The little eagle (''Hieraaetus morphnoides'') is a very small

eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, just ...

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 The peregrine falcon (''Falco peregrinus''), also known as the peregrine, and historically as the duck hawk in North America, is a Cosmopolitan distribution, cosmopolitan bird of prey (Bird of prey, raptor) in the family (biology), family Falco ...

. It tends to inhabit 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 ...

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 natur ...

and arid regions, shunning dense

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' ...

. It is a near relative of both the

Palearctic The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Sibe ...

booted eagle The booted eagle (''Hieraaetus pennatus'', also classified as ''Aquila pennata'') is a medium-sized mostly migratory bird of prey with a wide distribution in the Palearctic and southern Asia, wintering in the tropics of Africa and Asia, with a ...

and the massive but now

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

Haast's eagle Haast's eagle (''Hieraaetus moorei'') is an extinct species of eagle that once lived in the South Island of New Zealand, commonly accepted to be the pouakai of Māori legend.New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

Taxonomy

John Gould John Gould (; 14 September 1804 – 3 February 1881) was an English ornithologist. He published a number of monographs on birds, illustrated by plates produced by his wife, Elizabeth Gould, and several other artists, including Edward Lear, ...

described the little eagle in 1841. The distinctive

pygmy eagle The pygmy eagle or New Guinea hawk-eagle (''Hieraaetus weiskei'') is a bird of prey found in New Guinea. Its natural habitats are primarily subtropical or tropical moist lowland forest and subtropical or tropical moist montane forest. It was the ...

has long been considered a subspecies, but a 2009 genetic study shows it to be distinctive genetically and warrants species status.

Description

Barrett, et al. (2003), describes the little eagle as a medium-sized bird of prey, between 45 and 55 cm in length. The little eagle is small and stocky with a broad head. It has fully feathered legs and a square-cut, barred tail. Wingspan is about 120 cm with males having longer wings in proportion to their bodies, but being nearly half the weight of females. It is a powerful bird and during flight has strong wing beats, glides on flat wings and soars on slightly raised or flat wings (Marchant and Higgins 1993; Ferguson-Lees and Christie 2001; Olsen and Fuentes 2004; Debus 1998). The little eagle occurs in light and dark colour forms and generally these colours change with age. The most common is the light form which is dark brown occurring on the back and wings with black streaks on the head and neck, and a sandy to pale under body. The dark form of this eagle is similar except the head and under body is usually darker brown or rich rufous. The sexes are similar with females being larger and typically darker. Juveniles are similar to adults but tend to be more strongly

rufous Rufous () is a color that may be described as reddish-brown or brownish-red, as of rust or oxidised iron. The first recorded use of ''rufous'' as a color name in English was in 1782. However, the color is also recorded earlier in 1527 as a dia ...

in colour with less contrast in patterns (Marchant and Higgins 1993; Ferguson-Lees and Christie 2001; Olsen and Fuentes 2004; Debus 1998).

Distribution and abundance

Although the little eagle has a large range and can be found in most parts of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, except heavily forested parts of the Great Dividing Range (Marchant and Higgins, 1993). Like so many Australian natives, it faces a deteriorating population due to a loss of habitat and competition from other species. One of the biggest factors to the decline of the little eagle is the decline of rabbits due to the release of the calicivirus, the eagle relied heavily on the rabbit population due to the extinction and massive decline of native terrestrial

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 or ...

s of rabbit size or smaller such as large

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

bandicoot Bandicoots are a group of more than 20 species of small to medium-sized, terrestrial, largely nocturnal marsupial omnivores in the order Peramelemorphia. They are endemic to the Australia–New Guinea region, including the Bismarck Archipelago t ...

bettong Bettongs, species of the genus ''Bettongia'', are potoroine marsupials once common in Australia. They are important ecosystem engineers displaced during the colonisation of the continent, and are vulnerable to threatening factors such as altere ...

s, juvenile

banded hare-wallaby The banded hare-wallaby, mernine, or munning (''Lagostrophus fasciatus'') is a marsupial currently found on the Islands of Bernier and Dorre off western Australia. Reintroduced populations have recently been established on islands and fenced ma ...

and other wallabies (Sharp et al. 2002). In the first national bird atlas in 1977–81, the little eagle was reported in 65% of one degree grid cells across Australia, with mostly high reporting rates (more than 40% of surveys per grid) across

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

and

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

Breeding Breeding is sexual reproduction that produces offspring, usually animals or plants. It can only occur between a male and a female animal or plant. Breeding may refer to: * Animal husbandry, through selected specimens such as dogs, horses, and rab ...

was recorded in 11% of cells, with the highest rates in New South Wales (NSW) and Victoria (Blakers et al. 1984). During the second national bird atlas in 1998–2002, the little eagle was recorded in 59% of grid cells, at mostly low reporting rates (recorded in less than 20% of surveys per grid). Breeding was recorded in 5% of grid cells (Barrett et al. 2003, 2007). Overall, there has been a national decline in reporting rate of 14%. In NSW over the last 20 years (two little eagle generations) the decline in reporting rate has been 39%, and over the past 30 years has been 50%, with an accelerating trend since the 1990s (Bounds 2008). The decline in reporting rate over the past 20 years for the South Eastern Highlands bioregion has been greater than 20% (Barrett et al. 2003, 2007). This bioregion includes the ACT. The little eagle was once common in the ACT (Olsen and Fuentes 2004) but has undergone significant decline (greater than 70%) over the last 20 years. In the late 1980s there was an estimated 13 breeding pairs in the ACT. The

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

occurred mainly in the northern half of the ACT with the highest concentrations found in the Murrumbidgee and the Molonglo river corridors (Taylor and COG 1992). By 2005 the only breeding record in the ACT was of an unsuccessful nest near

Uriarra Uriarra Village is a community in the District of Coree, Australian Capital Territory established in 1928 at the foothills of the Australian Alps. A nearby area to the north of the border in New South Wales is also called Uriarra. The settlem ...

Crossing (Olsen and Fuentes 2005). A more intensive ACT survey in 2007 found three breeding pairs, which fledged a total of four young (Olsen et al. 2008). In 2008 four breeding pairs were recorded and four young were fledged (Olsen et al. 2009). In 2009, three breeding pairs were recorded with three young being fledged (Olsen et al. 2010). Typical habitat for the little eagle includes

or open forest. Higher abundance of the species is associated with hillsides where there is a mixture of wooded and open areas such as riparian woodlands, forest margins and wooded farmland. Little eagles usually avoid large areas of dense forest, preferring to hunt in open woodland, where the birds use trees for lookouts (Marchant and Higgins 1993; Ferguson-Lees and Christie 2001). In the ACT, little eagles inhabit frequent open woodland and

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...

areas (Olsen and Fuentes 2004).

Conservation status

Little Eagle (Hieraaetus morphnoides) - Flickr - Lip Kee (1)

The little eagle was declared as ‘Vulnerable’ 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 townships. ...

(ACT) “under Section 38 of the Nature Conservation Act 1980”. It was also listed as ‘Vulnerable’ in

(NSW) in Part 1 of Schedule 2 of “the NSW Threatened Species Conservation Act 1995” and Gazetted on 12 February 2012. The little eagle is listed on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

as of ''least concern''. Reasons for it being classified as 'least concern' are that the bird of prey has a huge range, spanning up to 20,000km2 and the population size is only decreasing at a rate of 10% per ten years or 3 generations, instead of the required 30%. The Red List amended the status of the little eagle from "Not Recognized" in 2006 to "Least Concern". Also, the NSW Scientific Committee has made the determination to list the little eagle as a ''Vulnerable species'' under the Vulnerable species listing. The reasons for this listing is the reduction of

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

quality or diversity and

genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is dis ...

Ecology and behaviour

Reproduction

Little eagles nest in open woodland (usually on hillsides) and along tree-lined watercourses, with the

nest A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materia ...

typically placed in a mature, living tree. The birds build a stick nest lined with leaves and may use different nests in successive years, including those of other birds such as

crow A crow is a bird of the genus ''Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifical ...

s. A pair of little eagles will only reproduce once a year and each pair will only produce one or two eggs per season, usually laid in late August to early September (Marchant and Higgins 1993). After an incubation period of about 37 days, one or two young are

fledge Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...

d after approximately eight weeks (Olsen and Fuentes 2004; Debus et al. 2007; Debus and Ley 2009). Maturity in terms of breeding takes two to three years, leaving a large

population Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...

of juvenile eagles, mature eagles constitute roughly less than three-quarters of the population (Ferguson-Lees and Christie, 2001). Little eagle nesting territories are defended against intruders and advertised by soaring, undulating flight display, conspicuous perching and/or calling (Marchant and Higgins 1993; Debus et al. 2007; Bounds 2008). Movement behaviour varies between individuals, and may be partly migratory (being an altitudinal migrant), dispersive or permanently resident (Marchant and Higgins 1993). They tend to slip away at the first sign of human intrusion (Ferguson-lee and Christie 2001).

Prey

Little eagles hunt live prey and occasionally take

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, c ...

. The eagles search for prey by soaring, up to altitude, or by using an elevated exposed perch. The species is an agile, fast hunter swooping to take prey on the ground in the open but also from trees and shrubs (Marchant and Higgins 1993; Olsen et al. 2006; Debus et al. 2007; Debus and Ley 2009). Recorded prey species (from feeding observations, nest remains and faecal pellets) show considerable variation indicating a broad

diet Diet may refer to: Food * Diet (nutrition), the sum of the food consumed by an organism or group * Dieting, the deliberate selection of food to control body weight or nutrient intake ** Diet food, foods that aid in creating a diet for weight loss ...

, which seems to be determined primarily by the availability of prey of a suitable size. The little eagle would originally feed on small

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 lightweigh ...

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 rhynchocephalians ( ...

s and supplement its diet with large

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s on occasion, however with the introduction of rabbits and

fox Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush''). Twelve sp ...

es the little eagle's diet changed. Rabbits became widely abundant very quickly after being introduced, competing for habitat with native mammals. The introduction of foxes can also be attributed to the decline of the little eagle's main source of prey. The rabbit however is an ideal source of prey also, and so the rabbit population became the little eagle's main diet until the release of the calicivirus which decreased the rabbit population from between 65 and 85% in arid and semi-arid areas (Sharp et al. 2002). Debus (1998) notes that their diet varies geographically; the diet in

Northern Australia The unofficial geographic term Northern Australia includes those parts of Queensland and Western Australia north of latitude 26° and all of the Northern Territory. Those local government areas of Western Australia and Queensland that lie p ...

has a high proportion of birds, in the arid zone is mostly

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s, and in

Southern Australia The term Southern Australia is generally considered to refer to the states and territories of Australia of New South Wales, Victoria, Tasmania, the Australian Capital Territory and South Australia. The part of Western Australia south of lati ...

has a high proportion of juvenile rabbits. In the ACT region its diet comprises mostly rabbits and to a lesser extent birds (especially rosellas, magpie-larks and starlings) (Olsen and Fuentes 2004; Olsen et al. 2006, 2010). There is some evidence of prey partitioning between little eagles and the sympatric, larger

wedge-tailed eagle The wedge-tailed eagle (''Aquila audax'') is the largest bird of prey in the continent of Australia. It is also found in southern New Guinea to the north and is distributed as far south as the state of Tasmania. Adults of this species have lon ...

(''Aquila audax''), with the latter tending to take larger prey and to eat more carrion (Baker-Gabb 1984; Debus and Rose 1999; Olsen et al. 2006, 2010). However, rabbits are the most common dietary item for both eagle species near

Canberra Canberra ( ) is the capital city of Australia. Founded following the federation of the colonies of Australia as the seat of government for the new nation, it is Australia's largest inland city and the eighth-largest city overall. The ci ...

(Olsen et al. 2010), indicating potential for competition for prey. Both species also eat carrion and it is possible that the more numerous wedge-tailed eagles in the

(ACT) region keep little eagles away from macropod carcasses, and that little eagles would eat more carrion if not excluded by wedge-tailed eagles (Olsen et al. 2010).

Threats

The main threats to the species are the

destruction Destruction may refer to: Concepts * Destruktion, a term from the philosophy of Martin Heidegger * Destructive narcissism, a pathological form of narcissism * Self-destructive behaviour, a widely used phrase that ''conceptualises'' certain kind ...

and degradation of its foraging and breeding habitat causing it to come into competition with the larger and more dominant wedge-tailed eagle, ''Aquila audax'', (Olsen and Fuentes, 2005). The wedge-tailed eagle is not necessarily a predator of the little eagle but the two species share common habitat and prey and the large size and dominant nature of the wedge-tailed eagle could mean that the little eagle would be forced out of hunting and breeding grounds or even killed and eaten.

References

* Baker-Gabb DJ (1984). ''The breeding ecology of twelve species of diurnal raptor in north-western Victoria'', Australian Wildlife Research 11: 145–160. * Baker-Gabb DJ (1984). ''The breeding ecology of twelve species of diurnal raptor in north-western Victoria'', Australian Wildlife Research 11: 145–160. * Barrett G, Silcocks A, Barry S, Cunningham R and Poulter R (2003). ''The New Atlas of Australian Birds'' (Royal Australasian Ornithologists Union, Hawthorn East, Victoria). * Barrett GW, Silcocks AF, Cunningham R, Oliver DL, Weston MA and Baker J (2007). ''Comparison of atlas data to determine the conservation status of bird species in New South Wales, with emphasis on woodland-dependent species'', Australian Zoology 34: 37–77. * Blakers M, Davies SJJF, Reilly PN (1984). ''The Atlas of Australian Birds'' (Melbourne University Press, Melbourne). * Bounds J (2008). ''Nomination of a vulnerable species to the ACT Flora and Fauna Committee: Little Eagle, Canberra Bird Notes'' 33: 84–95. * * Debus S (1998). ''The Birds of Prey of Australia: A Field Guide'' (Oxford University Press, Melbourne). * Debus SJS, Hatfield TS, Ley AJ and Rose AB (2007). ''Breeding Biology and Diet of the Little Eagle Hieraaetus morphnoides in the New England Region of New South Wales'', Australian Field Ornithology 24: 137–157. * Debus SJS and Ley AJ (2009). ''Aspects of the breeding cycle of the Little Eagle Hieraaetus morphnoides'', Australian Field Ornithology 26: 76–99. * Ferguson-Lees J and Christie DA (2001). ''Raptors of the World'' (Helm, London). * * Marchant S and Higgins PJ eds. (1993). ''Handbook of Australian, New Zealand and Antarctic Birds'', Vol. 2 (Oxford University Press, Melbourne). * Olsen J and Fuentes E (2004). ''Preliminary report on the effect of the development of the Molonglo Valley on the community of birds of prey''. Unpublished report to the ACT Government. Applied Ecology Research Group, University of Canberra. * Olsen J and Fuentes E (2005). ''Collapse in numbers of breeding Little Eagles in the Australian Capital Territory'', Canberra Bird Notes 30: 141–145. * Olsen J, Fuentes E, Rose AB and Frost S (2006). ''Food and hunting of eight breeding raptors near Canberra, 1990–1994'', Australian Field Ornithology 26: 77–95. * Olsen J and Osgood M (2006). ''Numbers of breeding Little Eagles in the Australian Capital Territory in 2006'', Canberra Bird Notes 31: 178–182. * Olsen J, Osgood M, Maconachie M and Dabb G (2008). ''Numbers of breeding Little Eagles Hieraaetus morphnoides in the Australian Capital Territory in 2007'', Canberra Bird Notes 33: 77–80. * Olsen J, Osgood M, Maconachie M, Dabb G and Butterfield M (2009). ''Numbers of breeding Little Eagles Hieraaetus morphnoides in the Australian Capital Territory in 2008'', Canberra Bird Notes 34: 81–85. * Olsen J, Judge D, Fuentes E, Rose AB and Debus SJS (2010). ''Diets of Wedge-tailed Eagles (Aquila audax) and Little Eagles (Hieraaetus morphnoides) beeding near Canberra'', Australia, Journal of Raptor Research 44: 50–61. * Olsen J, Osgood M, Maconachie M, Dabb G and Butterfield M (2010). ''Little Eagles, Whistling Kites and Swamp Harriers in the Australian Capital Territory 2009'', Canberra Bird Notes 35: 81–84. * Sargatal, J. (ed.), ''Handbook of the birds of the world'', pp. 52–205. Lynx Edicions, Barcelona, Spain * Sharp A, Gibson L, Norton M, Ryan B, Marks A, Semeraro L (2002). ''The breeding season diet of the Wedge-tailed Eagle'' (Aquila audax) in western New South Wales and the influence of Rabbit Calicivirus Disease. Wildlife Research 29, 175–184. * Taylor McC and Canberra Ornithologists Group (1992). ''Birds of the Australian Capital Territory'': An Atlas (Canberra Ornithologists Group and the National Capital Planning Authority, Canberra). * Thiollay, J.-M. (1994). ''Family Accipitridae (Hawks and Eagles)''. In: del Hoyo, J.; Elliott, A.; Sargatal, J. (ed.), Handbook of the birds of the world, pp. 52–205. Lynx Edicions, Barcelona, Spain.

External links

*Gostelow, Ebenezer Edward (1935). "The Australian little eagle
watercolour
63.5 x 46 cm. {{Taxonbar, from1=Q27074631, from2=Q782098

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 w ...

Birds of Australia Birds of prey of Oceania Diurnal raptors of Australia