as an airport. Such terrain is significant in ...
and native
woodlot A woodlot is a parcel of a woodland or forest capable of small-scale production of forest products (such as wood fuel, sap for maple syrup, sawlogs, and pulpwood) as well as recreational uses like bird watching, bushwalking, and wildflower appr ...
s such as ''
Eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as ...
'' stands.Olsen, P. (2005). ''Wedge-tailed Eagle''. Australian Natural History Series. CSIRO Publishing. The wedge-tailed eagle is one of the world's most powerful avian predators. Although a true generalist which hunts a wide range of prey, including
bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s,
reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...
s and, rarely, other taxa, this species is by and large a
mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...
predator.Olsen, J. (2014). ''Australian High Country Raptors''. CSIRO Publishing. The introduction of the
European rabbit The European rabbit (''Oryctolagus cuniculus'') or coney is a species of rabbit native to the Iberian Peninsula (including Spain, Portugal, and southwestern France), western France, and the northern Atlas Mountains in northwest Africa. It has b ...
(''Oryctolagus cuniculus'') has been a boon to the wedge-tailed eagle and they hunt these and other
invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...
in large volume, although the wedge-tailed eagle otherwise generally lives off of
marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in ...
s, including many surprisingly large
macropods Macropod may refer to: * Macropodidae, a marsupial family which includes kangaroos, wallabies, tree-kangaroos, pademelons, and several others * Macropodiformes, a marsupial suborder which includes kangaroos, wallabies and allies, bettongs, potoro ...
. Additionally, wedge-tailed eagles often eat not inconsiderable amounts of
carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
, especially while young.Brown, L, & Amadon, D. (1986) ''Eagles, Hawks and Falcons of the World''. The Wellfleet Press. . Wedge-tailed eagles tend to pair for several years, possibly mating for life. This species generally constructs a large stick nest in an ample tree, normally the largest in a stand, and lays typically two, although sometimes 1 to 4, eggs. Usually breeding efforts manage to produce one or two fledglings, which after a few months more tend to disperse widely. Nesting failures are usually attributable to human interference such as
logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. Logging is the beginning of a supply cha ...
activity and other alterations, which both degrade habitats and cause disturbances. This species is known to be highly sensitive to human disturbance at the nest, which may lead to abandonment of the young. Bekessy, S. A., Wintle, B. A., Gordon, A., Fox, J. C., Chisholm, R., Brown, B., Regan, T., Mooney, N., Read, S. & Burgman, M. A. (2009). ''Modelling human impacts on the Tasmanian wedge-tailed eagle (Aquila audax fleayi)''. Biological conservation, 142(11), 2438–2448. Although historically heavily
persecuted Persecution is the systematic mistreatment of an individual or group by another individual or group. The most common forms are religious persecution, racism, and political persecution, though there is naturally some overlap between these terms ...
by humans via
poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...
ings and
shooting Shooting is the act or process of discharging a projectile from a ranged weapon (such as a gun, bow, crossbow, slingshot, or blowpipe). Even the acts of launching flame, artillery, darts, harpoons, grenades, rockets, and guided missiles ...
s, mostly for alleged predation on
sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...
, wedge-tailed eagles have proved to be exceptionally resilient and have quickly rebounded to similar or even higher than pre-colonization numbers, thanks in part to humans inadvertently providing several food sources such as rabbits and large volumes of
roadkill Roadkill is an animal or animals that have been struck and killed by drivers of motor vehicles on highways. Wildlife-vehicle collisions (WVC) have increasingly been the topic of academic research to understand the causes, and how it can be ...
s.Knobel, J. (2015). ''The conservation status of the Wedge-tailed Eagle in Australian law and thoughts on the value of early legal intervention in the conservation of a species''. De Jure Law Journal, 48(2), 293–311.


Taxonomy

The species was first described by the English ornithologist John Latham in 1801 under the
binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...
''Vultur audax''. The genus ''Vultur'' is today used only for a completely unrelated bird of the
New World vulture The New World vulture or condor family, Cathartidae, contains seven extant species in five genera. It includes five extant vultures and two extant condors found in warm and temperate areas of the Americas. The "New World" vultures were widespr ...
family, the
Andean condor The Andean condor (''Vultur gryphus'') is a giant South American Cathartid vulture and is the only member of the genus ''Vultur''. Found in the Andes mountains and adjacent Pacific coasts of western South America, the Andean condor is the larg ...
(''Vultur gryphus'').Mindell, D. P., Fuchs, J., & Johnson, J. A. (2018). ''Phylogeny, taxonomy, and geographic diversity of diurnal raptors: Falconiformes, Accipitriformes, and Cathartiformes''. In Birds of prey (pp. 3–32). Springer, Cham. The specific scientific name for the species ''audax'', is derived from the
Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...
''audac'', meaning “bold”, indicative of the perceived disposition of these raptors, perhaps when hunting (although ironically this species is in general highly wary otherwise and even “timid” towards humans). At one time, the wedge-tailed eagle was classified in it is own monotypical genus ''Uroaetus'', perhaps due to its unique form. However, this species is clearly quite similar, in many respects of morphology, appearance, behaviour and life history, to other species in the ''Aquila'' genus.Global Raptor Information Network. 2021. Species account: ''Wedge-tailed Eagle Aquila audax''. Downloaded from http://www.globalraptors.org on 4 November 2021 The eagles of the ''Aquila'' genus are part of the subfamily
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.Lerner, H., Christidis, L., Gamau ...
, within the larger
Accipitridae The Accipitridae is one of the three families within the order Accipitriformes, and is 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-s ...
family. The subfamily is commonly referred to as booted eagles or sometimes as true eagles. These species may be distinguished from most other accipitrids by the feathering covering their legs, regardless of distribution. With some 39 or so species, the Aquilinae is distributed on every continent, excluding
Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...
. Via a variety of
phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups ...
testing, largely via
Mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...
and
Nuclear DNA Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA contained within each cell nucleus of a eukaryotic organism. It encodes for the majority of the genome in eukaryotes, with mitochondrial DNA and plastid DNA coding for the rest. I ...
genes, it has been determined that the wedge-tailed eagle clusters with certain other ''Aquila'' eagles. The species found to share the most genetic similarities is the
Verreaux's eagle Verreaux's eagle (''Aquila verreauxii'') 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 Indian black eagle (''Ictinaetus malayensis''), which lives far to ...
(''Aquila verreauxii'') of Africa. However, the Gurney's eagle (''Aquila gurneyi''), a mostly
allopatric Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...
but outwardly fairly similar eagle is clearly a very close relation of the wedge-tailed eagle and the two are likely
sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...
, most likely originating from the same radiation across the
Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
region.Lerner, H. R., & Mindell, D. P. (2005). ''Phylogeny of eagles, Old World vultures, and other Accipitridae based on Nuclear and Mitochondrial DNA''. Molecular phylogenetics and evolution, 37(2), 327–346. These species, the wedge-tailed, Gurney's and Verreaux's eagles, form a
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...
or a
species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
with the well-known
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
(''Aquila chrysaetos''), the most widely distributed species in the entire accipitrid family, as well as outwardly dissimilar (smaller and paler-bellied yet also powerful) eagles like the
Bonelli's eagle The Bonelli's eagle (''Aquila fasciata'') 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 ...
(''Aquila fasciata''), the
African hawk-eagle The African hawk-eagle (''Aquila spilogaster'') 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.Lerner, H., Christidis, L., Gamauf ...
(''Aquila spilogaster'') and the
Cassin's hawk-eagle Cassin's hawk-eagle (''Aquila africana'') or Cassin's eagle, is a relatively small eagle in the family Accipitridae. Its feathered legs mark it as member of the Aquilinae or booted eagle subfamily. A forest-dependent species, it occurs in primary ...
(''Aquila africanus''), the latter three having once been considered members of a different genus. Beyond the aforementioned species, the four other ''Aquila'' species while outwardly similar to eagles such as golden and wedge-tailed eagles, being large, dark and brownish with long wings, are thought to form a separate clade based on genetic testing and are
paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...
from the members of what can be called the golden eagle clade.Helbig, A. J., Kocum, A., Seibold, I., & Braun, M. J. (2005). ''A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level''. Molecular phylogenetics and evolution, 35(1), 147–164. Other related outliers from, currently from outside the ''Aquila'' genus, are the small-to-mid-sized '' Clanga'' or spotted eagle species and the widely found and quite small ''
Hieraeetus 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. They are medium-sized birds of prey inhabiting Europe, Asia, Af ...
'' eagles. One member of the latter genus contains the only other widely found Aquilinae eagle in Australia, the
little eagle The little eagle (''Hieraaetus morphnoides'') is a very small eagle native to Australia, measuring 45–55 cm (17–21.5 inches) in length and weighing 815 g (1.8 lb), roughly the size of a peregrine falcon. It tends to inhabit open wo ...
(''Hieraaetus morphnoides'').


Subspecies

Two subspecies of wedge-tailed eagle are recognized. However, the separation of the two subspecies has been called into question, largely because the reported differences in both
size Size in general is the magnitude or dimensions of a thing. More specifically, ''geometrical size'' (or ''spatial size'') can refer to linear dimensions ( length, width, height, diameter, perimeter), area, or volume. Size can also be me ...
and coloration can be attributed to
clinal variation Cline may refer to: Science * Cline (biology), a measurable gradient in a single trait in a species across its geographical range * Cline (hydrology), a fluid layer with a property that varies * Cline (mathematics) or generalised circle, a circ ...
and some of the insular populations may still be at an intermediate stage of subspecific formation.Austin, J. J., Olivier, L., Nankervis, D., Brown, W. E., Gardner, M. G., & Burridge, C. P. (2014). ''Twenty microsatellite loci for population and conservation genetic studies of the wedge-tailed eagle (Aquila audax)''. Australian Journal of Zoology, 62(3), 235–237. * ''A. a. audax'' (Latham, 1801) – This subspecies resides in the entire continent of Australia as well as in southern New Guinea. It is the typical wedge-tailed eagle as subsequently described. * '' A. a. fleayi'' ( Condon & Amadon, 1954) – This race is endemic to
Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...
. The subspecies is named in honour of
David Fleay David Howells Fleay (; 6 January 1907 – 7 August 1993) was an Australian scientist and biologist who pioneered the captive breeding of endangered species, and was the first person to breed the platypus (''Ornithorhynchus anatinus'') in ...
, an Australian naturalist who was the first to propose the difference of the insular race. ''A. a. fleayi'' differs from mainland wedge-tailed eagles mainly via size and colouring. It is larger than mainland eagle and is said to have particularly outsize mainland eagles in talon dimensions.Pay, J. M., Katzner, T. E., Wiersma, J. M., Brown, W. E., Hawkins, C. E., Proft, K. M., & Cameron, E. Z. (2021). ''Morphometric Sex Identification of Nestling and Free-Flying Tasmanian Wedge-Tailed Eagles (Aquila audax fleayi)''. Journal of Raptor Research. Furthermore, it is a deep chocolate brown colour rather than blackish in overall colour with a whitish buff colouring to the nape rather than tawny-rufous feathers there. The juvenile is altogether paler and sandier than equivalent aged wedge-tailed eagle on mainland Australia. Although the validity of the subspecies has been questioned, genetic studies have determined that there is no
gene flow In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent a ...
or
introgression Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Intr ...
between Tasmanian and other wedge-tailed eagles; furthermore, the insular race was likely formed by marine dispersals, a process wedge-tailed eagles may continue to engage in despite usually avoiding large bodies of water, albeit usually in narrower
strait A strait is an oceanic landform connecting two seas or two other large areas of water. The surface water generally flows at the same elevation on both sides and through the strait in either direction. Most commonly, it is a narrow ocean chan ...
s.Burridge, C. P., Brown, W. E., Wadley, J., Nankervis, D. L., Olivier, L., Gardner, M. G., Barbour, R. & Austin, J. J. (2013). ''Did postglacial sea-level changes initiate the evolutionary divergence of a Tasmanian endemic raptor from its mainland relative?'' Proceedings of the Royal Society B: Biological Sciences, 280(1773), 20132448.


Description

This is a very large and quite lanky eagle. It is characteristically black but can appear
tar Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bi ...
to
charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ...
brown depending on lighting and individual variation. Wedge-tailed eagles have a massive bill but possess a relatively small and rather flat head with a long, almost vulturine neck. Furthermore, they are distinctive for their prominent carpals and baggy feathered trousers. The species tends to perch conspicuously on dead trees, telegraph poles, rocks or the open ground at times. Between the bill size, elongated shape and prominent shoulders this species is highly distinctive, with its long wings extend well down long and markedly wedge-tipped tail while perched. They have a large proportion of bare facial skin is thought to be an adaptation to the warm climate not to carrion eating, as the non-carrion eating Verreaux's eagle has similar facial feathering and the golden eagle eats carrion too. Against the blackish plumage, the tawny-rufous hackles on the neck, forming a lanceolated shape, as well as the pale brown to rufous crissum and narrow mottled grey-brown band across the greater wing coverts all stand out well. The sexes are indistinguishable by plumage. The juvenile is mainly darkish brown with extensive rufous feather edging and a paler, fairly streaky head. Furthermore, the juvenile has a lighter brown crissum, light reddish brown to golden nape with similar colouring extending sometimes to the back and wing band. The wing band is considerably more prominent than those of adults, extending to the median and sometimes the lesser coverts. Rarely, a juvenile may be all dull black, lacking rufous edges or a wing band. The young eagles are much the same by the 2nd through the 4th years though may be almost invariably visibly in
moult In biology, moulting (British English), or molting (American English), 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 (often, but not always, an outer ...
and with a narrowing wing band. They become darker around the 5th year with a red-brown nape and a still narrowing wing band. Full mature plumage is not attained until the 7th or 8th year, although sexual maturity can be considered as early as 5. Adults have dark brown eyes, while the juvenile has similar but usually slightly darker eyes. Wedge-tailed eagles are typically creamy white on the cere and feet although these can be dull yellow, more so in juveniles than adults. The wedge-tailed eagle has a unique
moult In biology, moulting (British English), or molting (American English), 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 (often, but not always, an outer ...
process in that they moult almost continuously and very slowly, and it may take 3 or more years for an eagle of the species to complete a moult. Moults are arrested only at times of famine and happen so gradually as to not impede the flight or hunting capacities of an eagle. In flight, wedge-tailed eagles appear as a very large dark raptor with a well-protruding head, long and relatively narrow-looking wings more or less parallel edged when soaring and most distinctly a long diamond-shaped tail. The shape is fairly dissimilar from any other raptor in the world.Recher, H. F. (2020). ''The Australian Bird Guide: Revised Edition''. CSIRO Publishing. Juveniles tend to be broader winged in comparison. The wingspan is around 2.2 times greater than the total length. They tend to fly with rather loose but deep and powerful beats. Wedge-tailed eagles spend much time sailing along, looking quite stable and controlled even in strong winds. The species glides and soars on upswept wings with long splayed primaries often the ample tail may be upcurved at the edges often (or “dished”).Debus, S. (2019). ''Birds of Prey of Australia: a Field Guide''. CSIRO Publishing. The eagle often spreads its deep wing emarginations to reduce drag in high winds. Quite on the contrary to their superlative and controlled appearance once on the wing, flight for wedge-tailed eagles can be a struggle even in normal circumstances unless from it is from a pinnacle or somewhat windy and within the forest they may clamor about to reach the canopy with a "lack of grace". Gorged birds on the ground can be vulnerable due to being practically grounded, such as historically to Aboriginal hunters. Wedge-tailed eagles have been seen at more than in the air by human gliders. The adult is all blackish on the wing but for the tawny-rufous nape and greyish wing band (running less than a quarter of the way down the wing's width). Little relieves the dark coloration below but the pale brown to rufous crissum and the pale greyish bases to their
flight feather Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tai ...
s. Juvenile wedge-tailed eagles appear much browner although in general are not dissimilar in pattern below though the body and wings relative to adult. However, juveniles may show some paler mottling, of an off-rufous colour. Meanwhile, the juvenile's tail and most flight feathers are barred greyish which in turn contrast against the pale based primaries with black tips. Above, the juvenile bears much paler and more sandy rufous colour from the head to at least upper mantle and along broad wing band (as well as more than half the wing width). The lighter dorsal colour sometimes extends to much of the back and scapulars. Rare individual juvenile wedge-tailed eagles are dull black without wing band or paler edges. With much variation in individuals, generally as the young eagles age, the signature wing band shrinks incrementally and after 5th year the plumage darkens.


Size

The female wedge-tailed eagle is one of the world's largest eagles.Unwin, M., & Tipling, D. (2018). ''The Empire of the Eagle: An Illustrated Natural History''. Yale University Press. Its nearest
rival A rivalry is the state of two people or groups engaging in a lasting competitive relationship. Rivalry is the "against each other" spirit between two competing sides. The relationship itself may also be called "a rivalry", and each participant o ...
in Australia for size is some 15% smaller linearly and 25% lighter in weight. As is typical in birds of prey, the female is larger than the male; although a few individuals are larger by only 0–17%, they average up to 33% larger. A full-grown female weighs between , while the smaller males weigh . Total length varies between and the wingspan typically is between . In 1930, the average weight and wingspans of 43 birds were and . The same average figures for a survey of 126 eagles in 1932 were and , respectively. According to one guide, the mean body mass of male wedge-tailed eagles is while that of females is listed as , which, if accurate, is one of the most extreme examples of size sexual dimorphism known in any bird of prey.Cherriman, S. C. (2007). ''Territory size and diet throughout the year of the Wedge-tailed Eagle Aquila audax in the Perth region, Western Australia''. B. Sc.(Hons) Thesis, Curtin University, Western Australia. However, another sample showed far less stark size differences, with 29 males weighing an average of and 29 females an average of . In the same sample, from the
Nullarbor Plain The Nullarbor Plain ( ; Latin: feminine of , 'no', and , 'tree') is part of the area of flat, almost treeless, arid or semi-arid country of southern Australia, located on the Great Australian Bight coast with the Great Victoria Desert to its ...
, males averaged wingspan of (sample of 26) and body length of (sample 5) while females had an average wingspan of (sample 23) and body length of .Brooker, M. (1996). ''Morphometrics of the Wedge-tailed Eagle Aquila audax''. Corella, 20, 129–134. However, the Nullarbor Plain eagles appear slightly smaller than wedge-tailed eagle sizes from other surveys, based on body mass and wing chord sizes. An average length for males of and was described for wedge-tailed eagles in Queensland. Another source claimed an average male weight of and average female body mass of . Yet another book lists males as averaging and females as averaging . A sample of 10 males averaged while 19 females weighed .Parry, S. J. (2001). ''The booted eagles (Aves: Accipitridae): perspectives in evolutionary biology''. University of London, University College London (United Kingdom).Baker-Gabb, D. J. (1984). ''Morphometric data and dimorphism indices of some Australian raptors''. Corella, 8, 61–63. The mean body mass of males in Tasmania was while that for females was . The largest wingspan ever verified for an eagle was for this species. A female killed in Tasmania in 1931 had a wingspan of , and another female measured barely smaller at . Similar claims, however, have been made for the
Steller's sea eagle Steller's sea eagle (''Haliaeetus pelagicus''), also known as Pacific sea eagle or white-shouldered eagle, is a very large diurnal bird of prey in the family Accipitridae. It was described first by Peter Simon Pallas in 1811. No subspecies are ...
(''Haliaeetus pelagicus''), which has been said to reach or exceed in wingspan. Reported claims of wedge-tailed eagles spanning and were unverified and deemed to be unreliable per
Guinness World Records ''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world ...
. This eagle's great length and wingspan place it among the largest eagles in the world, but its
wings A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is expre ...
, at more than , and
tail The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammal ...
, at up to , are unusually elongated for its body weight, and nine or ten other eagle species regularly outweigh it. It is around the third heaviest ''Aquila'' species, outsized only somewhat by the
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
and slightly by the
Verreaux's eagle Verreaux's eagle (''Aquila verreauxii'') 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 Indian black eagle (''Ictinaetus malayensis''), which lives far to ...
, although it only slightly exceeds the weight of the
Spanish imperial eagle The Spanish imperial eagle (''Aquila adalberti''), also known as the Spanish eagle or Adalbert's eagle, is a species of eagle native to the Iberian Peninsula. The binomial commemorates Prince Adalbert of Bavaria. Due to its distinct “epaule ...
(''Aquila adalberti'').''CRC Handbook of Avian Body Masses, 2nd Edition'' by John B. Dunning Jr. (Editor). CRC Press (2008), . Among the entire booted eagle subfamily, in addition to the two heavier ''Aquila'', it is outsized in bulk by the martial eagle (''Polemaetus bellicosus''), while the also long-tailed
crowned eagle The crowned eagle, also known as the African crowned eagle or the crowned hawk-eagle (''Stephanoaetus coronatus''), is a large bird of prey found in sub-Saharan Africa; in Southern Africa it is restricted to eastern areas.Sinclair & Ryan (2003) ...
(''Stephanoaetus coronatus'') can average of a roughly similar body mass to the wedge-tailed eagle, although the latter is marginally the heavier bird. The wedge-tailed is significantly exceeded in body mass by only a few eagles, especially the Steller's sea eagle and harpy eagle (''Harpia harpyja'') and somewhat so by the
Philippine eagle The Philippine eagle (''Pithecophaga jefferyi''), also known as the monkey-eating eagle or great Philippine eagle, is a critically endangered species of eagle of the family Accipitridae which is endemic to forests in the Philippines. It has br ...
(''Pithecophaga jefferyi''), the
white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
(''Haliaeetus albicilla'') and the
bald eagle The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies the same niche as ...
(''Haliaeetus leucocephalus''). However, it rivals the Steller's and harpy eagles and is known to be exceeded only by the Philippine eagle in total length. The wedge-tailed eagle's wingspan is the largest of any ''Aquila'', and is exceeded amongst all eagles probably only by the white-tailed and Steller's sea eagles in average spread though its average (not maximum) wingspan is rivaled by that of the martial eagle.Mendelsohn, J.M., Kemp, A.C., Biggs, H.C., Biggs, R., & Brown, C.J. (1989). ''Wing areas, wing loadings and wing spans of 66 species of African raptors''. Ostrich, 60(1), 35-42. Among standard measurements, within the nominate subspecies, the wing chord of males may range from while that of the female is from . In Tasmania, the wing chord measured from in males and in females. In Nullarbor Plain, males averaged in wing chord while females averaged . Other Australian wedge-tailed eagles averaged in wing chord among males and among females. In Tasmania, the wing chord averaged in males and in females. The extreme tail length, slightly to greatly exceeding that of other ''Aquila'', is in males from , averaging in the Nullarbor eagles and in Tasmania, and from , averaging in Nullarbor and in Tasmania. Although they only slightly exceed in tail length the heavier two ''Aquila'' and crowned eagles and they can rival the tail lengths of the Philippine and the Harpiinae eagles, Tasmanian wedge-tailed eagles are quite likely to be the longest tailed of all modern eagles. The length of the tarsus may be from . The tarsus of 7 males averaged while that of 7 females averaged . In terms of
bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Pla ...
measurements, the exposed culmen may range from in males and in females while total bill length (from the
gape The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...
) is from and , in the sexes respectively. It is likely to be the largest billed ''Aquila'', a bit ahead of the imperial eagles and the Verreaux's eagle, behind only the larger ''
Haliaeetus A sea eagle or fish eagle (also called erne or ern, mostly in reference to the white-tailed eagle) is any of the birds of prey in the genus ''Haliaeetus'' in the bird of prey family Accipitridae. Taxonomy and evolution The genus ''Haliaeetus'' ...
'' and Philippine eagles amongst all eagles. In Tasmania, culmen lengths averaged in males and in females while the total length of the bill averaged and . The hallux claw, the enlarged rear talon on the hind toe, is slightly smaller than that of a golden or Verreaux's eagle, even proportionately, but is by no mean small and is extremely sharp. According to one study, wedge-tailed eagles had a hallux claw of , ranging from , in males , ranging from in a sample of 10, in females. Another source listed the hallux claw of mainland Australian eagles as averaging in males and in females. Meanwhile, in Tasmanian eagles, the hallux claw averaged , ranging from , in males while in females the hallux claw averaged , ranging from . In terms of
osteological Osteology () is the scientific study of bones, practised by osteologists. A subdiscipline of anatomy, anthropology, and paleontology, osteology is the detailed study of the structure of bones, skeletal elements, teeth, microbone morphology, func ...
structure and size, the wedge-tailed eagle is said to be proportional to other eagles, being notably smaller and less robust than the heaviest eagles such as Steller's and harpies but fairly similar in osteology in both structure and proportions to the golden eagle.


Identification

Their unique combination of large size, lanky build, long, diamond-shaped tail (though can be round-ended when both central feathers are moulted together), mainly black or rather dark plumage, and long wings seen when soaring or gliding make all ages of the wedge-tailed eagle fairly unmistakable in the majority of their range. The only main confusion species is often the black-breasted kite (''Hamirostra melanosternon''), which is surprisingly similar in colouring but is much smaller with a relatively short, squared tail and extensive clear white windows covering a good part of their wings. Juveniles of the
white-bellied sea eagle The white-bellied sea eagle (''Haliaeetus leucogaster''), 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 t ...
(''Haliaeetus leucogaster''), at times mentioned as potentially confusable with a young wedge-tailed eagle, are much paler below with a rather different flight pattern: a short pale tail, bare legs, shorter, broader wings held in stiff dihedral. In New Guinea, the Gurney's eagle is more similar than those species in form and build but the Gurney's is somewhat smaller and more compact than the wedge-tailed eagle with rich yellow feet, a rather shorter rounded or faintly wedge-tipped tail, shorter and relatively broader wings (in adaptation to more forest-living).Beehler, B. M., & Pratt, T. K. (2016). ''Birds of New Guinea''. Princeton University Press. Furthermore, the Gurney's eagle has a much paler immature plumage. Although usually considered an island endemic, the Gurney's eagle is possibly capable of marine dispersals, as is the wedge-tailed eagle, that may lead to them to turn up in the forests of northern Australia and historical reports show that a rare vagrant of the species may indeed appear there.
Papuan eagle The Papuan eagle (''Harpyopsis novaeguineae'') is a large bird of prey.Ferguson-Lees, J., & Christie, D. A. (2001). ''Raptors of the World''. Christopher Helm, London, UK. It is also known by several other names, including Papuan harpy eagle, New ...
(''Harpyopsis novaeguineae''), the only other island raptor in New Guinea that approaches the wedge-tailed in size is a highly distinct and forest-restricted species, being much paler, particularly below, with long bare legs and different proportions, more like a giant ''
Accipiter ''Accipiter'' is a genus of birds of prey in the family Accipitridae. With 51 recognized species it is the most diverse genus in its family. Most species are called goshawks or sparrowhawks, although almost all New World species (excepting th ...
'' with short rounded wings, a long, somewhat rounded tipped tail and a large, rounded head.


Vocalizations

The wedge-tailed eagle is not a bird well known for its vocalization nor are they often heard. They may be silent for long stretches of time, possibly months, at least outside of breeding season. When vocalizations have been documented, it usually only near the nest and in aerial display and can be hard to hear unless at close range. The commonest calls for wedge-tailed eagles are high, rather thin whistles, sometimes transcribed as ''I-see, I-see'' followed by a short descending ''see-tya''. Also documented during the breeding season are various other whistles, yelps and squeals and an often rolling series. Characteristically, all their calls are surprisingly weak though the main call is sometimes considered to have a “melancholy” quality. The opinion on their call is not dissimilar to the golden eagle, whose voice is similarly considered unimpressive. Female calls in wedge-tailed eagles are similar but are generally lower and harsher than males.


Range and habitat

Wedge-tailed eagles are found throughout Australia, including Tasmania and southern New Guinea in almost all habitats, though they tend to be more common in favourable habitat in southern and eastern Australia. In Australia, they may be found almost continuously all the way from the
Cape York Peninsula Cape York Peninsula is a large peninsula located in Far North Queensland, Australia. It is the largest unspoiled wilderness in northern Australia.Mittermeier, R.E. et al. (2002). Wilderness: Earth’s last wild places. Mexico City: Agrupación ...
in the north down to
Wilsons Promontory National Park The Wilsons Promontory National Park, commonly known as Wilsons Prom or The Prom, is a national park in the Gippsland region of Victoria, Australia, located approximately southeast of Melbourne. The national park is the southernmost national ...
and
Great Otway National Park The Great Otway National Park is a national park located in the Barwon South West region of Victoria (Australia), Victoria, Australia. The national park is situated approximately southwest of Melbourne, Australia, Melbourne, in the Otway Ran ...
s in the southern tips of the continent and from
Shark Bay Shark Bay ( Malgana: ''Gathaagudu'', "two waters") is a World Heritage Site in the Gascoyne region of Western Australia. The http://www.environment.gov.au/heritage/places/world/shark-bay area is located approximately north of Perth, on the ...
in the western side of the continent to
Great Sandy National Park Great Sandy National Park is a coastal national park in the Fraser Coast Region, Queensland, Australia. Geography The park features untouched beaches, large sand dunes, heathlands, rainforests, swamps, creeks, freshwater lakes and mangrove fore ...
and
Byron Bay Byron Bay (Minjungbal: ''Cavvanbah)'' is a beachside town located in the far-northeastern corner of the state of New South Wales, Australia on Bundjalung Country. It is located north of Sydney and south of Brisbane. Cape Byron, a headla ...
in the east. They are widespread throughout the desert interior of Australia, however are rare or occur at low densities in the most arid parts of the continent, such as the
Lake Eyre Basin The Lake Eyre basin ( ) is a drainage basin that covers just under one-sixth of all Australia. It is the largest endorheic basin in Australia and amongst the largest in the world, covering about , including much of inland Queensland, large porti ...
. Offshore, the wedge-tailed eagle may be distributed in several of the larger and some of the smaller Australian islands. These include a majority of the
Torres Strait Islands The Torres Strait Islands are a group of at least 274 small islands in the Torres Strait, a waterway separating far northern continental Australia's Cape York Peninsula and the island of New Guinea. They span an area of , but their total la ...
,
Albany Island Albany Island or Pabaju is an island off the north-eastern coast of Cape York Peninsula in the Adolphus Channel and part of the Manar Group of islands of Queensland, Australia. It is within the locality of Somerset in the Shire of Torres. ...
, Pipon Island, the isles of
Bathurst Bay Bathurst Bay is a bay in the localities of Lakefield and Starcke in the Shire of Cook, Queensland, Australia. In the 19th century it was the base for the pearling fleet. It is now a tourist attraction on Cape York Peninsula in northern Qu ...
, many small isles in Queensland from Night Island down to the South Cumberland Islands,
Fraser Island Fraser Island ( Butchulla: ) is a World Heritage-listed island along the south-eastern coast in the Wide Bay–Burnett region, Queensland, Australia. The island is approximately north of the state capital, Brisbane, and is within the Fras ...
,
Moreton Island Moreton Island (Mulgumpin) is an island on the eastern side of Moreton Bay on the coast of South East Queensland, Australia. The Coral Sea lies on the east coast of the island. Moreton Island lies northeast of the Queensland capital, Brisban ...
,
North Stradbroke Island North Stradbroke Island ( Jandai: ''Minjerribah''), colloquially ''Straddie'' or ''North Straddie'', is an island that lies within Moreton Bay in the Australian state of Queensland, southeast of the centre of Brisbane. Originally there was onl ...
, Montague Island,
Kangaroo Island Kangaroo Island, also known as Karta Pintingga (literally 'Island of the Dead' in the language of the Kaurna people), is Australia's third-largest island, after Tasmania and Melville Island. It lies in the state of South Australia, southwest ...
, the
Nuyts Archipelago The Nuyts Archipelago is an island group located in South Australia in the Great Australian Bight to the south of the town of Ceduna on the west coast of the Eyre Peninsula. It consisting of mostly granitic islands and reefs that prov ...
,
Groote Eylandt Groote Eylandt ( Anindilyakwa: ''Ayangkidarrba'' meaning "island" ) is the largest island in the Gulf of Carpentaria and the fourth largest island in Australia. It was named by the explorer Abel Tasman in 1644 and is Dutch for "Large Island" i ...
and the
Tiwi Islands The Tiwi Islands ( tiw, Ratuati Irara meaning "two islands") are part of the Northern Territory, Australia, to the north of Darwin adjoining the Timor Sea. They comprise Melville Island, Bathurst Island, and nine smaller uninhabited islands, w ...
. In Tasmania, they may be found essentially throughout as well as some isles of the
Kent Group The Kent Group are a grouping of six granite islands located in Bass Strait, north-west of the Furneaux Group in Tasmania, Australia. Collectively, the group is comprised within the Kent Group National Park. The islands were named Kent's ...
,
Bass Strait Bass Strait () is a strait separating the island states and territories of Australia, state of Tasmania from the Australian mainland (more specifically the coast of Victoria (Australia), Victoria, with the exception of the land border across Bo ...
,
Flinders Island Flinders Island, the largest island in the Furneaux Group, is a island in the Bass Strait, northeast of the island of Tasmania. Flinders Island was the place where the last remnants of aboriginal Tasmanian population were exiled by the colo ...
and
Cape Barren Island Cape Barren Island, officially truwana / Cape Barren Island, is a island in the Bass Strait, off the north east coast of Tasmania, Australia. It is the second largest island of the Furneaux Group; Flinders Island lies to the north, with th ...
.Fielding, M. W., Buettel, J. C., & Brook, B. W. (2020). ''Trophic rewilding of native extirpated predators on Bass Strait Islands could benefit woodland birds''. Emu-Austral Ornithology, 120(3), 260–262. In New Guinea, the wedge-tailed eagle is highly range restricted and can be found in predominantly in the Trans-Fly savanna and grasslands and the general area around the
Western Province Western Province or West Province may refer to: * Western Province, Cameroon *Western Province, Rwanda *Western Province (Kenya) *Western Province (Papua New Guinea) *Western Province (Solomon Islands) *Western Province, Sri Lanka *Western Provin ...
, as well as in the
Merauke Regency Merauke Regency is a regency in the far south of the Indonesian province of South Papua. It covers an area of 46,791.63 km2, and had a population of 195,716 at the 2010 Census and 230,932 at the 2020 Census; the official estimate as at mid 2 ...
, with some isolated reports in
Western New Guinea Western New Guinea, also known as Papua, Indonesian New Guinea, or Indonesian Papua, is the western half of the Melanesian island of New Guinea which is administered by Indonesia. Since the island is alternatively named as Papua, the region ...
, the
Bensbach River The Bensbach River is a river in southwestern Papua New Guinea. It is located just to the east of the Maro River in Merauke Regency, Indonesia, and just to the west of the Morehead River in Papua New Guinea. The mouth of the river, Torasi Estuar ...
and the Oriomo River.


Habitat

The wedge-tailed eagle inhabits an extremely wide range of habitats. Although range restricted relative to the golden eagle, it likely occupies a wider range of habitat types than likely any other ''Aquila'' eagle and indeed may outrival any booted eagle species in their usage of diverse habitats, being somewhat more akin to habitat generalist raptors such as ''
Buteo ''Buteo'' is a genus of medium to fairly large, wide-ranging raptors with a robust body and broad wings. In the Old World, members of this genus are called "buzzards", but " hawk" is used in the New World (Etymology: ''Buteo'' is the Latin na ...
'' buzzards. Assorted habitats known to host wedge-tailed eagles includes open
woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...
,
savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground ...
,
heath A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler a ...
land,
grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...
s, desert edge and
semi-desert A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi ...
,
subalpine forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
s, montane grasslands and
mountain peaks A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. The topographic terms acme, apex, peak (mountain peak), and zenith are synonymous. The term (mountain top) is generally used only for a m ...
, not-too-dense
tropical rainforest Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equator ...
s, monsoon forests, dwarf conifer forests, some
wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...
s as well as regularly forays to
coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...
al areas, though normally along the coasts they occur around
plains In geography, a plain is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and as plateaus or uplands. In ...
somewhat away from the water. Favored habitat tends to be remote or rough country, at least partially wooded and not uncommonly varied with some rocky spots as well as in
shrubland Shrubland, scrubland, scrub, brush, or bush 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. It ...
. Wedge-tailed eagles seem to prefer some
dead trees ''Dead Trees'' is the fifth studio album by post-hardcore band From First to Last, released April 23, 2015, via Sumerian Records. It is the first and only release to feature vocalist Spencer Sotelo (singer of progressive metal band Periphery), Ta ...
to be present. They may occur around ''
Eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as ...
'' woodland quite regularly, as well as ''
Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus nam ...
'' woodland and mixed woodlands of ''
Casuarina cristata ''Casuarina cristata'' is an Australian tree of the sheoak family Casuarinaceae known as belah. It is native to a band across inland eastern Australia. Taxonomy The Dutch botanist Friedrich Anton Wilhelm Miquel described the belah in 1848, and ...
-
Flindersia maculosa ''Flindersia maculosa'', commonly known as leopardwood or leopard tree, is a species of tree in the family Rutaceae and is endemic to inland areas of eastern Australia. It has mottled bark, simple leaves arranged in opposite pairs, white to cre ...
-
Callitris ''Callitris'' is a genus of coniferous trees in the Cupressaceae (cypress family). There are 16 recognized species in the genus, of which 13 are native to Australia and the other three (''C. neocaledonica, C. sulcata'' and ''C. p ...
''
cypresses Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the la ...
and also stands of ''
Casuarina cunninghamiana ''Casuarina cunninghamiana'', commonly known as river oak or river she-oak, is a she-oak species of the genus ''Casuarina''. The native range in Australia extends from Daly River in the Northern Territory, north and east in Queensland and easte ...
''.Sharp, A., Norton, M., & Marks, A. (2001). ''Breeding activity, nest site selection and nest spacing of wedge-tailed eagles, Aquila audax, in western New South Wales''. Emu, 101(4), 323–328.Collins, L.., & Croft, D. B. (2007). ''Factors influencing chick survival in the Wedge-tailed Eagle Aquila audax''. Corella, 31, 32–40.Silva, L. M., & Croft, D. B. (2007). ''Nest-site selection, diet and parental care of the wedge-tailed eagle Aquila audax in western New South Wales''. Corella, 31(2), 23–31. A strong preference was detected for ''C. cunninghamiana'' alternatively with several ''Eucalyptus'' species was detected in the
Australian Capital Territory The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding township#Aust ...
, sloping ground allowing good access and access to tall, mature trees being paramount to the eagles in the study.Hatton, F., Mickan, P. H., Gruber, B., & Olsen, J. (2014). ''Modelling the nesting habitat requirements of the wedge-tailed eagle Aquila audax in the Australian Capital Territory using nest site characteristics''. Corella, 38, 63–70. Quite often they will be seen soaring over
hill A hill is a landform that extends above the surrounding terrain. It often has a distinct summit. Terminology The distinction between a hill and a mountain is unclear and largely subjective, but a hill is universally considered to be not a ...
s,
mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher ...
s or
escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...
s as well as over flat plains, especially spinex grassland. Dense forest is typically avoided with glades and
edge Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed ...
often sought out in forested areas. While they do occur in rich riparian woodlands, it is with relative scarcity despite this being where many other raptors of the nation concentrate.Aumann, T. (2001). ''An intraspecific and interspecific comparison of raptor diets in the south-west of the Northern Territory, Australia''. Wildlife Research, 28(4), 379–393. In the deserts of the
Lake Eyre basin The Lake Eyre basin ( ) is a drainage basin that covers just under one-sixth of all Australia. It is the largest endorheic basin in Australia and amongst the largest in the world, covering about , including much of inland Queensland, large porti ...
, they are often seen in gibber plains along treed
watercourse A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams a ...
s and
drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...
s, here often concentrated around ''Eucalyptus'' in stony creek beds. In the
sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...
y desert areas of
Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to t ...
, wedge-tailed eagles were once reasonably common but have largely vacated the region after the macropod prey they live off of there were all but hunted to extinction.Johnstone, R. E., & Storr, G. M. (1998). ''Handbook of Western Australian Birds (Vol. 2)''. Western Australian Museum. Wedge-tailed eagles commonly occur from sea level up to about with seemingly no preference based on altitudinal level. A fairly pronounced liking for mountainous localities such as
plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ...
s has been detected in a few studies of wedge-tailed eagle. One of the few habitat types considered to be strongly avoided by wedge-tailed eagles are areas intensively
settled A settler is a person who has migrated to an area and established a permanent residence there, often to colonize the area. A settler who migrates to an area previously uninhabited or sparsely inhabited may be described as a pioneer. Settle ...
or cultivated areas. A slightly fading tendency to avoid human areas has been detected, perhaps as persecution rates have gone far down, and the wedge-tailed eagle may be seen near
town A town is a human settlement. Towns are generally larger than villages and smaller than cities, though the criteria to distinguish between them vary considerably in different parts of the world. Origin and use The word "town" shares an o ...
s and villages in exurban and even suburban areas largely within bushland. However, the species is seldom seen other than as a flyover in more developed towns and cities. Additionally, it is not uncommon in manmade spots such as pasture areas, High-grading, forestry clearings, and rolling Arable land, farmland areas.


Behaviour

This impressive bird of prey spends much of the day perching in trees, on rocks as well as similar exposed lookout sites such as cliffs from which it has a good view of its surroundings. Alternatively, they may sit on the ground for long periods of time or watch from a lower point, such as or Mound-building termites, termite mounds or Ant colony, anthills. Now and then, it takes off from its perch to fly low over its territory. Especially whilst not breeding, wedge-tailed eagles spends a considerable amount of the day on the wing. Wedge-tailed eagles are highly aerial, soaring for hours on end without wingbeat and seemingly without effort, regularly reaching and sometimes considerably higher. The purpose of soaring has received little specific study in wedge-tailed eagles, but it is likely, as in other accipitrids, in large part for surveying the territory and advertising their presence to other eagles. During the intense heat of the middle part of the day, it often soars high in the air, circling up on the thermal currents that rise from the ground below. Often when on the wing, it is scarcely visible to the human's naked eye. Their keen eyesight extends into ultraviolet bands. With a visual perception some three times more acute than those of humans, one of the largest pecten oculi of any bird and an eye roughly as big as a small human's, they may be one of the most sharp-eyed birds in the world. The wedge-tailed eagle is a largely sedentary as expected of a raptor dwelling in the subtropics, although they also dwell in the tropics (far northern Australia and New Guinea) as well as in the Temperate climate, temperate zone (Tasmania). However, juveniles of the species can be quite dispersive. In some cases, they have moved to a recorded distance of some . These extreme movements have been completed within 7 to 8 months after dispersal. More typically they move no farther than or so. The adult eagles can also be nomadic, though only in circumstances such as drought conditions. In turn this explains the species presence in places they don't breed, even adults. In addition to moving for drought in arid zone, also moves in highest part of New South Wales, e.g. the Snowy Mountains, the species often apparently vacates snow-covered alpine zone in winter. The small New Guinea population is apparently indistinguishable from the mainland race and so possibly result of recent colonization, although no records exist of migrating wedge-tailed eagles islands past the Torres Straits. However, it can be projected from its presence in various offshore islands its capacity for crossing straits ranging up to as far as apart. One post dispersal young eagle was observed to distribute from
Kangaroo Island Kangaroo Island, also known as Karta Pintingga (literally 'Island of the Dead' in the language of the Kaurna people), is Australia's third-largest island, after Tasmania and Melville Island. It lies in the state of South Australia, southwest ...
to the mainland, possibly a regular occurrence.Debus, S. J. (2015). ''Assessment of band recoveries for three Australian eagle species''. Corella. Due to their tendency for wandering, some authors class the wedge-tailed eagles as a “Bird migration, partial or irruptive migrant”. However, while they are arguably irruptive, it does not fit the mold of a true migrant well since under normal circumstances adults are rather sedentary unless environmental changes force them to move. The wedge-tailed eagle is the only bird that has a reputation for not infrequently attacking Hang gliding, hang gliders and Paragliding, paragliders, although other eagles including the golden eagle have also been recorded to behave thusly. Based on the response the eagles show to the gliders, they presumably are defending their territory and treating the perceived intruder like another eagle. Cases are recorded of the birds damaging the fabric of these gliders with their talons as well as some other parts of the gliding apparatus, but not the humans themselves, has been reported.Meredith, P. (1990). ''Encounters between Wedge-tailed Eagles and Hang-gliders''. Australian Bird Watcher, 13(5), 153–155. They have also been reported to attack and destroy unmanned aerial vehicles used for mining survey operations in Australia. The presence of a wedge-tailed eagle often causes panic among smaller birds, and as a result, aggressive species such as Australian magpie, magpies (one of the most vulnerable types of passerine to eagle attacks), butcherbirds, Willie wagtail, wagtails, Restless flycatcher, monarch flycatchers, Masked lapwing, lapwings, and Noisy miner, miners as well as smaller birds of prey, including both accipitrids and falcons, any of which may aggressively Mobbing (animal behavior), mob eagles (see video). Multiple species may join the kerfuffle and mob them, especially while the eagles perched, often engaging in noisy calling, presumably meant to disorient the predator, and occasionally in physical attacks against the eagle, typically focused where the big, relatively lumbering eagles could not grasp the attacking birds. The wedge-tailed eagle usually does not engage its tormentors but sometimes rolls in the air to present talons whether perched or not. Sometimes wedge-tailed eagles appear to fight but this and other behaviours, especially between young eagles, may be interpreted as playful. Some such behaviours have included fetching sticks tossed by others, athletic flipping between juvenile eagles and even playing games with dogs, via floating above them until the dogs bark or leap then floating up until the dog settles and then repeating the “game”. Flocking behaviour has been noted, similar to that of vultures (Cathartidae and
Accipitridae The Accipitridae is one of the three families within the order Accipitriformes, and is 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-s ...
) in other countries, when
carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
is available.Bird watcher's Tasmanian wedge-tailed eagle photo shows group's vulture-like behaviour
Georgie Burgess, ABC News Online, 27 April 2022
File:Wedge-tailed Eagle dayboro.ogv, In flight, 'mobbed' by Australian magpie, Dayboro, Queensland, Dayboro, SE Queensland File:Wedge-tailed Eagle sam95.ogg, Samsonvale, SE Queensland, Australia


Dietary biology

The wedge-tailed eagle is one of the world's most powerful avian predators. Due to its formidable and dominating nature, it is sometimes nicknamed “King of Birds”, along with golden eagles. Prey is usually grabbed via a pounce or snatch during a gliding flight or a tail-chase from low quartering or transect flights.Cowell, G. (2006). ''Wedge-tailed Eagle takes juvenile Kangaroo''. Boobook 24, 46. Prey is not infrequently spotted from a soaring flight and they may undertake a long, slanting stoop towards it. They may be able to spot prey from farther than a kilometer given their keen vision. Its typical hunting style is not all-together dissimilar from that of golden or Verreaux's eagles. Occasionally, a wedge-tailed eagle still hunts from a perch. Unsuccessful hunts typically exceed in number successful ones. Hunting habitat can be highly variably and can manage to capture prey in both open country and quite thick woodland or forest, though typically require an open understory in the latter. Almost all its prey is taken on the ground but to a lesser extent it may be taken from the tree Canopy (biolog), canopy. They've been known to take birds such as currawongs and cockatoos by coming around them by surprise around a tree or by darting out in flight at close range for a brief tail-chase.Whelan, D. (2009) Eagle takes cockatoo. Boobook 27, 16. Sometimes, an eagle may pull brushtail possums and other mammals from Tree hollow, tree cavities, as well as young birds from a nest.Olsen, J., Fuentes, E., Rose, A. B., & Trost, S. (2006). ''Food and hunting of eight breeding raptors near Canberra, 1990–1994''. Australian Field Ornithology, 23(2), 77–95. They've been known to follow wildfires to search for fleeing animals or alternately tractors and other farm equipment for the same purpose. Wedge-tailed eagles occasionally Kleptoparasitism, pirate food from other predators. An eagle of the species can carry prey of at least . Large animals may be attacked by pairs or, occasionally by groups, acting Pack hunter, cooperatively. One record shows 15 wedge-tailed eagles hunting Red kangaroo, kangaroos, two at a time actively chasing then repeatedly being replaced by two more from the circling group overhead.McGregor, B. (2007). ''Wedge-tailed Eagle hunting behaviour''. Boobook 25, 14.Aumann, T. (2001). ''Habitat use, temporal activity patterns and foraging behaviour of raptors in the south-west of the Northern Territory, Australia''. Wildlife Research, 28(4), 365–378. Regardless of prey size and season, tandem hunts, mainly by breeding adult pairs or sometimes loosely associated young eagles, are not uncommon. Of 89 observed hunts in Central Australia around one-third were cooperative ones. As in other tandem hunting raptors, one eagle typically lies in wait generally unseen while the other eagle distracts and drives the prey towards it. When hunting domesticated prey, they've been seen to land near livestock mothers to intimidate them and separate their young, so they can attack the latter. Sometimes, wedge-tailed eagles may use fences to limit a prey's escape routes. In some cases, these eagles will attempt to force large prey such as kangaroos and dingos to fall off steep hillsides and injure themselves. At times, wedge-tailed eagles appear to hunt at earliest light or late twilight in order to come upon Nocturnality, nocturnal prey such as hare-wallaby and bettongs. These eagles have been seen removing rabbits from traps and eating carrion in bright moonlight as well. At times, remarkably, wedge-tailed eagles have been covering large prey with vegetation, apparently to Hoarding (animal behavior), cache food too heavy to carry. Carrion is a major diet item, also; wedge-tails can spot the activity of Australian raven, ravens around a carcass from a great distance, and glide down to appropriate it. Carrion consumption is recorded in all season and contexts, although generally non-breeding birds are more likely to Scavenger, scavenge and young wedge-tailed eagles, even more so shortly post-dispersal, are thought to be far more likely to scavenge on carrion than adults generally. Wedge-tailed eagles are often seen by the roadside in rural Australia, feeding on animals that have been Roadkill, killed in collisions with vehicles. The importance of carrion relative to live prey has not been greatly studied but away from human development, especially roads, carrion is less likely to be encountered and eagles of all ages must presumably hunt to survive. In general, Australian Accipitridae, accipitrids of many species not infrequently come to carrion and they along with large passerines like ''Corvus'' species and currawongs probably fulfill the Ecological niche, niche that Old World vulture, vultures do in other continents to some extent, albeit with considerably less specialization. Aggregations of wedge-tailed eagles may occur not infrequently at large carcasses, with up to 5–12 eagles or sometimes 20 gathering. A wedge-tailed eagle can gorge up to at a sitting and, when fulfilled, can lasts for an unusual amount of time, for up to weeks or even a month, before needing to hunt again, apparently due to the warmth of the environment. After feeding they may disgorge a relatively small Pellet (ornithology), pellet, long by wide and weighing some . Usually the diet is determined from a combination of reviewing these pellets along with loose prey remains.


Prey spectrum

Pogona vitticeps (32494027291).jpg, Regular wedge-tailed eagle prey can vary in size down to small lizards such as Pogona, bearded dragons, their favourite variety of reptilian prey. CSIRO ScienceImage 1147 European rabbit.jpg, The Rabbits in Australia, introduction of rabbits to Australia has been greatly harmful to the Australian environs but a boon to opportunistic wedge-tailed eagles, which often take them in great numbers. Large Eastern Grey male kangaroo (9645655070).jpg, Regular prey can range up to the size of large adult kangaroos such as eastern grey kangaroos, usually attacked in Pack hunter, hunting pairs. Galahs.jpg, A diversity of birds may be taken with medium-sized, common birds such as galahs taken relatively frequently due to the conspicuousness. The wedge-tailed eagle is a dietary generalist, opportunistically capturing a wide range of prey species. Its prey spectrum is quite broad, with well over 200 prey species documented to be taken and even this includes very few prey only from secondary accounts from Tasmania and New Guinea.Olsen, J., Judge, D., Fuentes, E., Rose, A. B., & Debus, S. J. (2010). ''Diets of wedge-tailed eagles (Aquila audax) and little eagles (Hieraaetus morphnoides) breeding near Canberra, Australia''. Journal of Raptor Research, 44(1), 50–61. The wedge-tailed eagles tends to prefer smallish to fairly large
mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...
s as prey. However, they not infrequently take ample numbers of both
bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s and
reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...
s, along with scarcely other prey taxon. Out of 21 accrued dietary studies, 61.3% of prey items by number in the foods during nesting efforts were mammals, 21.6% were birds, 13.2% were reptiles, 2.1% by invertebrates, principally insects, 1.5% by fish, and almost no amphibians by number. Meanwhile, out of the 21, 13 studies calculated estimated biomass, and found that just shy of 90% of prey biomass was made of by mammals, 6.2% by birds and 3.4% by reptiles. Out of the ''Aquila'' genus, it is one of a few generalist species, however the wedge-tailed eagle is the ''Aquila'' most likely to typically attack the largest prey. Generally, this species prefers to attack birds and reptiles weighing over and mammals weighing over , although prey taken at times has varied from a few grams to more than sixteen times the weight of an individual eagle. A comparison estimate posited that around 2% of wedge-tailed eagle prey weighs less than , 4% of their prey weighs , 7% of their prey weighs , 10% weighs , 20% weighs , 25% weighs , 18% weighs and 14% weighs over . Projected from this comparison, the mean prey size for wedge-tailed eagles is estimated at , similar but just slightly ahead of the Verreaux's eagle and some 14% ahead of the golden eagle global mean prey size. Further studies estimated mean prey weight, showing the mean prey weigh in the Canberra-
Australian Capital Territory The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding township#Aust ...
region in three different studies was estimated to be , and , changing likely due to the shifting significances of Leporidae, leporids and larger macropods.Olsen, J., Fuentes, E., & Rose, A. B. (2006). ''Trophic relationships between neighbouring White-bellied Sea-Eagles (Haliaeetus leucogaster) and Wedge-tailed Eagles (Aquila audax) breeding on rivers and dams near Canberra''. Emu-Austral Ornithology, 106(3), 193–201.Debus, S. J. S., Olsen, J., Trost, S., & Fuentes, E. (2021). ''Breeding diets of the little eagle Hieraaetus morphnoides and wedge-tailed eagle Aquila audax in the Australian capital territory in 2011–2019''. Australian Field Ornithology, 38, 19–28. In a small study from Armidale, New South Wales, it was estimated that mean prey weight was .Debus, S. J., Hatfield, T. S., Ley, A. J., & Rose, A. B. (2007). ''Breeding biology and diet of the Wedge-tailed Eagle Aquila audax in the New England region of New South Wales''. Australian Field Ornithology, 24(3), 93–120. It only ranks behind the crowned eagle and harpy eagle and rivals the martial eagle as the eagle likely to attack the largest prey on average.


Mammals

While the introduction of
invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adv ...
to Australia has been generally having a negative to devastating effect on native animals and ecosystems, the wedge-tailed eagle is one of a few native species to largely benefit from these introductions. This is especially due to the introduction of the
European rabbit The European rabbit (''Oryctolagus cuniculus'') or coney is a species of rabbit native to the Iberian Peninsula (including Spain, Portugal, and southwestern France), western France, and the northern Atlas Mountains in northwest Africa. It has b ...
, which were deliberately introduced repeatedly (abortively in 1859 and then via a concerted effect from 1937 to 1950), largely so the wealthy could hunt them.Fenner, F. (2010). ''Deliberate introduction of the European rabbit, Oryctolagus cuniculus, into Australia''. Revue Scientifique et Technique, 29(1), 103. The wedge-tailed eagles quickly took to the rabbits as prey along with another introduced leporid, the European hare (''Lepus europaeus''). In almost every part of Australia, these eagles take Rabbits in Australia, rabbits in some numbers and they usually constitute the bulk of the prey species in most, if not all, Australian food studies. In some dietary studies rabbits have accounted for up to 89.2% of the diet by number and 86% by biomass, as in Bacchus Marsh, however they more typically range from 16% to 49% of the diet by number in various studies.Foster, A., & Wallis, R. (2010). ''Breeding diet of the wedge-tailed eagle Aquila audax in southern Victoria''. Corella, 34, 45–48.Hull, C. (1986). ''The diet of the Wedge-tailed Eagle, Aquila audax, breeding near Melbourne''. Corella, 10, 21 (4). One Canberra study found that 98.5% of the rabbits taken were adults. In the largest study near Canberra, over 5.5 years, 19.3% of the diet of wedge-tailed eagles was rabbits (12.7% of prey biomass) among 1421 prey items, so the eagles took a total of some 275 rabbits in the 11 to 17 studied territories of the area. A study estimated that mean weight of wild rabbits in Australia was , lower than estimated in the past.Sharp, A., Gibson, L., Norton, M., Ryan, B., Marks, A., & Semeraro, L. (2002). ''The breeding season diet of wedge-tailed eagles (Aquila audax) in western New South Wales and the influence of rabbit calicivirus disease''. Wildlife Research, 29(2), 175–184. However, other studies estimated the mean weights of rabbits taken by wedge-tailed eagles as variously from or “usually over ”, infrequently reported to , size of the rabbits being perhaps limited the poorly-suited soil and environs of the Australian wildlands.Parker, B. D., Hume, I. D., & Boles, W. E. (2007). ''Diet of breeding Wedge-tailed Eagles Aquila audax in south-central Queensland''. Corella, 31, 50–62. Meanwhile, the European hare is neither as widely established nor as prolifically taken as rabbits by wedge-tailed eagles but are by no means neglected and a substantial meal. With a mean body mass of , hares have been as much as nearly 10% of the local diet and up to 14% of prey biomass in studies. Rabbit haemorrhagic disease was deliberately introduced to control the population of rabbits subsequent to 1995, followed more effectively by introduction of myxoma virus to limit the damage rabbits have inflicted on native vegetation and resultingly have competed native mammals like wallabies out of parts of their range. Ultimately, the rabbit population may have more than halved and locally have been some 90% reduced. As a matter of consensus, the wedge-tailed eagles do not appear to be adversely affected in major ways by the biological control of rabbits since they can revert to primarily taking native prey species quite readily.Olsen, J., Cooke, B., Trost, S., & Judge, D. (2014). ''Is wedge-tailed eagle, Aquila audax, survival and breeding success closely linked to the abundance of European rabbits, Oryctolagus cuniculus?'' Wildlife Research, 41(2), 95–105. In the region of Broken Hill, White Cliffs, New South Wales, White Cliffs and Cunnamulla, rabbits have gone down from accounting for 56–69% of the diet to 16–31% of it. Furthermore, wedge-tailed eagles have been known to successfully maintain population in the absence of any rabbits in a few areas.Fitzsimons, J. A., Carlyon, K., Thomas, J. L., & Rose, A. B. (2014). ''The breeding diet of Wedge-tailed Eagles Aquila audax in the absence of rabbits: Kangaroo Island, South Australia''. Corella 38, 18, 21. Much more controversial at one time than hunting introduced rabbits and hares is the wedge-tailed eagle's occasional tendency to feed on and sometimes kill domesticated livestock animals.Batey, I. (1907). ''Wedge-Tailed Eagle and Lambs''. Emu-Austral Ornithology, 7(1), 43–45.Winkel, P. (2007). F''eeding ecology of the Wedge-tailed Eagle Aquila audax in north-west Queensland: Interactions with lambs''. Corella, 31, 41–49. The predation of wedge-tailed eagles on young farm animals has been the primary historic driver for the persecution of the species.Thirgood, S., Woodroffe, R., & Rabinowitz, A. (2005). ''The impact of human-wildlife conflict on human lives and livelihoods''. Conservation Biology Series-Cambridge-, 9, 13. However, in no known study have domestic livestock been known to be primary prey. The closest association with them was in northwestern Queensland where Sheep, lambs (''Ovis aries'') made up 32.7% of prey in pellets and 17.1% in remains, accounting for 15–21% of the prey biomass, while juvenile pigs (''Sus scrofa domesticus'') made up 7.3% of pellet remains and 22% of the biomass. Although it can be highly difficult, attempts have been made at parsing out whether the eagles had indeed killed the lambs rather than just lifting or dismantling them after finding them dead, as this eagle quite readily comes to carrion. The findings were that of 29 diagnosable lamb deaths in northwest Queensland, only 34.5% were due to eagle attacks. The wedge-tailed eagle is at times capable of taking very substantial livestock animals, lambs taken have been estimated to weigh a mean of or up to while fully grown sheep weighing some are infrequently vulnerable, presumably in large part to hunting pairs of eagles. In the largest study of the Canberra area, 82.5% of diagnosable sheep specimens were adults but probably were by and large scavenged. Meanwhile, young pigs included in the diet were estimated to weigh around , and sometimes feral piglets are included in the diet. When attacking lambs, the wedge-tailed eagles are apparently capable of driving their talons into the skull of the victim, although more typically they land along the back and grip the lamb along the spine until it weakens and collapses while flapping the wings for balance. This species will also land between a ewe or female pig and their respective lambs or piglets in order to separate the latter for attack. Wedge-tailed eagles are also known to at times prey on another animal introduced for human hunting purposes, the red fox (''Vulpes vulpes''), which can form up to about 4% of an eagle's breeding diet and 5% of the biomass, weighing up to . In Canberra, about 59% of the foxes found in the diet were adults. Additionally, feral cats, mainly juveniles, can be part of their prey. The primary native prey of wedge-tailed eagles is presumably marsupials, particularly Macropodiformes, macropods, which also lines up with studies where rabbits have declined or never occurred.Richards, J. D., & Short, J. (1998). ''Wedge-tailed eagle Aquila audax predation on endangered mammals and rabbits at Shark Bay, Western Australia''. Emu, 98(1), 23–31. Many wallabies, kangaroos and associated animals are included in the diet, with over 50 marsupials known in the species’ prey spectrum. When selecting marsupials, wedge-tailed eagles tend to ignore smaller species and focus on larger sized ones. However, they generally most often take alive the young, small and sickly of large macropod marsupials. Findings were that juvenile macropods were taken out of proportion to their numbers in the environment, unlike rabbits which were taken roughly in proportion to their abundance. Also they in recent times have regularly been known to come marsupials such as kangaroos that are
roadkill Roadkill is an animal or animals that have been struck and killed by drivers of motor vehicles on highways. Wildlife-vehicle collisions (WVC) have increasingly been the topic of academic research to understand the causes, and how it can be ...
s (and are known to come introduced rabbits and foxes and livestock animals killed by cars as well). There is little evidence that macropods delivered to nests are usually roadkills or from carrion, the source of prey is difficult to determine because examinations are usually done after breeding is complete to minimize disturbance. Also attendance at carrion by wedge-tailed eagles is disproportionately done by juvenile eagles. In one study of roadkills in Australia, the species ranked around 4th by frequency and capacity for carcass breakdown of scavengers at roadkills, behind feral pigs, red foxes and ravens. A video surveillance study at the nest determined that seemingly freshly killed, albeit usually quite young macropods were delivered to nests near Broken Hill. As much as 20% to 30% of the diet can be made up of by macropods. Large and prominent species are known including the Macropus, grey kangaroos and the red kangaroo (''Osphranter rufus''). Generally, juveniles are targeted of these large species with eastern grey kangaroos (''Macropus giganteus'') estimated to weigh when taken by wedge-tailed eagles, in Australian Capital Territory and New South Wales, while the weight of young western grey kangaroos (''Macropus fuliginosus'') was said to be in one study in Western Australia. The estimated weight of juvenile red kangaroos taken was in northwestern Queensland where they were the primary prey species ahead of lambs. However, wedge-tailed eagles do not shy away from attacking large, adult macropods. They've been recorded attacking eastern grey kangaroos weighing over . In one case, a huge male eastern grey kangaroo, estimated to stand was successfully dispatched by a pair of wedge-tailed eagles.Fuentes, E., & Olsen, J. (2015). ''Observations of the killing of large macropods by Wedge-tailed Eagles Aquila audax''. Australian Field Ornithology, 32(3), 160–166. Furthermore, an adult female western grey kangaroo was witnessed to be killed “in a few minutes” by a hunting pair of wedge-tailed eagles and the eagles are considered a serious predator of the western grey. Similarly large adult macropods killed by these eagles can include common wallaroos (''Osphranter robustus'') (mean adult weight around ), antilopine kangaroo (''Osphranter antilopinus'') (mean adult weight around ), agile wallaby (''Notamacropus agilis'') (median adult weight around ), black-striped wallaby (''Notamacropus dorsalis'') (median adult weight around ), red-necked wallaby (''Notamacropus rufogriseus'') estimated to weigh around when taken, swamp wallaby (''Wallabia bicolor'') (mean adult weight around ), and even red kangaroo adults. In some unusual cases, wedge-tailed eagle hunting parties can form whilst hunting red kangaroos, sometimes including up to 15 eagles (more loose, opportunistic Aggregation (ethology), aggregations than well-organized Pack hunter, groups), but usually only a pair is sufficient to kill such prey. Normally, the eagles repeatedly attack the kangaroo, sinking their talons into the back or nape and then fly up, when the second eagle starts doing the same. In some cases as many as 123 attacks have been carried out against large kangaroo before they succumb. When attacking joeys, eagles in some cases may have intentionally gotten a mother kangaroo to dislodge its joey from its pouch in order to capture and fly off with the joey. In extreme cases, wedge-tailed eagles have killed kangaroos weighing approximately . In addition, several smaller and more elusive macropods are taken including tree-kangaroos, Lagorchestes, hare-wallabies, Bridled nail-tail wallaby, nail-tail wallabies, rock-wallaby, rock-wallabies, Macleay's dorcopsis, dorcopsises and pademelons.Cherriman, S. C. (2013). ''Nest Sites, Breeding, Satellite Telemetry and Diet of the Wedge-tailed Eagle Aquila audax at Lorna Glen, Western Australia''. Other marsupials are by no means neglected. In
Shark Bay Shark Bay ( Malgana: ''Gathaagudu'', "two waters") is a World Heritage Site in the Gascoyne region of Western Australia. The http://www.environment.gov.au/heritage/places/world/shark-bay area is located approximately north of Perth, on the ...
, hare-wallabies and bettongs seem to form the central part of the diet. Another dietary favorite is the common brushtail possum (''Trichosurus vulpecula''), weighing some , which was important supplemental prey in the Perth area and was the primary prey species on
Kangaroo Island Kangaroo Island, also known as Karta Pintingga (literally 'Island of the Dead' in the language of the Kaurna people), is Australia's third-largest island, after Tasmania and Melville Island. It lies in the state of South Australia, southwest ...
, at 33% of the diet there. Around Perth, other small, nocturnal marsupials were taken in some numbers including woylies (''Bettongia penicillata'') and southern brown bandicoots (''Isoodon obesulus''). The common ringtail possum (''Pseudocheirus peregrinus'') was the second most prominent prey species in the diet near Melbourne, composing 20.1% of the diet, with some numbers of common brushtails also taken there. Long-nosed bandicoots (''Perameles nasuta'') were regular supplemental prey in northeastern New South Wales.Harder, M. (2000). ''Diet and breeding biology of the Wedge-tailed Eagle Aquila audax at three nests in northeastern New South Wales''. Corella, 24(1/2), 1–5. Other notable marsupials known to fall prey to wedge-tailed eagles include adults of the following: koalas (''Phascolarctos cinereus''), quokkas (''Setonix brachyurus''), eastern quoll, eastern (''Dasyurus viverrinus''), western quoll, western (''Dasyurus geoffroii'') and tiger quolls (''Dasyurus maculatus''), Tasmanian devils (''Sarcophilus harrisii''), Macrotis, bilbies, numbats (''Myrmecobius fasciatus''), common wombats (''Vombatus ursinus''), southern greater gliders (''Petauroides volans'') and Long-nosed potoroo, potoroos.O’Sullivan, T. (2014). ''Breeding behaviour and success of the Tasmanian wedge-tailed eagle (Aquila audax fleayi)'' (Doctoral dissertation, University of Tasmania). With relative infrequency, other classes of mammals, beyond leporids and marsupials, may be taken opportunistically by wedge-tailed eagles. At least two species each of Pteropus, flying foxes and wattled bats are included in the prey spectrum. Occasionally, an eagle may take a monotreme including both the platypus (''Ornithorhynchus anatinus'') and the short-beaked echidna (''Tachyglossus aculeatus''). Several species of rat are readily taken and even the house mouse (''Mus musculus''), likely the smallest mammalian prey known for wedge-tailed eagles at around in weight. Although rare, a dingo (''Canis lupus dingo'') may taken by a wedge-tailed eagle at times, mostly pups, or carrion but sometimes a pair of eagles can kill adults too. Beyond sheep, pigs and infrequently young goats (''Capra hircus''), other Even-toed ungulate, ungulate prey, entirely introduced by man into the Australasian region, is eaten exclusively as carrion so far as is known, including cattle (''Bos primigenius taurus'') (despite claims that these eagles have killed young calves, which is possible, they've only ever been witnessed feeding on Placental expulsion, afterbirths and not harming calves), Javan rusa (''Rusa timorensis'') in New Guinea and sambar deer (Rusa unicolor) in northern Victoria (Australia), Victoria and water buffalo, swamp buffalo (''Bubalus bubalis'') in the Northern Territory.Corbett, L., Hertog, T., & Estbergs, J. (2014). ''Diet of 25 sympatric raptors at Kapalga, Northern Territory, Australia 1979–89, with data on prey availability''. Corella, 38, 81–94.Debus, S. J. S., & Rose, A. B. (1999). ''Notes on the diet of the wedge-tailed eagle Aquila audax''. Australian Bird Watcher, 18(1), 38–41. In one instance, a young girl was apparently subject to a brief attack by a wedge-tailed eagle, in what was likely an attempted act of predation, near her rural home but the attack was abandoned by the eagle. It has been noted that some different species of large eagles are thought to occasionally attack children as prey, though among extant species only the crowned eagle and martial eagle, both in Africa, are thought to have successfully carried out rare acts of predation on human children.


Birds

Birds take a clearly secondary position to mammals when importance and especially prey weight are concerned, however the wedge-tailed eagle has some fondness clearly for avian prey. With more than 100 prey species included in the prey spectrum, birds are the most diverse class of prey taken by these eagles. Generally, the predation of birds seems to be highly opportunistic and no one type of bird reliably dominates the eagle's diet. However certain species, probably due to their commonality in eagle territories and perhaps vulnerability through their own behaviour that seem to be taken most often. These consist of ''Corvus'' species, especially Little raven, little (''Corvus mellori'') and Australian ravens (''Corvus coronoides''), weighing a mean between species of around when taken, Australian magpies (''Gymnorhina tibicen''), Australian wood duck (''Chenonetta jubata''), galah (''Eolophus roseicapilla''), larger cockatoos and smaller Psittaculidae, parakeets and parrots.Dennis, T. E. (2006). ''Status and distribution of the Wedge-tailed Eagle on the Fleurieu Peninsula, South Australia, in 2005''. South Australian Ornithologist, 35(1/2), 38.Fulton, G. R. (2019). ''Additions to prey taken by Wedge-tailed Eagles' Aquila audax'after release of Rabbit Oryctolagus cuniculus haemorrhagic disease (Rabbit Calicivirus) in 1996''. Australian Field Ornithology, 36, 11–12. On Kangaroo Island, Australian and little ravens together constituted 19% of the diet. In Canberra, fairly prominent numbers of magpies, wood ducks, galahs and Eastern rosella, eastern (''Platycercus eximius'') and crimson rosellas (''Platycercus elegans'') are known to be taken, these collectively forming up to about 25% of the diet by number. In the Perth region, birds were taken amply, especially the Australian raven at 12.6% of prey remains and 4.7% of the biomass, with birds constituting just shy of 25% of the diet. Elsewhere in
Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to t ...
, a similar percentage of the diet is made up of by birds, mostly the same species with some number of Australian ringnecks (''Barnardius zonarius'') and Baudin's black cockatoos (''Zanda baudinii'') as well. Peculiarly, one study found that among a large sample of 1826 prey items in the Northern Territory that the most often identified prey species was the tiny budgerigar (''Melopsittacus undulatus''), at one of the smallest avian prey species for this eagle. In a single study from the Fleurieu Peninsula, birds were the majority of prey for wedge-tailed eagles, at 62.5%, mostly ''Corvus'' followed by wood duck, galah and magpies. Other assorted avian prey include several species of waterfowl, including several ducks as well as Black swan, swans and Magpie goose, geese, and a fairly strong frequency of attacks on large Rail (bird), rails, such as Australasian swamphen, swamphens, Dusky moorhen, moorhens, Tribonyx, native-hens and Eurasian coot, coots. Additionally, wedge-tailed eagles may take Australian brush turkeys (''Alectura lathami'') and malleefowl (''Leipoa ocellata''), Stubble quail, quail, pigeons and doves, Tawny frogmouth, frogmouths and Australian owlet-nightjar, owlet-nightjars, Pallid cuckoo, cuckoos, buttonquails, Banded stilt, stilts, lapwings, plains-wanderers (''Pedionomus torquatus''), Bush thick-knee, thick-knees, Silver gull, gulls, Great-winged petrel, petrels, cormorants, herons, ibises and Royal spoonbill, spoonbills, Crane (bird), cranes, other birds of prey, Laughing kookaburra, kingfishers, honeyeaters, Chestnut-breasted quail-thrush, quail-thrushes, Grey shrikethrush, whistlers, Australian magpie-lark, monarch flycatchers, White-winged chough, mudnesters, Artamidae, artamids, Eurasian blackbird, true thrushes, Brown songlark, grass warblers, Common starling, starlings and Richard's pipit, pipits. The smallest avian prey attributed to wedge-tailed eagles is the zebra finch (''Taeniopygia guttata''). Particularly large birds are sometimes taken of a few species. When it comes to the emu (''Dromaius novaehollandiae''), Australia's tallest and second heaviest bird, wedge-tailed eagles normally attack the small young but are capable of attacking adult emus more than 10 times their own weight.Davies, S. J., & Bamford, M. (2002). ''Ratites and Tinamous: Tinamidae, Rheidae, Dromaiidae, Casuariidae, Apterygidae, Struthionidae''. Oxford University Press. Two estimates estimated the typical body mass of emus attacked were merely , respectively, against an average of for adult emu. As much as 4% of the diet of wedge-tailed eagles can consist of emu chicks. Some Australia's largest flying birds are also included in the wedge-tailed eagle's prey spectrum. These include the black swan (''Cygnus atratus''), estimated to weigh when taken, black-necked stork (''Ephippiorhynchus asiaticus''), which weighs at least , and brolga (''Antigone rubicunda''), arguably Australia's largest resident flying species of bird at a mean of . An unusually close feeding association with a very large bird is with the Australian bustard (''Ardeotis australis'') in northwestern Queensland, where bustards were found to account for 13.4% of the pellet contents and 23% of prey biomass. This study calculated the mean weight of bustards taken as , indicating that the eagles were selectively predating the much larger male bustards.


Reptiles and other prey

When selecting reptiles as prey, wedge-tailed eagles by far are most likely to pursue lizards. The range of lizards they may prey upon is highly diverse in size and nature, with somewhere between 20 and 30 species known in the prey spectrum.Cook, W. E. (1987). ''Amphibians and reptiles: predators and prey. Amphibians and birds. Bibliography of Herptological References in Australian Ornithological Journals''. Smithsonian Herptological Information Service, No. 71. The most preferred reptilian prey by far is Pogona, bearded dragons. Despite the small size of this prey relative to most mammalian prey, they can be key to survivorship in more arid vicinities such as central and western Australia where there is less diverse prey to pick from. In video monitored prey deliveries at Fowlers Gap Arid Zone Research Station, central bearded dragons (''Pogona vitticeps'') dominated the prey composition, making up 68.2% of 110 prey deliveries and the only known instance of reptiles forming the bulk of wedge-tailed eagles diets. A different study from prey remains and pellets found the central bearded dragon to comprise 28.6% of the diet among 192 prey items. In south-central Queensland, the bearded dragon was the leading prey species by number, making up 26.9% of 729 prey items. In northeastern New South Wales, the eastern bearded dragon (''Pogona barbata'') was the second most numerous prey species behind the rabbit, at 16.6% of the diet. The bearded dragons when taken by wedge-tailed eagles have had an estimated body mass ranging from . They also prey on jacky dragons. Larger lizards are readily taken as well given the opportunity. Skinks are occasional supplemental prey, Tiliqua scincoides, common blue-tongued skink (''Tiliqua scincoides'') at around can make up around 5% of the diet (in northeast New South Wales), while the Centralian blue-tongued skink (''Tiliqua multifasciata'') was quite prominent in the diet in the Northern Territory.Meiri, S. (2010). ''Length–weight allometries in lizards''. Journal of Zoology, 281(3), 218–226. In Western Australia, Tiliqua rugosa, shingleback skink (''Tiliqua rugosa'') and somewhat smaller Western blue-tongued lizard, western blue-tongued skink (''Tiliqua occipitalis'') collectively comprised about 7.5% of the diet. Much bigger lizards are sometimes taken, namely monitor lizards. Around 20% of the 231 prey items of in a Western Australian study was found to be monitor lizards, mostly yellow-spotted monitors (''Varanus panoptes'') with some sand goannas (''Varanus gouldii''). Adult rosenberg's monitors (''Varanus rosenbergi''), weighing around can be also taken. Even lace monitors (''Varanus varius''), which weighs on average adults, can sometimes taken by wedge-tailed eagles. Contrarily, lizards down to the size of a pygmy spiny-tailed skink (''Egernia depressa'') and a thorny devil (''Moloch horridus'') may be taken. Beyond lizards, wedge-tailed eagles seldom seem to hunt other types of reptiles. They hunt a few species of snakes, mostly Venomous snake, venomous species as these are prevalent in Australia. Snakes known to be included in the diet including tiger snakes (''Notechis scutatus''), eastern brown snake (''Pseudonaja textilis''), ringed brown snake (''Pseudonaja modesta''), bandy-bandy (''Vermicella annulata''), yellow-faced whipsnake (''Demansia psammophis''), red-bellied black snake (''Pseudechis porphyriacus'') and brown tree snake (''Boiga irregularis''). Eastern long-necked turtle (''Chelodina longicollis'') have been claimed as prey in one report although any other confirmed cases of predation on turtles by this species are not known. Notably, there are no reports of wedge-tailed eagles attacking Pythonidae, pythons despite several species being present in Australia nor on crocodiles and perhaps these are the only predators too formidable to be attacked, both of these reptiles can attain extremely large sizes. Predation on frogs or other amphibians is almost unheard of for wedge-tailed eagles, however, based on toxicity reports in eagles, they may consume invasive cane toads (''Rhinella marina'') from time to time. Similarly rare in the species’ diet is fish, although common carp (''Cyprinus carpio'') and Achoerodus gouldii, western blue groper (''Achoerodus gouldii'') have been documented as prey. Occasionally, wedge-tailed eagles may even attack insects such as ''Psaltoda moerens'' cicadas and ''Heteronychus arator'' beetles. Truly exceptional is in the Northern Territory, where a large percentage of 1826 prey items was made up of by insects including unidentified Orthoptera, at about 10.8% of the diet, unidentified beetles, at about 8.4%, as well as some numbers of ants. Why and how they capture a profusion of insects locally is not clear, and they may be often from the stomachs of other prey or even byproduct from the captures of other prey or from the bodies of carcasses.


Interspecific predatory relationships

The wedge-tailed eagle occupies a fairly unique niche relative to other ''Aquila''. While primarily continental in distribution, it is distributed well apart from most related species, whereas most ''Aquila'' are distributed in Eurasia or Africa and face considerable competition over resources, enabling certain specializations of most species in habitat or microhabitat, morphology and behaviours and often life history, including nesting grounds and often foods. The wedge-tailed eagle has the ability to exploit a more catholic variation of both prey and habitat since it exists with relatively fewer competing species. The most considerable potential competition comes in the two other eagles regularly distributed in Australia, the
little eagle The little eagle (''Hieraaetus morphnoides'') is a very small eagle native to Australia, measuring 45–55 cm (17–21.5 inches) in length and weighing 815 g (1.8 lb), roughly the size of a peregrine falcon. It tends to inhabit open wo ...
and
white-bellied sea eagle The white-bellied sea eagle (''Haliaeetus leucogaster''), 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 t ...
. The little eagle has a few ecological similarities to the wedge-tailed eagle. It is also something of a habitat generalist, although it is found somewhat scarcely in more arid vicinity, high elevation areas and varied semi-open forest than the wedge-tailed eagle. Like the wedge-tailed eagle, the little eagle has in recent decades become a somewhat specialized predator of European rabbits. However, the size difference is extreme between the wedge-tailed and little eagles, with the earlier over four times heavier than the latter, and the little eagle as expected exploits a lower trophic level relative to its more powerful competitor. As in other areas where booted eagles and sea eagles have abutting ranges, sometimes wedge-tailed eagles compete with white-bellied sea eagles. One key difference from elsewhere where competition sometimes occurs such as the golden eagle with the
white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
(''Haliaeetus albicilla'') in Eurasia and the
bald eagle The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies the same niche as ...
(''Haliaeetus leucocephalus'') in North America, both of which are slightly heavier than the golden, is that the white-bellied sea eagle is the slightly smaller species than the wedge-tailed eagle, potentially giving the latter a more pronounced competitive edge.Palmer, R. S. (Ed.). (1988). ''Handbook of North American Birds Volume VI: Diurnal Raptors (Part 1)''. Yale University Press. However, the white-bellied sea eagle clearly does not shy away from contentious border disputes with wedge-tailed eagles and the two species can often be seen be seen readily attacking each other, occasionally in talon grappling and sometimes cartwheeling attacks on one another. However, the ecological effect of interspecific competition of the two species is not clear. Although the wedge-tailed eagle is considered the dominant species of the two, they clearly do not take the presence of white-bellied sea eagles lightly and some authors feel they may avoid nesting near them.Olsen, J., Debus, S. J., Rose, A. B., & Judge, D. (2013). ''Diets of White-bellied Sea-Eagles Haliaeetus leucogaster and Whistling Kites Haliastur sphenurus breeding near Canberra, 2003–2008''. Corella, 37, 13–18. Clearly there is ample partitioning between the wedge-tailed and white-bellied sea eagles, the latter adapted to mostly open
wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...
s and
coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...
s and, while also a dietary generalist, they tend to derive most of their diet from fish, water birds and other wetland-dwelling prey, and they seldom compete directly for prey such as mammals with wedge-tailed eagles. Most other diurnal raptors that reside in Australia are considerably smaller and seldom can be said to present great competition to the wedge-tailed eagles, although some such as swamp harriers (''Circus approximans''), black-breasted kites and grey goshawks (''Accipiter novaehollandiae'') are relatively large for their taxon and powerful predators in their own rights. In one instance, a square-tailed kite (''Lophoictinia isura'') was observed to engage in an apparent territorial fight with a wedge-tailed eagle, including talon-grappling. When it comes to carrion, wedge-tailed eagles tend to dominate other predators, especially most birds, with most kites, other assorted raptors and some large passerine birds, mainly ''Corvus'' species and butcherbirds, coming to dead animals including roadkills. However, heavier terrestrial meat-eaters can hold their own at times against wedge-tailed eagles, namely red foxes, dingos, monitor lizards and Tasmanian devils, despite all these species sometimes turning up as prey of these eagles as well. Sometimes the wedge-tailed eagle will readily rob various other raptors of their prey, including little eagles, white-bellied sea eagles and brown falcons (''Falco berigora''). Wedge-tailed eagles will opportunistically prey on other birds of prey. They share this aptitude they share with other large eagles in different parts of the world such as golden eagles, although such acts are relatively infrequent, it is clear that the wedge-tailed eagle is considered a primary threat by many raptors based on witnessed attacks by eagles on them and the mobbing behaviour of other raptors.Ley, A. (2006). ''Wedge-tailed Eagles preying on other raptors''. Boobook 24, 42. Among the other birds of prey known to occasionally fall prey to these eagles are little eagles, collared sparrowhawks (''Accipiter cirrocephalus''), grey goshawks, brown goshawks (''Accipiter fasciatus''), Pacific bazas (''Aviceda subcristata''), black-breasted buzzards, peregrine falcons (''Falco peregrinus''), Australian hobbys (''Falco longipennis''), black falcons (''Falco subniger''), brown falcons and Nankeen kestrels (''Falco cenchroides''). Occasionally owls are also included in the prey spectrum when an opportunity arises, including barn owls (''Tyto alba''), southern boobooks (''Ninox boobook'') and even powerful owls (''Ninox strenua''). Wedge-tailed eagles are apex predators and have no well-documented predators, although presumably they have some nest predators, likely including ravens and currawongs, especially when displaced by human disturbance from their nests. Occasionally, these eagles may possibly risk injury or death in conflicts against other powerful predators and scavengers, such as dingos, quolls, Tasmanian devils, goannas and snakes, but no such verified instances seem to be known in literature, and man is considered to be the wedge-tailed eagle's only true predator. Occasionally they may be injured and even killed via intra- and interspecies territorial conflicts and Mobbing (animal behavior), mobbing by other birds of prey, especially stooping peregrine falcons which have successfully knocked wedge-tailed eagles out of the sky, with a force known to kill both golden and bald eagles in other parts of the world. Due to the formidable aerial attack of the peregrine, it may be the only raptor besides the white-bellied sea eagle that wedge-tailed eagles may avoid nesting near. Most of the large falcons, including peregrine, brown and black falcons, and at times large owls nest in unused or abandoned wedge-tailed eagle nests.


Breeding

The breeding season is from July to December through much of range, in New Guinea apparently from May on. They have a distinct tendency that lay earlier in the more northerly part of the range. For instance, in northeastern Australia laying has been recorded in January and February and in Tasmania in September. In western Australia, breeding depends on food and during drought periods there may be no nesting for up to 4 years. Adult wedge-tailed eagles are usually solitary or occur in pairs but immatures are more gregarious. 10–15 May rest or soar together or even hunt together and up to 40 recorded at carcasses. Mated adults perform mutual soaring, undulating dives, and tandem flights with rolling and foot-touching. The female may appear to ignore or more often turn over and present claws when a male is displaying. As possibly part of courtship feedings on pairs have taken place away from the nest and sharing of a cache of food may occur.Olsen, J. & Trost, S. (2014). ''Courtship feeding in Wedge-tailed Eagles''. Boobook, 32: 12–13. Preening, Allopreening occurs occasionally between pairs but is seldom observed, although at times has been considered a “regular” part of the courtship process. Contrary to historical accounts, wedge-tailed eagles seldom engage in an elaborate courtship display and will instead generally try to conserve energy, instead devoting their energy for the upcoming trying breeding season along with territorial exclusions of conspecifics and obtaining food. Mating tends to occur on a bare branch or dead tree in the nest area, and may continue into the nestling period.Allott, M., Allott, M., & Hatchett, N. (2006). ''The breeding cycle of a pair of wedge-tailed eagles Aquila audax in South-east Queensland''. Sunbird: Journal of the Queensland Ornithological Society. 36(1), 37–41. Contrary to old accounts, the species does not mate in flight. In the pre-laying phase, mating was recorded to be preceded or accompanied by loud, slow yelping, but in the nestling period, the pair alighted together and the male mounted without preliminaries and a silent copulation lasted for one minute.


Territories and home ranges

Territories are established with aerial displays, which can include high circling by one or both of pair, sometimes interspersed with flight rolls and talon presenting. Most of the time, wedge-tailed eagles typically respect pair boundaries and can limit territorial behaviour to mild aerial flights, with the intruders usually giving the ground to incumbents. Violence is usually avoided but sometimes the most heated territorial disputes can escalate to deaths. Sometimes the displaying eagle may engage in a steep dive on part closed wings followed by an upwards swoop, later may escalate into spectacular sky dance with undulations; they may too Aerobatic maneuver, loop-the-loop. Cartwheeling is typically rare but in one case, three immatures mock dived at each other, two birds interlocked and cartwheeled several times before breaking away. No cartwheeling or talon grappling has been reported between members of a mated pair, but occasionally reported as used against intruding eagles.Cherriman, S. C., Foster, A., & Debus, S. J. (2009). ''Supplementary Notes on the Breeding Behaviour of Wedge-tailed Eagles Aquila audax''. Australian Field Ornithology, 26(4), 142–147. Aerial displays may go on for a while normally early in the breeding season, between 3 months and 3 weeks prior to egg laying. Territorial attacks by male wedge-tailed eagles may be against any encountered intruding eagles, including both male and female intruders, while female eagles engage in less territorial attacks and when they do, it is exclusively against other females. Territorial aggression can extend towards hang gliders and aircraft, advances noisily, bill open and talons extended until flying just above and behind or slightly ahead of pilot then swoops repeatedly after making contact with the hang-glider. A core of some radius around the nest is most fervently defended. Foraging ranges from nest may be up to about . Foraging ranges on breeding home ranges may be around for males and for females in arid central western Australia. Range sizes of pair members vary greatly based on topography, habitat and prey access. Several reported densities of 3–6 pairs per , others of 7–12 pairs per . When rabbits were in plague type numbers, pairs may nest as close apart and 4 others no more than from those two pairs. In semi-arid areas of New South Wales near Menindee, New South Wales, Menindee densities were found to be about a pair per , 10–12 pairs in good years, 3 in drought years.Robertson, G. (1987). ''Effects of drought on a breeding population of Wedge-tailed Eagles Aquila audax''. Emu 87, 220–223. doi:10.1071/MU9870220 Not far from that in Mutawintji National Park density was around a pair per . Much higher densities in this semi-arid zone of western New South Wales, with a pair per , against around a pair per in other arid zones. In Western Australia, arid areas had a nearest neighbor distance of while those nesting in Mesic habitat, mesic areas had a distance of .Cherriman, S. C., Fleming, P. A., Shephard, J. M., & Olsen, P. D. (2021). ''Climate influences productivity but not breeding density of wedge‐tailed eagles Aquila audax in arid and mesic Western Australia''. Austral Ecology. At Fowlers Gap Arid Zone Research Station, Fowlers Gap, there were 9–10 pairs per . Near Canberra, around 37 pairs were reported in an area of , including some unusually as close as to Road surface, paved roads and as close as from suburban spots. This contrasts strongly with 36 years prior, when few nests were near human-altered areas and the amount of pairs in the same area was about 32.Fuentes, E., Olsen, J., & Rose, A. B. (2007). ''Diet, occupancy and breeding success of Wedge-tailed Eagles Aquila audax near Canberra, Australia, 2002–2003: four decades after Leopold and Wolfe''. Corella, 31: 65–73.Leopold, A. S., & Wolfe, T. O. (1970). ''Food habits of nesting Wedge-tailed Eagles, Aquila audax, in south-eastern Australia''. CSIRO Wildlife Research, 15(1): 1–17. In the Fleurieu Peninsula in South Australia during the early to mid 2000s, there was a pair per , active nest sites were apart, while the average home range around the nest is roughly. Resurvey efforts a dozen years later in Fleurieu Peninsula found a more populous population, resulting in a home range estimated at with some active nests as close as apart.Rowe E., Brinsley, R., & Dennis, T. (2018). ''A review of Wedge-tailed Eagle population stability in the Fleurieu Peninsula region of South Australia in 2017''. South Australian Ornithologist, 43: 1–2. In the Perth area, it was projected that the mean home range was about . Meanwhile, in southern Victoria the nearest neighbor distance of breeding pairs was while mean territory size was calculated at .Foster, A., & Wallis, R. (2010). ''Nest-site characteristics of the Wedge-tailed Eagle Aquila audax in southern Victoria''. Corella, 34, 36–44.


Nests

Both sexes may participate in building the nest but the female takes the greater share, often standing in the middle and building outwards. Often wedge-tailed eagles build alternative nest, up to 2 to 3 per territory, though when undisturbed uses the same general site repeatedly. In Tasmania, territories held a mean of 1.4 nests. The nest is usually either substantial or massive. The nest is a structure of sticks ranging across and deep when first build but with repeated additions up to across and nearly deep. The interior nest cup is commonly around across about deep. Four studies found the diameter of nests to average from as little as and as much as and in depth from as little as to as much as . Generally speaking in woodland or forest edge areas, nests tend to be larger, while those in sparser, more arid areas tend to have characteristically smaller nests, as they have lesser access to nest building materials.Weirsma, J., & Koch, A. J. (2012). ''Using surveys of nest characteristics to assess the breeding activity of the Tasmanian wedge-tailed eagle''. Corella, 36(2): 38–44. Good sized nests can weigh well over . Nests are usually lined with green leaves and twigs, a common practice in accipitrids. Infrequently, they may use an old nest built by another accipitrid, namely whistling kites (''Haliastur sphenurus'') and white-bellied sea eagles, with the earlier's nests apparently added to in order to enlargen it. Ideally the nest is located at above the ground on a lateral branch or main fork of lone or forest tree; in taller trees, nests can be as much as high to the opposite extreme down in lower ground or even on rocks or ground trees are scarce. In a few studies different areas of New South Wales, the mean nest height was from and were often relatively close to Land development, human development. Two results in southern Victoria found mean nest heights to be . In often particularly arid Western Australia, mean nest heights were reportedly lower, averaging at . Detailed study in Western Australia found nest heights were higher in Mediterranean forests, woodlands, and scrub, Mediterranean scrubland at against in the Semi-arid climate, arid zone, but nest height seemed to not have bearing on occupancy or success, territoriality kept the population regulated within the habitats.Ridpath, M. G., & Brooker, M. G. (1987). ''Sites and spacing of nests as determinants of Wedge-tailed Eagle breeding in arid Western Australia''. Emu, 87(3), 143–149. Occasionally they may nest in dwarf trees at as low as . Favoured nesting trees include many ''
Eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as ...
'' and ''Casuarina'' species, as well as ''Corymbia'', ''
Callitris ''Callitris'' is a genus of coniferous trees in the Cupressaceae (cypress family). There are 16 recognized species in the genus, of which 13 are native to Australia and the other three (''C. neocaledonica, C. sulcata'' and ''C. p ...
'' and ''Syncarpia glomulifera'' while in inland areas more often ''
Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus nam ...
'', ''Flindersia'' as well as ''Hakea leucoptera'' and ''Grevillea striata''. The amount of ''Eucalyptus'' tree species used by wedge-tailed eagles is extremely diverse and ultimately the species seem to have no strong overall preferences regarding tree species, more importantly seeking a given tree of ample height and considerable broadness. Furthermore, nest trees are often on slightly elevated ground above the mean ground level, presumably in order to offer a more commanding view of the surrounding environment. Additionally, trees with fewer lower branches may be preferred. Nests are seldom on
dead trees ''Dead Trees'' is the fifth studio album by post-hardcore band From First to Last, released April 23, 2015, via Sumerian Records. It is the first and only release to feature vocalist Spencer Sotelo (singer of progressive metal band Periphery), Ta ...
, usually this occurs where there is an absence of leafy ones. While Australian nests can be in quite varied surroundings, Tasmanian nests are almost exclusively within well forested areas. Forest type nests tend to have a sparse, open understory and woodlands or nearby glades often are considered perhaps more attractive to the species. In desert-type areas, they may nest on a hill or a rise, and in addition sometimes cliff ledges, or among Rock (geology), rocks, and even on ground in both islands and desert-like areas, preferably in areas difficult for or inaccessible to humans. Additionally they've been known to nest on Transmission tower, power pylons and Utility pole, telegraph poles. Other smaller animals may nest among the sticks at the base of active wedge-tailed eagle nests such as finches, pardalotes and even Phalangeriformes, possums (which more so than the small birds are presumably vulnerable to the eagles if caught in the open), perhaps gaining some protection from the presence of the eagles. This is a not unknown phenomenon in many bird assemblages for small birds to gain incidental protection from strong raptors. Other species, such as Pacific black ducks (''Anas superciliosa''), falcons and owls, may also benefit by utilizing unused nests for their own breeding purposes, although typically only the falcons usually use them with relative regularity.


Development of young and parental behaviour

Clutch size is usually just one or two but sometimes to 4. About 80% of nests where eagles have managed to lay eggs contain two eggs. Mean clutch size is apparently somewhat higher in the western part of the range.Olsen, P., & Marples, T. G. (1993). ''Geographic-variation in egg size, clutch size and date of laying of Australian raptors (Falconiformes and Strigiformes)''. Emu, 93(3), 167–179. The female lays multi-egg clutches by some 3 days or so apart. The eggs are buff or white in colour, often appearing heavily blotched all over with purple-brown, red-brown or lavender, or more sparsely spotted with reddish brown. The amount of spotting is quite variable on eggs even within a single clutch, some being heavily marked, others hardly at all, and at times concentrated on the pointier end of the egg. When freshly laid, the eggs are glossy but they become more matte and brittle with age. Eggs may range in height from , averaging in a sample of 54, by , averaging .White, H. L. (1918). ''Notes upon eggs of the Wedge-tailed Eagle (Uroaetus audax)''. Emu-Austral Ornithology, 17(3), 149–150. Each egg normally weighs about , the equivalent to about three chicken eggs or about 3% of the female eagle's body weight, 10% when the clutch number is 3, which is typical for an ''Aquila'' eagle but a small percentage relative to smaller raptors. The larger eagles of Tasmania lay larger eggs on average reportedly. Wedge-tailed eagles sometimes lay runt eggs in nests in normal nests, in a condition apparently unique for Australian raptors, and these reportedly never hatch. If a clutch is lost or stolen early in incubation, some pairs have been documented to replace it, being able to do so about a month later. The incubation stage lasts for 42–48 days. The female of the pair either primarily or entirely incubates on her own and, like many eagles, she is a tight sitter.Fleay, D. (1952). ''With a wedge-tailed eagle at the nest''. Emu-Austral Ornithology, 52(1), 1–16. However, the male will incubate at times as well, at least up to an hour at a time. In New South Wales, the male was found to incubate for 16–20% of daylight during which the nest was unguarded for 3–13% of the day. In some cases, male incubation may vary from 1–6% of daylight to as much as 38% of daylight with shifts in extreme lasting up to 6 hours. Male primarily delivers prey to the nest during incubation (not prior), up about to the stage where the eaglet(s) can be left unattended. The chicks are covered in white down up at first and are expectedly Altriciality, semi-altricial. At about 12 days or so, a slightly greyer down develops and this ultimately becomes the woolly undercoat for the contour feathers. Within a couple days later, the black quills of the primaries often start to emerge, and can start to stand and move around the nest. At 28 days, the eaglets are showing their upper wing coverts increasingly through the down. At 35 days of age, some darker feathers are appearing on areas such as the breast, belly, mantle, back and head; mostly these are evident as a few dark rufous feathers poking through the head down while at this age they show a short buff-tipped tail. They are partially feathered up to 37 days and nearly completely feathered by 49 days. At around 37 days, they can attempt to tear food from carcass in the nests without much success. From 50 days onwards, the eaglet(s) play a good deal, pouncing on sticks and degree around the nest. Around this age, they are markedly almost full feathered but for the wing and tail, neither of which has reached its full length, and they may have a few wisps of down about their crown or neck. Weight increases are from about at 15 days with a notably increase in robustness to at 29 days, to at 49 days, making more rapid feathering growth thereafter primarily while body size growth slows considerably. Sibling aggression tends to begin at when around when the eaglets are two weeks of age, as in many birds of prey, the younger sibling(s) in wedge-tailed eagles are not infrequently runts. Unlike related eagles, there is some evidence that higher parental attendance limits instances of aggression, whereas in other eagles this occurs often in the parent's presence. In all eagles, the parent eagles make no attempt to intercede when runting or aggression between siblings occurs. Siblicide occurs occasionally in this species and it is considered a “facultative cainist” rather than an obligate one, meaning siblicide occurs occasionally and as conditions dictate as opposed to some eagles where it occurs almost invariably. Reportedly, in Tasmania, a study reported that all but 2% of recorded nests managed to produce two fledglings, implying extremely low rates of siblicide in this race. The female broods attentively at first but then decreases after the second or third week and then ceases brooding almost entirely by 30 days, even at night. For 40 or more days, the female continues to assist the young with feeding, typically from the male's prey deliveries though the female may resume hunting after nest attendance drops. Potential predators such as goannas are struck when found to be approaching the nest, although the eagles usually abandon the nest when a human approaches. Repeated intrusions and noisy disturbances may have a net negative effect such as on Tasmanian wedge-tailed eagles, as these factors often lead to nest failure. In one case in South Australia, the removal of a dead tree in the vicinity of a wedge-tailed eagle nest resulted in full abandonment of the nest by the parents. The female may too continue to bring green leaves to a late stages, doing so more often in a spell of wet weather. During times of plenty, Hoarding (animal behavior), caches can sometimes form around the nest, with much prey left partially or entirely uneaten. Upon leaving the nest at 11 to 12 weeks of age, the young eagles are not strong fliers for another 20 days or so, but can competent flying can be by about 90 days of ages, though full feather development is not until 120 days. Fledgling occurs at 67 to 95 days, typically being less than 90 days and averaging roughly around 79 days. Dependence lasts up to 4 to 6 months after fledging, with the juvenile eagles which overstay rarely known to be an occasionally fatal danger to the subsequent chick hatched to their parents. During the later periods of fledgling, interactions are restricted to brief prey deliveries and the parent eagles stop feeding the young eagle(s), forcing to go forage elsewhere for foods. A study of post-fledgling dispersal found in one case that a young eagle covered only a range, with a maximum covered in a week of . Most recoveries in one banding study were distributed under from their original banding site, mostly as fledgling age juveniles, but some meandered up to away. After dispersal, young eagles are floaters up until their 4th or 5th year, typically avoiding the territories of adults and searching out feeding opportunities. Up to two-thirds of young wedge-tailed eagles may die some time between fledgling and when they are 3–5 years but adults often have quite low mortality rates and can live the better part of a half century. First breeding is typically at 6 or 7 years old. Lifespans of wedge-tailed eagles in the wild are poorly known, with the maximum recorded in one banding study being merely 9 years, quite a paltry age compared to other large eagles, and it is quite conceivable that eagles who survive to maturity not infrequently live around twice that long or more. In captivity, the species has been known to live to around 40 years of age.


Breeding success

Only one young is typically produced from a clutch of two but occasionally two fledglings may occur. The breeding success rates of the species are variable. In overall studies, at least 52 to 90% of breeding pairs managed to produce a fledgling, with further projected numbers from this of 0.2–0.5 fledgling per pair, 0.7–1.2 fledgling per clutch and 1.1–1.3 fledgling per brood. In southwestern Australia, from 0.7 to 1.2 young are fledged per clutch laid, 0.19–0.46 young per pair per year. In south-central Queensland, fledgling productivity was 1.1 per young to pairs that laid eggs. Northern New South Wales eagles were able to produce 0.8 young per pair from 2005 to 2006 while 0.89 and 0.64 fledged young per pair per year was the fledgling rate in central and western New South Wales, respectively.Davey, C., & Pech, R. (2004). ''Effect of reduced rabbit numbers on the reproductive success of Wedge-tailed Eagles Aquila audax in central-western New South Wales''. Boobook, 22: 37–38. In a further study in New South Wales at Burrendong Dam, from 1993 to 2003, 15 pairs produced an average of one fledgling per territory but 1998 due to drought conditions, the rate was only 0.4 chick per territory. Within Kinchega National Park, however, the rate of 0.99 young per pair was fairly consistent regardless of climatic conditions. In the Australian Capital Territory, pairs were said to produce 1.1 fledglings per pair. In southeastern Australia, from 0.9 to 1.5 young per clutch are laid, with 0.6–1.0 young per pair per year. In Tasmania, from 0.64 to 0.8 young are fledged per clutch laid, 1.07 per successful nest. 0.91 young were produced per pair in southern South Australia or 1.1 fledglings per successful nesting attempt. Subsequent research in South Australia found 38 successfully fledged young with 10 pairs or 26% producing two fledglings and that production was 1.1 per occupied territory and 1.3 per successful pair. 0.73 fledglings were produced pair per year in south-west
Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to t ...
. Western Australian eagles produced 0.92 fledged young per clutch laid and 1.1 young per successful nest.Cherriman, S. C. (2013). ''Nest-site characteristics and breeding productivity of wedge-tailed eagles (Aquila audax) near Perth, Western Australia''. Amytornis, 5, 23–28. During periods of drought in Western Australia, some wedge-tailed eagles may forgo breeding for up to four years.Ridpath, M. G., & Brooker, M. G. (1986). ''The breeding of the Wedge‐tailed Eagle Aquila audax in relation to its food supply in arid Western Australia''. Ibis, 128(2), 177–194. Higher annual rainfall in Western Australia, higher in mesic than arid areas, made a big difference in pair productivity, with 12% of arid zone pairs producing young, or 0.13 fledglings per pair, a very low productivity, while the mesic zone 69% of pairs produced fledglings, or 0.77 fledglings per pair. Generally, wedge-tailed eagles can nest in a variety of habitats and climatic conditions but tend to be slightly less productive in more arid environments. Significant broad-scale control is thought to be unlikely to be harming numbers of young being produced with those with a macropod-based diet perhaps having a richer diet. Like most eagles, wedge-tailed eagles fit the mold rather well of a r/K selection theory, K-selected breeder, i.e. being large, producing fewer young and tending to live relatively long.


Conservation status

In the 1990s, it was estimated broadly that the global population was somewhere between 10,001 and 1,000,000 individuals. As of 2009, Birdlife International listed the total population as only 100,000 mature individuals, possibly conservative and admittedly from poor supporting data.Christidis, L. & Boles, W.E. 2008. ''Systematics and taxonomy of Australian birds''. CSIRO Publishing, Collingwood, Australia. As of that analysis, Birdlife considers the overall population of wedge-tailed eagles to be “possibly increasing”. Generally, the wedge-tailed eagle appears to be quite stable in population. Although wedge-tailed eagles are often scarcer than those large distribution suggests, their total distribution covers more than 10.5 million square kilometers and the population is quite likely within hundreds of thousands. Thinning of Canopy (biology), forest cover, mostly inadvertent provisioning of carrion food sources and, particularly, rabbit introductions may have aided the species, and it may actually be commoner now than before European colonization. Though protected, sometimes wedge-tailed eagles are shot or trapped or killed by poison carcasses set out by farmers many of whom consider it a serious sheep killer. Historically, the wedge-tailed eagle was subject to persecution levels to rival any other eagle in the world. The heavy persecution began in the closing decades of the 19th century, due largely to the establishment of large-scale sheep farming in Australia. One Queensland station claimed to have poisoned 1060 eagles over 8 months in 1903. Laws passed from 1909 to 1925 made it mandatory for landowners and farmers to kill eagles as vermin with enforcement determined by a given region's minister or vermin board, resulting in even more sweeping efforts to destroy the species.Brooker, M. G. (1990). ''Persecution of the Wedge-tailed Eagle''. Birds of Prey. Facts on File, New York, NY USA, 196. Trapping, Steel-jawed rabbit traps were set around carcasses and Heligoland traps could sometimes trap several eagles at once, beyond sustained shooting and poisoning efforts. Between the years 1958 and 1967, 120,000 bounties were paid in merely the states of Queensland and Western Australia on wedge-tailed eagles killed, meaning an average 13,000 were killed each year. Even by 1967 to 1976, likely intentional human killings accounted for 54% of wedge-tailed eagle mortalities in Western Australia, with an estimated 30,000 killed in the year of 1969 throughout Australia. Strong legal protections started in Western Australia in the 1950s increasingly so to the 1970s or later elsewhere, now it is protected and subject to limited persecution throughout. Despite reduced persecution, as of the 1980s, 54% of recovered eagles by the 1980s were killed by human persecution. Despite such stunningly high rates of persecution, the wedge-tailed eagle was remarkably resilient to the haphazard persecution inflicted by humans in a way many other Australian wildlife, especially the regionally endemic mammals, and even other eagles elsewhere often are not. Often the species is less intentionally harmed via human disturbance via land development particularly intensifying agricultural and modern settlements, which can in turn lead to clearing of mature trees, disturbances at the nest and decline of native prey species, all of which have a net negative effect on the wedge-tailed eagles. Eggshell thickness was not significantly decreased by the use of DDT likely due likely to the largely mammal-based diet of the species, whereas raptors which consume birds or fish are disproportionately effected by DDT. On occasional, the species is still subject to Poaching, illegal shootings and poisonings, however persecution of the species is significantly less prevalent in recent decades. Occasionally but not commonly, they are killed by sodium fluoroacetate poisons long used to “control” Australian wildlife, but now generally directed at invasive species such as rabbits, feral pigs and foxes. A list of the main persistent threats in the 21st century to wedge-tailed eagles consists of: destruction of habitat, including
logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. Logging is the beginning of a supply cha ...
, developments including urbanization, wind farm collisions and the disturbance and destruction associated with their construction, increasing density rural human populations, Poaching, illegal persecution in sheep farm areas, drowning in Water tank, open tanks in Aridity, dry Pasture, pastoral zones,
roadkill Roadkill is an animal or animals that have been struck and killed by drivers of motor vehicles on highways. Wildlife-vehicle collisions (WVC) have increasingly been the topic of academic research to understand the causes, and how it can be ...
s (especially while foraging for roadkill carrion), collisions with fences, powerlines and Birdstrike, airplanes, regular electrocutions, poisoning from Bait (luring substance), rabbit baits and other baits and exposure to Lead poisoning, lead and other bullet fragments which may be responsible for some eagle debilitations and deaths. Within the Fleurieu Peninsula, some 1.74 eagles on average are claimed by wind farm turbine collisions. Conservation needs may differ in different habitats, i.e. in more coastal temperate areas, the eagle is reported to have difficulty nesting when hillsides have been cleared of trees, meanwhile inland, they have lesser need of trees in elevated locations because they are more often assisted by thermals. However, they cannot generally persist where leafy trees are Clearcutting, clearcut. Surprising resilience even to drought was found recently in the wedge-tailed eagles in the
Australian Capital Territory The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding township#Aust ...
where pair occupancy remained consistent through drought for wedge-tailed eagles but not for little eagles, but this is may have more to do with the wedge-tails more successful uncoupling from a dependence on declining rabbits as prey than the little eagle. Of 84 eagle deaths or debilitating injuries, 52% were attributable to collisions or electrocutions, 15.5% due to persecution, 11% due to natural causes and 15% were due to unknown causes.


Status in Tasmania

The Tasmanian race of wedge-tailed eagle, ''A. a. fleayi'', is quite restricted in range and habitat, with estimated numbers having gone from 140 pairs in 1980s down to only 60–80 by the mid-1990s. With the island's population numbering quite low and likely continuing its declining, as evidenced by slow replacement of lost pair members, the subspecies is listed as state-endangered. Furthermore, surveys contrasting 1977–1981 with 1998–2001 data found a decline of around 28% in the island's reported number of eagles. Generally Tasmanian wedge-tailed eagles are even less tolerant of human alterations and disturbances near the nest site than mainland wedge-tailed eagles and have more specific habitat requirements. Historically, the same hunting organization in Tasmania that played a large role in the extinction of the thylacine (''Thylacinus cynocephalus'') also intentionally tried to hunt the Tasmanian wedge-tailed eagle into extinction, publicly having erroneously claimed that eagles were non-native in Tasmania, however hunting is unlikely to further continue on a large scale in the state. Where habitat clearance and degradation is extensive in Tasmania, the native prey populations be insufficient to support eagles. Furthermore, the clearing or logging of trees is especially critical in Tasmania, where the eagle is by and large a forest-dependent breeder. Studies indicate that the Tasmanian eagles mostly nest in emergent trees in old-growth native forest exposed to early morning sun and sheltered from prevailing strong winds and cold spring winds, given the more temperate climate here relative to most points in mainland Australia. The subspecies requires forest areas greater than in which to breed and is very prone to desert its nest when disturbed. A predicted change was calculated to the carrying capacity of the Tasmanian forest given current operations is modeled, likely driving the population down. Wind farms in Tasmania are also an occasional threat; although not thought to be a significant source of mortality, wedge-tailed eagles, especially young ones, are less success at avoiding invariably fatal collisions with them than Tasmanian white-bellied sea eagles. Furthermore, of 109 eagle carcasses recovered in Tasmania, all of them had trace levels of lead in their livers or femurs with at least part of the exposure likely from Ammunition, lead ammunition. In addition, like all eagles, Tasmanian wedge-tailed eagles are vulnerable to electrocutions, and collisions with vehicles, overhead wires, and fences and poisonings, largely via illegal killings by poachers of Tasmanian devils and forest ravens (''Corvus tasmanicus''). Efforts are underway to ameliorate the harm being done to Tasmanian wedge-tailed eagles, especially via forestry operations.Mooney, N. J., & Taylor, R. J. (1996). ''Ameliorating the Effects of Forestry Operations on Wedge-tailed Eagles in Tasmania''. Raptors in Human Landscapes: Adaptation to Built and Cultivated Environments, 275. In protected areas, protocols are in place to protect Tasmanian eagle nests and protect them by creating an obligatory nest reserve of at least 10 ha and forestry operation have been restricted during the breeding season to outside a buffer zone of , extending further to if the proposed work is in the line-of-sight of the nesting eagles. About 20% of known pairs are outside protected areas and on private land, so are largely outside the strict legal protection the subspecies has on governmental forest land. Furthermore, researchers are instituting rules to minimize disturbance, limiting breeding surveys to distant observations of whitewash and flattened treetops as proof of nesting and all detailed observations to be obtained after the cessation of breeding activities.


Iconography

The bird is an emblem of the Northern Territory. The Parks and Wildlife Service of the Northern Territory uses the wedge-tailed eagle, superimposed over a map of the Northern Territory, as their emblem. The New South Wales Police Force emblem contains a wedge-tailed eagle in flight, as does the Northern Territory Correctional Services. La Trobe University in Melbourne also uses the wedge-tailed eagle in its corporate logo and coat of arms. The wedge-tailed eagle is also a symbol of the Australian Defence Force, featuring prominently on the :File:Tri-service flag of the Australian Defence Force.gif, ADF Flag, and the Royal Australian Air Force and Australian Air Force Cadets both use a wedge-tailed eagle on their badges. The Royal Australian Air Force has named its airborne early warning and control aircraft after the bird, the Boeing E-7 Wedgetail. Early in 1967, the Australian Army 2nd Cavalry Regiment (Australia), 2nd Cavalry Regiment received its new badge, a wedge-tailed eagle swooping, carrying a lance-bearing the motto "Courage" in its talons. The regiment's mascot is a wedge-tailed eagle named "Courage". Since its formation, there have been two, Courage I and Courage II. In 1997, while on flight training with his handlers, Corporal Courage II refused to cooperate and flew away, not being found for two days following an extensive search. He was charged with being AWOL and reduced to the rank of trooper. He was promoted back to corporal in 1998. The West Coast Eagles AFL football club from
Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to t ...
uses a stylised wedge-tailed eagle as their club emblem. In recent years, they have had a real-life wedge-tailed eagle named "Auzzie" perform tricks before matches.


References


Further reading

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External links

* * * * {{Authority control Aquila (genus), wedge-tailed eagle Eagles, wedge-tailed eagle Birds of Australia Birds of Papua New Guinea Birds of Indonesia Diurnal raptors of Australia Birds described in 1801, wedge-tailed eagle Taxa named by John Latham (ornithologist), wedge-tailed eagle Articles containing video clips