The Australian raven (''Corvus coronoides'') is a

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...

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 ...

in the genus '' Corvus'' native to much of southern and northeastern Australia. Measuring in length, it has all-black plumage, beak and mouth, as well as strong grey-black legs and feet. The upperparts are glossy, with a purple, blue, or green sheen, and its black feathers have grey bases. The Australian raven is distinguished from the Australian crow species by its throat hackles, which are prominent in adult birds. Older adult individuals have white irises, younger adults have white irises with an inner blue rim, while younger birds have dark brown irises until fifteen months of age, and hazel irises with an inner blue rim around each

pupil The pupil is a black hole located in the center of the Iris (anatomy), iris of the Human eye, eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing ...

until age two years and ten months.

Nicholas Aylward Vigors Nicholas Aylward Vigors (1785 – 26 October 1840) was an Irish zoologist and politician. He popularized the classification of birds on the basis of the quinarian system. Early life Vigors was born at Old Leighlin, County Carlow on 1785 a ...

and

Thomas Horsfield Thomas Horsfield (May 12, 1773 – July 24, 1859) was an American physician and naturalist who worked extensively in Indonesia, describing numerous species of plants and animals from the region. He was later a curator of the East India Company ...

described the Australian raven in 1827, its species name (''coronoides'') highlighting its similarity with the

carrion crow The carrion crow (''Corvus corone'') is a passerine bird of the family Corvidae and the genus ''Corvus'' which is native to western Europe and the eastern Palearctic. Taxonomy and systematics The carrion crow was one of the many species or ...

(''C. corone''). Two

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

are recognized, which differ slightly in calls and are quite divergent genetically. The preferred habitat is open woodland and transitional zones. It has adapted well to urban environments and is a common city bird in

Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mounta ...

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 ...

Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...

and

Brisbane Brisbane ( ) is the capital and most populous city of the Australian state of Queensland, and the third-most populous city in Australia and Oceania, with a population of approximately 2.6 million. Brisbane lies at the centre of the South ...

. An

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

and opportunistic feeder, it eats a wide variety of plant and animal material, as well as

food waste Food loss and waste is food that is not eaten. The causes of food waste or loss are numerous and occur throughout the food system, during production, processing, distribution, retail and food service sales, and consumption. Overall, about o ...

from urban areas. In eastern Australia, its range is strongly correlated with the presence of

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 ...

, and it has been blamed for killing lambs. However, this is very rare, and the raven most often scavenges for afterbirth and

stillborn Stillbirth is typically defined as fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. A stillbirth can result in the feeling of guilt or grief in the mother. The ter ...

animals as well as newborn lamb faeces. The Australian raven is territorial, with pairs generally bonding for life. Breeding takes place between July and September, with almost no variation across its range. The nest is a bowl-shaped structure of sticks sited high in a tree, or occasionally in a man-made structure such as a windmill or other building.

Taxonomy and naming

The Australian raven was first described by

and

in 1827, when they reported

George Caley George Caley (10 June 1770 – 23 May 1829) was an English botanist and explorer, active in Australia for the majority of his career. Early life Caley was born in Craven, Yorkshire, England, the son of a horse-dealer. He was educated at the ...

's early notes on the species from the Sydney district. Its specific epithet ''coronoides'' "crow-shaped" is derived from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''corone''/κορόνη "crow" and ''eidos''/είδος "shape" or "form". The two naturalists regarded the Australian raven as very similar in appearance to the

(''C. corone'') of Europe, though they noted it was larger with a longer bill. They did not give it a common name. The location where the

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...

was collected is not recorded, but thought to be in the

Parramatta Parramatta () is a suburb and major Central business district, commercial centre in Greater Western Sydney, located in the state of New South Wales, Australia. It is located approximately west of the Sydney central business district on the ban ...

district.

Christian Ludwig Brehm Christian Ludwig Brehm (24 January 1787 – 23 June 1864) was a German pastor and ornithologist. He was the father of the zoologist Alfred Brehm. Life Brehm was born in Schönau near Gotha on 24 January 1787. He was educated at Univers ...

described ''Corvus affinis'' in 1845, later determined to be this species. In his 1865 '' Handbook to the Birds of Australia'',

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, ...

recognised only one species of corvid in Australia, ''Corvus australis'', which he called the white-eyed crow. He used

Johann Friedrich Gmelin , fields = , workplaces = University of GöttingenUniversity of Tübingen , alma_mater = University of Tübingen , doctoral_advisor = Philipp Friedrich Gmelin Ferdinand Christoph Oetinger , academic_advisors = , docto ...

's 1788 name, which predated Vigors and Horsfield's description. In 1877

Richard Bowdler Sharpe Richard Bowdler Sharpe (22 November 1847 – 25 December 1909) was an English zoologist and ornithologist who worked as curator of the bird collection at the British Museum of natural history. In the course of his career he published several mo ...

recognised two species, but recorded that the feather bases of the type specimen of ''C. coronoides'' were white. He named ''C. coronoides'' as the "crow" and ''C. australis'' (as ''Corone australis'') the "raven". Scottish naturalist

William Robert Ogilvie-Grant William Robert Ogilvie-Grant (25 March 1863 – 26 July 1924) was a Scottish ornithologist. Early life and education Grant born on 25 March 1863 as second son of Capt. Hon. George Henry Essex Ogilvie-Grant, of Easter Elchies, Craigellachie, Sco ...

corrected this in 1912 after re-examining the type specimen, clarifying the species as ''C. coronoides'' (raven, and incorporating little and forest ravens) and ''C. cecilae'' (

Torresian crow The Torresian crow (''Corvus orru''), also called the Australian crow or Papuan crow, is a passerine bird in the crow family native to the north and west of Australia and nearby islands in Indonesia and Papua New Guinea. The species has a bla ...

Gregory Mathews Gregory Macalister Mathews CBE FRSE FZS FLS (10 September 1876 – 27 March 1949) was an Australian-born amateur ornithologist who spent most of his later life in England. Life He was born in Biamble in New South Wales the son of Robert H. M ...

described the western subspecies ''perplexus'' in 1912, naming it the southwestern crow and noting that it was smaller than the nominate subspecies. He called ''C. coronoides coronoides'' the eastern crow, listing its range as New South Wales, and described what is now the Australian crow as another subspecies, ''C. coronoides cecilae'', calling it the north-western crow and recording its range as northwestern Australia. In the same work he listed the raven as ''Corvus marianae'', with a type specimen from Gosford and listing its range as New South Wales. He listed the

little raven The little raven (''Corvus mellori'') is a species of the family Corvidae that is native to southeastern Australia. An adult individual is about in length, with completely black plumage, beak, and legs; as with all Australian species of ''Corv ...

and forest raven as subspecies. Mathews had erected ''C. marianae'' in 1911 as the name after declaring ''Corvus australis'' Gould to be preoccupied; French-American ornithologist Charles Vaurie acted as

first reviser The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...

under Article 24 of the

International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...

(ICZN) Code and discarded ''C. australis'' as a junior homonym—in 1788, Gmelin had used the same binomial name to describe the black nunbird—to preserve the stability of the name. This has been followed by later authors. German ornithologist

Erwin Stresemann Erwin Friedrich Theodor Stresemann (22 November 1889, in Dresden – 20 November 1972, in East Berlin) was a German naturalist and ornithologist. Stresemann was an ornithologist of extensive breadth who compiled one of the first and most compreh ...

lumped all Australian corvids plus other species as far as India into a single species, ''C. coronoides'', as he believed there was intergradation between all characteristics such as iris colour, colour of feather bases and plumage. This was hotly disputed by Mathews. The official

RAOU The Royal Australasian Ornithologists Union (RAOU), now part of BirdLife Australia, was Australia's largest non-government, non-profit, bird conservation organisation. It was founded in 1901 to promote the study and conservation of the native b ...

checklist listed three species (Australian raven, Torresian crow and little crow), with the little raven recognised as a fourth species in 1967 and forest raven in 1970. Stresemann described ''C. difficilis'' in 1943 from a single specimen, now thought to have been an unusual Australian raven or an Australian raven/Torresian crow hybrid. "Australian raven" has been designated the official name by the

International Ornithologists' Union The International Ornithologists' Union, formerly known as the International Ornithological Committee, is a group of about 200 international ornithologists, and is responsible for the International Ornithological Congress and other international ...

(IOC). Alternative names sometimes seen include southern raven, southern crow and Kelly, the last thought to have alluded to

the Kelly Gang ''The Kelly Gang'' is an Australian feature-length film about the Australian bush ranger, Ned Kelly. The film was released in 1920, and is the second film to be based on the life of Ned Kelly, the first being ''The Story of the Kelly Gang'', re ...

, though did not appear until the 1920s. Southern crow was considered by the RAOU before Australian raven was adopted as the official name for the species in 1926. The term "crow" is colloquially applied to any or all species of Australian corvid. The Australian raven was called ''wugan'' by the local

Eora The Eora (''Yura'') are an Aboriginal Australian people of New South Wales. Eora is the name given by the earliest European settlers to a group of Aboriginal people belonging to the clans along the coastal area of what is now known as the Sy ...

and

Darug The Dharug or Darug people, formerly known as the Broken Bay tribe, are an Aboriginal Australian people, who share strong ties of kinship and, in pre-colonial times, lived as skilled hunters in family groups or clans, scattered throughout much ...

inhabitants of the

Sydney Basin The Sydney Basin is an interim Australian bioregion and is both a structural entity and a depositional area, now preserved on the east coast of New South Wales, Australia and with some of its eastern side now subsided beneath the Tasman Sea ...

Evolution and systematics

The Australian raven's closest relatives are the other two species of raven occurring in Australia: the

and forest raven. The Australian raven is also somewhat closely related to the Torresian and little crow, although not as closely related as it is to the other raven species. Initial single gene genetic analysis of the genus using mitochondrial DNA showed the three raven species to belong to one lineage and the two crows to another. The genetic separation between species is small and there was a suggestion the little raven may be nested within the Australian raven, though the authors conceded more genetic work was needed. Subsequent multigene analysis using

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 ...

by Jønsson and colleagues in 2012 showed the eastern and western subspecies of the Australian raven to form two clades, almost as genetically distinct as the forest and little raven are to each other. This led the authors to propose that the subspecies be recognised as separate species. Ian Rowley proposed that the common ancestor of the five species diverged into a tropical crow and temperate raven sometime after entering Australia from the north, which molecular evidence indicates occurred in the early

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 The raven diverged into the ancestor of the forest and little ravens in the east and Australian raven in the west, this split occurring around 2 million years ago in the early

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

. As the climate became cooler and drier, the aridity of central Australia split them entirely. Furthermore, the eastern birds diverged into nomadic little ravens and, in forested refuges, forest ravens. As the climate eventually became warmer, the western birds spread eastwards and almost outcompeted forest ravens on mainland Australia. Rowley noted that the western subspecies of the Australian raven had features intermediate between the eastern subspecies of Australian and little ravens. Australianraven

Two subspecies are recognised: * ''C. c. coronoides'', the nominate or eastern subspecies, is found across most of eastern Australia. Its range is also highly correlated with the presence of sheep. This is thought to be because of the frequency of dead animals, which can be an important source of food. Ornithologist Ian Rowley held that the eastern subspecies was expanding eastwards before European colonisation, and that this suggested it was of younger origin than the western subspecies, which appears static. The advent of agriculture facilitated further spread. * ''C. c. perplexus'', the western subspecies, occurs from the head of the

Great Australian Bight The Great Australian Bight is a large oceanic bight, or open bay, off the central and western portions of the southern coastline of mainland Australia. Extent Two definitions of the extent are in use – one used by the International Hydrog ...

in South Australia westwards into Western Australia where its northern limits are

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 ...

and the mulga-eucalypt boundary line. It is less specialised in its habitat, as it does not share its distribution with the little raven, and does not appear to correlate with the range of sheep. The western subspecies has a slightly lower-pitched call than that of the eastern subspecies, with similarities to calls of the little raven. Of smaller size overall, it has a more slender bill and shorter hackles. There is otherwise no difference in plumage. Intermediate birds are found in the

Eyre Peninsula The Eyre Peninsula is a triangular peninsula in South Australia. It is bounded by the Spencer Gulf on the east, the Great Australian Bight on the west, and the Gawler Ranges to the north. Originally called Eyre’s Peninsula, it was named af ...

Gawler Ranges The Gawler Ranges are a range of stoney hills in South Australia to the north of Eyre Peninsula. The Eyre Highway skirts the south of the ranges. The Gawler Ranges National Park is in the ranges north of Kimba and Wudinna. The ranges are cover ...

and vicinity of

Lake Eyre Lake Eyre ( ), officially known as Kati Thanda–Lake Eyre, is an endorheic lake in east-central Far North South Australia, some north of Adelaide. The shallow lake is the depocentre of the vast endorheic Lake Eyre basin, and contains ...

in South Australia.

Description

Corvus coronoides - Glebe Point, Sydney, New South Wales, Australia -head-8

Measuring in length with a wingspan and weighing around the , the Australian raven is Australia's largest species of corvid. The adult Australian raven is an all black-bird with a black beak, mouth and tongue and sturdy black or grey-black legs and feet. The

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it conn ...

is fully feathered and the tarsus is long, and the feet large and strong. It has white irises. The plumage is glossy with a blue-purple to a blue-green sheen, greenish over the ear coverts, depending on the light. The underparts are not glossy. The Australian raven has throat feathers (hackles) that are

lanceolate The following is a list of terms which are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflet (bo ...

with rounded tips, while the other four species of Australian corvids have bifurcate tips, though this can be difficult to see in the field. The hackles are also longer than those of the other four species; when they are raised (such as when the bird is calling), they give the bird an unusual bearded appearance. The upper third of the upper mandible, including the nares and nasal groove, is covered with bristles, which can be up to long. The heavy-set beak is tipped with a slight hook, and is longer than the bird's head. The wings are long and broad, with the longest of its ten

primary feathers 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 ...

(usually the seventh but occasionally the eighth) almost reaching the end of the tail when the bird is at rest. The tail is rounded or wedge-shaped. The Australian raven can be distinguished from the two species of crow occurring in Australia by the grey base of the feathers, which is white in the latter species. The demarcation between pale and black regions on the feather is gradual in the ravens and sharply delineated in the crows. Feather bases are not normally visible when observing birds in the field, but can sometimes be seen on a windy day if the feathers are ruffled. Unlike the other four species, the Australian raven has a bare patch of skin under and extending to beside, the bill. This can be hard to discern in the field. The three species of raven are more heavily set with a broader chest than the two crow species, with the forest raven the stockiest of all. Relative size of species is only useful when two species can be seen side by side, as the overlap in size is large and the difference in size small. Juveniles resemble adults, but lack throat hackles, and sometimes have a pink fleshy

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 ...

. The bill is shorter and shallower; its base can be pinkish and the tip can be light grey. The plumage is more ruffled and softer in appearance, lacks the glossy highlights and often having a brown tinge. The bare skin on the throat is pink in birds that have recently left the nest. Eye colour varies with age, gradually lightening from juvenile to adult. Nestlings up to four months old have blue-grey irises, juveniles aged from four to fifteen months have dark brown irises, and immature birds have hazel irises with an inner blue rim around each pupil until age two years and ten months. Immature birds older than one year develop hackles, while some pink remains in the gape until the bird is two or three years of age.

Vocalisations

The territorial call of the Australian raven is a slow, high ''ah-ah-aaaah'' (similar to the

near-open front unrounded vowel The near-open front unrounded vowel, or near-low front unrounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , a lowercase of the ligature. Bo ...

(IPA:/ æ/)) with the last note drawn out. It uses this call to communicate with other Australian ravens in the area. When giving this call, the species has a horizontal posture, holding its head forward and body parallel to the ground, while perched on a prominent position. It ruffles its hackles and lowers its tail, and sometimes holds its beak open between calls. In contrast, the little raven and forest raven hold their bodies in an upright posture. This call becomes louder if trespassers encroach upon the Australian raven's territory. The five Australian species are very difficult to tell apart, with the call being the easiest way to do so, although the drawing-out of the final note—long held to be solely recorded for the Australian raven—has been recorded for the other species and is hence not diagnostic. The volume, pitch, tempo and order of notes can be changed depending on the message the Australian raven intends to convey. There is a variety of contact calls: a pair often makes a low murmuring sound when preening each other while roosting, and members of a flock carry on with a quiet chattering while at rest. Birds make a call and answer sequence if temporarily out of sight of one another while foraging. Birds in flocks make a single high-pitched ''caa'' while flying over another territory as a transit call to signify they are just passing through. An Australian raven will give a longer ''caa'' with a downward inflection to signify its return to the nest to its mate.

Distribution and habitat

The Australian raven is common throughout eastern Australia, and southern

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 ...

(the populations being connected by a narrow strip across 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 ...

), but it is rarer and more scattered in the north, with isolated sightings in Cape York at Coen, Windmill Creek and the Mitchell River, and becoming more common south of

Rockhampton Rockhampton is a city in the Rockhampton Region of Central Queensland, Australia. The population of Rockhampton in June 2021 was 79,967, Estimated resident population, 30 June 2018. making it the fourth-largest city in the state outside of t ...

in central Queensland. It is found throughout New South Wales, though is uncommon in the northeast of the state. It is rare in the

Australian Alps The Australian Alps is a mountain range in southeast Australia. It comprises an interim Australian bioregion,0042-5184 However, the moth has also been a biovector of arsenic, transporting it from lowland feeding sites over long distances int ...

, being replaced there by the little raven. It occurs across Victoria and eastern South Australia, through the

and

into Western Australia, across the state north to the Wooramel River. It is found on some offshore islands such as

Rottnest Island Rottnest Island ( nys, Wadjemup), often colloquially referred to as "Rotto", is a island off the coast of Western Australia, located west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, Rottnest is an A-cla ...

and

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 ...

. It is a rare vagrant to

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland Po ...

, though it was recorded as a vagrant in

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 coun ...

in the 1870s, this has not been confirmed. The Australian raven can be found in a wide range of natural and modified habitats. It requires available water and trees (or buildings) to roost in or perch on. Preferred habitats include

eucalypt Eucalypt is a descriptive name for woody plants with capsule fruiting bodies belonging to seven closely related genera (of the tribe Eucalypteae) found across Australasia: ''Eucalyptus'', ''Corymbia'', ''Angophora'', '' Stockwellia'', ''Allosyn ...

-dominated

sclerophyll Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...

forest, and farmland adjacent to trees. It is also found in heath and mangroves. In areas where it occurs with the little raven, namely over much of central New South Wales, Victoria and into South Australia, the Australian raven is restricted to more forested areas while the latter species prefers more open areas. Similarly, in inland Australia it can share a range with the little crow, as the two do not appear to compete. However, the ranges of similar-sized forest raven and Torresian crow only narrowly overlap with the Australian raven as all three compete with each other. In central and western regions, Australian ravens and Torresian crows vie for the scattered uncommon trees and outcrops, and only one or the other are found there. It co-occurs with the forest raven in northeastern New South Wales from Port Stephens northwards. The Australian raven has adapted very well to human habitation in some cities and is the most common corvid in

and

; in

Melbourne Melbourne ( ; Boonwurrung/ Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a metro ...

and

Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...

it is replaced by the little raven, and by the Torresian crow in

. Its large range, abundance and increasing population mean it is classified as ''Least Concern'' 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 biolo ...

Behaviour

Difficulties in distinguishing Australian corvids has hampered understanding of seasonal movements. The Australian raven is thought to be largely sedentary, with most movement of over due to flocks of non-breeding subadult birds. Juvenile birds leave their parents and join flocks when they are four or five months old. Smaller flocks of 8–30 birds stay within an area of around 260 square kilometres, while larger flocks of up to 300 birds may travel hundreds of kilometres seeking food. A single breeding pair and their brood can occupy a territory of up to around and remains there year-round, though groups of ravens may enter this area to forage. Australian ravens will defend their territory by chasing, dive-bombing and occasionally striking the backs of birds of prey, foxes or even people. They generally mate for life, though occasionally one male has been found to be mated with two females in adjacent territories. If the female dies, the male Australian raven maintains the territory and finds another mate, while if the male bird is lost, the female abandons the territory. No courtship behaviour has been observed, and species that mate for life often lack elaborate courting displays. Once they begin breeding at three years of age, they live another four to five years on average. During this time they produce two surviving young each year on average. The longest-lived Australian raven recorded is an adult (of at least 3 years of age) that was banded and recaptured alive 12 years and 5 months later. Australian ravens generally walk when moving around on the ground, though do hop when hurrying. They preen themselves frequently, particularly when roosting in the middle of the day. They also engage in allopreening, where birds will preen each other's head and neck. This takes place particularly in autumn, winter and spring, and is important in pair bonding. Either member may initiate it, generally by landing near the other bird, shuffling next to its mate, then bending its head forward and presenting its nape.

Breeding

Australian ravens begin breeding once they are three years old. Breeding season is from July to September, with no substantial difference in timing across its range around the country despite it inhabiting a range of diverse climates and habitats across 19 degrees of latitude. Rowley has pointed out this is unusual for a bird species with a wide range and has postulated that breeding is initiated by day length. Rarely, breeding can take place in May, June or October. Australian ravens generally nest in tall trees, never near to the ground as some species do. The nest also functions as a lookout post and so tall or emergent trees are selected. The ravens occasionally nest on buildings, telegraph poles, or tall windmills which allow the species to occupy areas lacking in tall trees. Windmills may have assisted the spread of the species in North Queensland and the Northern Territory. The highest recorded corvid nest in Australia was found atop the AWA Tower in Sydney. Nests are generally large and untidy, consisting of a bowl or platform of sticks lined with grasses, barks, and feathers that can be up to thick. As they are relatively heavy, they are built on larger forks in trees rather than out in the canopy. Building the nest is often time-consuming initially as the birds try (and often fail) to wedge sticks, which are long and thick, into the tree fork to make a platform. Thinner sticks and rootlets are used to make the bowl before the bowl is lined with feathers. Both birds build the nest, with the female taking over the lining of the nest while the male brings her material. New nests are built each year generally, as the re-use of old ones might spread disease or parasites—nests become caked with faeces as the nestlings grow and the parents cannot keep up with its removal. Furthermore, old nests often disintegrate within twelve months due to their exposed locations. The female develops a

brood patch A brood patch is a patch of featherless skin on the underside of birds during the nesting season. Feathers act as inherent insulators, and prevent efficient incubation. Birds have solved this evolutionary dilemma by developing dedicated brood pat ...

—a patch of bare skin on the bird's underparts that reddens and becomes much more extensive from around three weeks before the first egg is laid. The skin itself is oedematous and wrinkled, and does not get re-feathered until December after the breeding season has finished. Their lofty locations makes monitoring of Australian raven nests difficult. A clutch can comprise up to six eggs, though usually four or five are laid, with five being the most common number. Measuring , eggs are pale green or bluish-green and splotched with darker olive, brown and blackish markings. Eggs are quite variable, and thus which Australian corvid laid them cannot be reliably identified. Incubation of the eggs is done solely by the female over roughly 20 days. Incubation is intermittent initially, becoming constant by the time the third or fourth egg is laid. Only one brood is raised per year, though a second clutch may be laid if the first clutch is lost early in the season. Late clutches have poor survival rates, possibly due to chicks getting dehydrated on hot days as the year progresses or being eaten by wedge-tailed eagles. The chicks are

altricial In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...

and nidicolous; that is, they are born helpless, naked and blind, and remain in the nest for an extended period. They have pink skin until 5 days of age, when feathers under the skin turn it grey. They lose their

egg tooth An egg tooth is a temporary, sharp projection present on the bill or snout of an oviparous animal at hatching. It allows the hatchling to penetrate the eggshell from inside and break free. Birds, reptiles, and monotremes possess egg teeth as ha ...

at the same time. Their eyes begin opening at 5 to 6 days of age and are fully open by 11 to 12 days, by which time their feathers begin emerging. At 14 days, their primary feathers begin emerging, and they are fully feathered by 35–36 days old. They leave the nest at 40–45 days of age, and stay with the parents for three to four months after that. They follow their parents and beg for food for the first month outside the nest but are feeding themselves by the third month. Young birds are often attacked when they enter neighbouring territories, and melees ensue as their parents try to defend them and herd them back.

Feeding

Wedge-tailed eagle and Australian raven Diamantina Developmental Road Boulia Shire Central Western Queensland P1080979

The Australian raven is omnivorous, though eats more meat than smaller corvids. Its diet in summer contains a high proportion of insects, while more plant items are eaten in autumn. Flesh makes up over half its diet in winter. Invertebrates commonly eaten include

spider Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

millipede Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derived from this feature. Each double-legged segment is a resu ...

centipede Centipedes (from New Latin , "hundred", and Latin , " foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, ...

s (which ravens behead before eating),

grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grasshopp ...

cicada The cicadas () are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into tw ...

s and

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sy ...

s (especially of the family

Noctuidae The Noctuidae, commonly known as owlet moths, cutworms or armyworms, are a family of moths. They are considered the most controversial family in the superfamily Noctuoidea because many of the clades are constantly changing, along with the other ...

), which are important in feeding nestlings. Australian ravens sometimes eat yabbies (''Cherax destructor'') from the edges of dams. Unusually for a ground-feeding omnivore,

earthworm An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. T ...

s are rarely eaten. Australian ravens have been reported killing birds of such size as young

galah The galah (; ''Eolophus roseicapilla''), also known as the pink and grey cockatoo or rose-breasted cockatoo, is the only species within genus ''Eolophus'' of the cockatoo family. Found throughout Australia, it is among the most common of the ...

s (''Eolophus roseicapillus'') and

starlings Starlings are small to medium-sized passerine birds in the family Sturnidae. The Sturnidae are named for the genus '' Sturnus'', which in turn comes from the Latin word for starling, ''sturnus''. Many Asian species, particularly the larger ones, ...

(''Sturnus vulgaris''). Most mammals are eaten as carrion, as many species are too large for the raven to kill, though young rabbits are a frequent prey item. Australian ravens drink water frequently, up to ten times a day in hot weather. Birds have been observed dunking pieces of meat in water before eating them, as well as doing the same with hard biscuits to make them soggy and soft. Australian ravens are intelligent birds, and like many other corvids have innovative methods of seeking out food. Foraging takes place in the early morning or late afternoon; birds rest in the hotter part of the day. Food is taken mainly from the ground, birds either finding objects while flying overhead or by walking along and looking. However, they occasionally feed in trees—Australian ravens forage eucalypt foliage for Christmas beetles (''Anoplognathus''), and devote a substantial amount of time to look for nests and eggs to eat. They have also been known to take golf balls from fairways, possibly mistaking them for eggs. Ravens use their bill rather than their feet to explore or turn items on the ground (rocks or sticks) over or hold or snatch food while flying. They have also been recorded using fence posts as anvils to bash snails against before eating them. Australian ravens most often eat food where they find it unless taking food back for nestlings. Occasionally they have been observed caching carrion or a killed animal in a hole nearby to store it. They can pack shredded meat in their mouth under their tongue. Australian ravens have adapted well to eating food scraps in urban areas, such as school playgrounds, rubbish tips, bins outside supermarkets or restaurants, abattoirs, piggeries and farmyards. In one isolated study, they were observed feeding on nectar from eucalypt flowers. Australian ravens sometimes forage in mixed-species flocks with any of the other four species of Australian corvids. Sometimes they are aggressive with little ravens if both are at a food source and drive them off, though not if the smaller species greatly outnumber the larger.

Parasites and predators

circovirus ''Circovirus'' is a genus of viruses, in the family '' Circoviridae''. Birds (such as pigeons and ducks) and pigs serve as natural hosts, though dogs have been shown to be infected as well. It is a single stranded DNA virus (ssDNA). There are 49 ...

—given the name raven circovirus or RaCV—was isolated from an Australian raven suffering from feather lesions in 2006. It has affinities with canary circovirus (CaCV) and pigeon circovirus (PiCV). Its clinical significance is unknown. A species of ''

Isospora ''Isospora'' is a genus of internal parasites in the subclass Coccidia. It is responsible for the condition isosporiasis, which causes acute, non-bloody diarrhoea in immunocompromised individuals. Taxonomy At least 248 species were originall ...

''—given the name of ''I. coronoideae'' was isolated from this species, its only known host. Tick infestation is rare in the Australian raven, with '' Ixodes holocyclus'' and ''

Amblyomma triguttatum ''Amblyomma triguttatum'', commonly known as the kangaroo tick, is a species of tick in the genus ''Amblyomma'' native to Australia. There are four subspecies, one or more of which might be separate species. The nominate subspecies is a vector f ...

'' recorded. Lice and hippoboscid flies have been recorded yet little-researched, and an infestation by the fly '' Passeromyia longicornis'' was recorded in one nest. The

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 lo ...

(''Aquila audax'') preys on adult, nestling, and fledgling Australian ravens, while the little eagle (''Hieraaetus morphnoides'') also takes nestlings, and

powerful owl The powerful owl (''Ninox strenua''), a species of owl native to south-eastern and eastern Australia, is the largest owl on the continent. It is found in coastal areas and in the Great Dividing Range, rarely more than inland. The IUCNRed List ...

(''Ninox strenua'') has been recorded killing adults; other birds of prey are seen as threats, yet there is no evidence they have successfully preyed on the ravens. The introduced

red fox The red fox (''Vulpes vulpes'') is the largest of the true foxes and one of the most widely distributed members of the Order (biology), order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe ...

(''Vulpes vulpes'') competes with the Australian raven for carrion and can drive it off. It may also kill young birds that it catches on the ground. The

channel-billed cuckoo The channel-billed cuckoo (''Scythrops novaehollandiae'') is a species of cuckoo in the family Cuculidae. It is monotypic within the genus ''Scythrops''.Payne (2005), p. 380. The species is the largest brood parasite in the world, and the largest ...

(''Scythrops novaehollandiae'') has been recorded as a

brood parasite Brood parasites are animals that rely on others to raise their young. The strategy appears among birds, insects and fish. The brood parasite manipulates a host, either of the same or of another species, to raise its young as if it were it ...

Relationship with humans

Australian ravens sometimes die by being shot or poisoned—generally by farmers. Despite their fondness for roadkill, fewer ravens are hit by vehicles than

Australian magpie The Australian magpie (''Gymnorhina tibicen'') is a black and white passerine bird native to Australia and southern New Guinea. Although once considered to be three separate species, it is now considered to be one, with nine recognised su ...

s. Research in the 1950s and 60s showed that 64% of Australian ravens perished in their first year of life. Immature birds are most at risk of dying. The Australian raven is a peaceful bird, showing no aggression toward humans or other birds without reason. However, the Australian raven is frequently blamed for the loss of young lambs. Scientific observation in the country's southeast showed that the killing of healthy lambs was rare, but that sick animals were predisposed to being attacked. Australian ravens mostly eat faeces (often from the lamb's anus), afterbirth or stillborn lambs. Newborn lamb faeces is nutritious, containing around 21–44% protein, 9–37% fat and 10–30% carbohydrate. It has the consistency of

treacle Treacle () is any uncrystallised syrup made during the refining of sugar.Oxford Dictionary The most common forms of treacle are golden syrup, a pale variety, and a darker variety known as black treacle, similar to molasses. Black treacle has ...

and often sticks to the lamb's hindquarters or tail. The raven bites a sleeping lamb's tail, holding on and walking behind it when it wakes up. A healthy lamb would respond by running away or butting the bird, but a sick one might not respond and be attacked further as it alerts the bird that it is vulnerable. Wounded lambs can also succumb to ''

Clostridium ''Clostridium'' is a genus of anaerobic, Gram-positive bacteria. Species of ''Clostridium'' inhabit soils and the intestinal tract of animals, including humans. This genus includes several significant human pathogens, including the causative a ...

'' infection as these bacteria are present on raven bills. Ravens bring some benefits to agricultural areas as they clean away carrion and eat insects that are potentially damaging to crops. In areas of Western Australia, the species is classified as a Declared Pest of Agriculture under the provisions of the ''Agriculture and Related Resources Protection Act 1976'', meaning that shooting on private land in rural areas is legal, although should be considered only after other options have been exhausted.

In Indigenous culture

In Australian Aboriginal

mythology Myth is a folklore genre consisting of narratives that play a fundamental role in a society, such as foundational tales or origin myths. Since "myth" is widely used to imply that a story is not objectively true, the identification of a narra ...

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 scientifica ...

is a

trickster In mythology and the study of folklore and religion, a trickster is a character in a story ( god, goddess, spirit, human or anthropomorphisation) who exhibits a great degree of intellect or secret knowledge and uses it to play tricks or otherwi ...

culture hero A culture hero is a mythological hero specific to some group ( cultural, ethnic, religious, etc.) who changes the world through invention or discovery. Although many culture heroes help with the creation of the world, most culture heroes are impo ...

and ancestral being. In the

Kulin nation The Kulin nation is an alliance of five Aboriginal nations in south central Victoria, Australia. Their collective territory extends around Port Phillip and Western Port, up into the Great Dividing Range and the Loddon and Goulburn River va ...

in central

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 ...

he was known as ''Waa'' (also ''Wahn'' or ''Waang'') and was regarded as one of two moiety ancestors, the other being the more sombre eaglehawk ''

Bunjil Bunjil, also spelt Bundjil, is a creator deity, culture hero and ancestral being, often depicted as a wedge-tailed eagle in Australian Aboriginal mythology of some of the Aboriginal peoples of Victoria. Creation stories In the Kulin nation ...

''. Legends relating to Crow have been observed in various Aboriginal language groups and cultures across Australia. To the

Noongar The Noongar (, also spelt Noongah, Nyungar , Nyoongar, Nyoongah, Nyungah, Nyugah, and Yunga ) are Aboriginal Australian peoples who live in the South West, Western Australia, south-west corner of Western Australia, from Geraldton, Western Au ...

people of southwestern Australia, the Australian raven was ''Waardar'', "the Watcher" and was wily and unpredictable. Noongar people were socially divided into two moieties or kinships: ''waardarng-maat'' and ''marrnetj-maat'', or members of the Australian raven and

long-billed corella The long-billed corella or slender-billed corella (''Cacatua tenuirostris'') is a cockatoo native to Australia, which is similar in appearance to the little corella. This species is mostly white, with a reddish-pink face and forehead, and has a lo ...

(''Cacatua tenuirostris'') respectively.

Explanatory notes

References

Citations

Cited texts

External links

An Australian Raven call (two birds)
* {{Taxonbar, from=Q1584072 Corvus Ravens Endemic birds of Australia Birds described in 1827 Articles containing video clips Taxa named by Nicholas Aylward Vigors