fbpx
Wikipedia

Australian raven

The Australian raven (Corvus coronoides) is a passerine bird in the genus Corvus native to much of southern and northeastern Australia. Measuring 46–53 centimetres (18–21 in) in length, it has all-black plumage, beak and mouth, as well as strong grey-black legs and feet. The upperparts are glossy, with a purple, blue, or green sheen, and its black feathers have grey bases. The Australian raven is distinguished from the Australian crow species by its throat hackles, which are prominent in adult birds. Older adult individuals have white irises, younger adults have white irises with an inner blue rim, while younger birds have dark brown irises until fifteen months of age, and hazel irises with an inner blue rim around each pupil until age two years and ten months. Nicholas Aylward Vigors and Thomas Horsfield described the Australian raven in 1827, its species name (coronoides) highlighting its similarity with the carrion crow (C. corone). Two subspecies are recognized, which differ slightly in calls and are quite divergent genetically.

Australian raven
Near Kurnell, New South Wales
An audio recording of an Australian raven.
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Corvidae
Genus: Corvus
Species:
C. coronoides
Binomial name
Corvus coronoides
Subspecies
C. c. coronoides
C. c. perplexus
Synonyms

Corvus affinis Brehm, 1845
Corvus marianae Mathews, 1911
Corvus difficilis Stresemann, 1943
Corvus australis Gmelin, 1788
Corone australis (Gmelin)

The preferred habitat is open woodland and transitional zones. It has adapted well to urban environments and is a common city bird in Sydney, Canberra, Perth and Brisbane. An omnivorous and opportunistic feeder, it eats a wide variety of plant and animal material, as well as food waste from urban areas. In eastern Australia, its range is strongly correlated with the presence of sheep, and it has been blamed for killing lambs. However, this is very rare, and the raven most often scavenges for afterbirth and stillborn 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 edit

The Australian raven was first described by Nicholas Aylward Vigors and Thomas Horsfield in 1827, when they reported George Caley's early notes on the species from the Sydney district.[2] Its specific epithet coronoides "crow-shaped" is derived from the Greek corone/κορόνη "crow" and eidos/είδος "shape" or "form".[3] The two naturalists regarded the Australian raven as very similar in appearance to the carrion crow (C. corone) of Europe,[4] though they noted it was larger with a longer bill. They did not give it a common name.[2] The location where the type specimen was collected is not recorded, but thought to be in the Parramatta district.[5] Christian Ludwig Brehm described Corvus affinis in 1845,[6] later determined to be this species.[7] In his 1865 Handbook to the Birds of Australia, John Gould recognised only one species of corvid in Australia, Corvus australis, which he called the white-eyed crow. He used Johann Friedrich Gmelin's 1788 name,[a] which predated Vigors and Horsfield's description.[10] In 1877 Richard Bowdler Sharpe 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".[5] Scottish naturalist William Robert Ogilvie-Grant 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).[11]

Gregory Mathews 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 and forest raven as subspecies.[12] Mathews had erected C. marianae in 1911 as the name after declaring Corvus australis Gould to be preoccupied;[13] French-American ornithologist Charles Vaurie acted as first reviser under Article 24 of the International Code of Zoological Nomenclature (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.[14] This has been followed by later authors.[15]

German ornithologist Erwin Stresemann 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 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.[5]

"Australian raven" has been designated the official name by the International Ornithologists' Union (IOC).[16] Alternative names sometimes seen include southern raven, southern crow and Kelly,[4] the last thought to have alluded to the Kelly Gang, 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.[17] The term "crow" is colloquially applied to any or all species of Australian corvid.[5] The Australian raven was called wugan by the local Eora and Darug inhabitants of the Sydney Basin.[18]

Evolution and systematics edit

Evolution of Australasian corvids
crow ancestor
raven ancestor

Australian raven (eastern subspecies)

Australian raven (western subspecies)

Phylogenetic tree based on Jønsson et al. 2012[19]

The Australian raven's closest relatives are the other two species of raven occurring in Australia: the little raven 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.[20] Subsequent multigene analysis using nuclear DNA 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.[19]

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,[21] which molecular evidence indicates occurred in the early Pliocene epoch around 4 million years ago.[19] The raven diverged into the ancestor of the forest and little ravens in the east and Australian raven in the west,[21] this split occurring around 2 million years ago in the early Pleistocene.[19] 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.[21]

 
Subspecies perplexus, Perth, WA, showing smaller hackles

Two subspecies are recognised:

  • C. c. coronoides, the nominate or eastern subspecies, is found across most of eastern Australia.[4] 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.[5]
  • C. c. perplexus, the western subspecies, occurs from the head of the Great Australian Bight in South Australia westwards into Western Australia where its northern limits are Shark Bay and the mulga-eucalypt boundary line.[4] 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.[5] The western subspecies has a slightly lower-pitched call than that of the eastern subspecies,[22] 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.[23] Intermediate birds are found in the Eyre Peninsula, Gawler Ranges and vicinity of Lake Eyre in South Australia.[4]

Description edit

 
Adult in Sydney. Shows bare skin on neck.

Measuring 46–53 cm (18–21 in) in length with a 100 cm (39 in) wingspan and weighing around the 650 g (1.43 lb), the Australian raven is Australia's largest species of corvid.[4] 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.[24] The tibia is fully feathered and the tarsus is long, and the feet large and strong.[25] It has white irises.[24] 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.[26] The Australian raven has throat feathers (hackles) that are lanceolate with rounded tips, while the other four species of Australian corvids have bifurcate tips, though this can be difficult to see in the field.[22] 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,[26] which can be up to 3 cm (1.2 in) long.[27] The heavy-set beak is tipped with a slight hook,[26] and is longer than the bird's head. The wings are long and broad, with the longest of its ten primary feathers (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.[25]

 
 
 
 
Changes in eye colour. Clockwise from upper left: Juvenile with dark irises, Hyde Park, Sydney. Immature with hazel irises, Centennial Park, Sydney. Adult with all-white irises, University of Sydney. Maturing bird with white irises with slight blue ring, Nowra.

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.[22] 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.[28] 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.[29]

Juveniles resemble adults, but lack throat hackles,[27] and sometimes have a pink fleshy gape.[30] The bill is shorter and shallower;[26] its base can be pinkish and the tip can be light grey.[24] The plumage is more ruffled and softer in appearance, lacks the glossy highlights and often having a brown tinge.[26] The bare skin on the throat is pink in birds that have recently left the nest.[24] Eye colour varies with age, gradually lightening from juvenile to adult.[26] 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.[5][b] Immature birds older than one year develop hackles,[25] while some pink remains in the gape until the bird is two or three years of age.[24]

Vocalisations edit

The territorial call of the Australian raven is a slow, high ah-ah-aaaah (similar to the near-open front unrounded vowel (IPA:/æ/)) with the last note drawn out. It uses this call to communicate with other Australian ravens in the area.[31] 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.[29] This call becomes louder if trespassers encroach upon the Australian raven's territory.[32] The five Australian species are very difficult to tell apart, with the call being the easiest way to do so,[4] 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.[29]

A raven (Corvus coronoides coronoides) produces an amusing variety of sounds.

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.[32]

Distribution and habitat edit

The Australian raven is common throughout eastern Australia,[30] and southern Western Australia (the populations being connected by a narrow strip across the Nullarbor Plain), but it is rarer and more scattered in the north, with isolated sightings in Cape York at Coen, Windmill Creek and the Mitchell River,[33] and becoming more common south of Rockhampton 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, being replaced there by the little raven. It occurs across Victoria and eastern South Australia, through the Eyre Peninsula and Nullarbor Plain into Western Australia, across the state north to the Wooramel River.[34] It is found on some offshore islands such as Rottnest Island[35] and Kangaroo Island.[34] It is a rare vagrant to Lord Howe Island.[34]

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-dominated sclerophyll 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,[22] the Australian raven is restricted to more forested areas while the latter species prefers more open areas.[36] 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.[5] It co-occurs with the forest raven in northeastern New South Wales from Port Stephens northwards.[22] The Australian raven has adapted very well to human habitation in some cities and is the most common corvid in Canberra, Sydney and Perth; in Melbourne and Adelaide it is replaced by the little raven,[22] and by the Torresian crow in Brisbane.[37] Its large range, abundance and increasing population mean it is classified as Least Concern on the IUCN Red List.[1]

Behaviour edit

Rush Creek, SE Queensland, Australia

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 16 km (9.9 mi) due to flocks of non-breeding subadult birds.[38] 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.[39]

A single breeding pair and their brood can occupy a territory of up to around 120 hectares (300 acres) and remains there year-round, though groups of ravens may enter this area to forage.[38] Australian ravens will defend their territory by chasing, dive-bombing and occasionally striking the backs of birds of prey, foxes or even people.[40] They generally mate for life, though occasionally one male has been found to be mated with two females in adjacent territories.[32] 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.[41] No courtship behaviour has been observed, and species that mate for life often lack elaborate courting displays.[32] 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.[41] 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.[39]

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.[32] 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.[42]

Breeding edit

Australian ravens begin breeding once they are three years old.[41] Breeding season is from July to September,[43] 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.[44] Australian ravens generally nest in tall trees, never near to the ground as some species do.[33] The nest also functions as a lookout post and so tall or emergent trees are selected.[45] The ravens occasionally nest on buildings, telegraph poles,[33] 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.[45]

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 5 cm (2.0 in) thick.[46] 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 30–60 cm (12–24 in) long and 0.6–1.2 cm (1412 in) 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.[45] The female develops a brood patch—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.[44]

Their lofty locations makes monitoring of Australian raven nests difficult.[45] A clutch can comprise up to six eggs, though usually four or five are laid, with five being the most common number.[45] Measuring 45 by 30 mm (1+34 by 1+14 in), eggs are pale green or bluish-green and splotched with darker olive, brown and blackish markings.[43] Eggs are quite variable, and thus which Australian corvid laid them cannot be reliably identified.[45] 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.[46] 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.[44] The chicks are altricial and nidicolous; that is, they are born helpless, naked and blind, and remain in the nest for an extended period.[46] They have pink skin until 5 days of age, when feathers under the skin turn it grey. They lose their egg tooth at the same time.[45] 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.[46] 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.[45]

Feeding edit

 
Australian raven scavenging roadkill with a wedge-tailed eagle

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 spiders, millipedes, centipedes (which ravens behead before eating), grasshoppers, cicadas and caterpillars (especially of the family Noctuidae), which are important in feeding nestlings. Australian ravens sometimes eat yabbies (Cherax destructor) from the edges of dams. Unusually for a ground-feeding omnivore, earthworms are rarely eaten. Australian ravens have been reported killing birds of such size as young galahs (Eolophus roseicapillus) and starlings (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.[47] 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,[32] as well as doing the same with hard biscuits to make them soggy and soft.[48]

Australian ravens are intelligent birds, and like many other corvids have innovative methods of seeking out food.[19] 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.[32] 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.[47] 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.[32] 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.[33] In one isolated study, they were observed feeding on nectar from eucalypt flowers.[49] 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.[50]

Parasites and predators edit

A circovirus—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.[51] A species of Isospora—given the name of I. coronoideae was isolated from this species, its only known host.[52] Tick infestation is rare in the Australian raven, with Ixodes holocyclus and Amblyomma triguttatum recorded. Lice and hippoboscid flies have been recorded yet little-researched, and an infestation by the fly Passeromyia longicornis was recorded in one nest.[45]

The wedge-tailed eagle (Aquila audax) preys on adult, nestling, and fledgling Australian ravens, while the little eagle (Hieraaetus morphnoides) also takes nestlings, and powerful owl (Ninox strenua) has been recorded killing adults;[27] other birds of prey are seen as threats, yet there is no evidence they have successfully preyed on the ravens. The introduced red fox (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.[45] The channel-billed cuckoo (Scythrops novaehollandiae) has been recorded as a brood parasite.[27]

Relationship with humans edit

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 magpies. 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.[39] 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.[53] 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.[54] Australian ravens mostly eat faeces (often from the lamb's anus), afterbirth or stillborn lambs.[48][c] Newborn lamb faeces is nutritious, containing around 21–44% protein, 9–37% fat and 10–30% carbohydrate. It has the consistency of treacle 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 infection as these bacteria are present on raven bills.[54] Ravens bring some benefits to agricultural areas as they clean away carrion and eat insects that are potentially damaging to crops.[55] 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.[56]

In Indigenous culture edit

In Australian Aboriginal mythology, Crow is a trickster, culture hero and ancestral being. In the Kulin nation in central Victoria 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. Legends relating to Crow have been observed in various Aboriginal language groups and cultures across Australia.[57]

To the Noongar 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 (Cacatua tenuirostris) respectively.[58]

Explanatory notes edit

  1. ^ John Latham had described the south-seas raven in 1781, with loose throat feathers and being found in "the Friendly Isles" in the South Seas, but did not give it a binomial name.[8] The place is thought to be Tonga.[5] Gmelin gave it the name Corvus australis in the 13th edition of Systema naturae in 1788.[9]
  2. ^ Rowley and colleagues recorded iris colour changes of all five Australian corvid species raised in captivity.[5]
  3. ^ Lambing takes place in late winter, with stillbirth rates around 20%, so there is a supply of carrion around farming areas.[48]

References edit

Citations edit

  1. ^ a b BirdLife International (2016). "Corvus coronoides". IUCN Red List of Threatened Species. 2016: e.T22706033A94047450. doi:10.2305/IUCN.UK.2016-3.RLTS.T22706033A94047450.en. Retrieved 12 November 2021.
  2. ^ a b Vigors, Nicholas Aylward; Horsfield, Thomas (1827). "A Description of the Australian Birds in the Collection of the Linnean Society; with an Attempt at Arranging them According to their Natural Affinities". Transactions of the Linnean Society of London. 15: 170–331 [261]. doi:10.1111/j.1095-8339.1826.tb00115.x.
  3. ^ Liddell, Henry George; Scott, Robert (1980). A Greek-English Lexicon (Abridged ed.). Oxford: Oxford University Press. ISBN 978-0-19-910207-5.
  4. ^ a b c d e f g Higgins 2006, p. 690.
  5. ^ a b c d e f g h i j Rowley, Ian (1970). "The Genus Corvus (Aves: Corvidae) in Australia". CSIRO Wildlife Research. 15 (1): 27–71. doi:10.1071/CWR9700027.
  6. ^ Brehm, Christian Ludwig (1845). "Das Stiftungsfest der naturforschenden Gesellschaft des Osterlandes in Altenburg, am 5 Julius 1843, und Etwas über die Vögel Griechenlands und Australiens". Isis (in German). 5: 323–58.
  7. ^ Australian Biological Resources Study (12 February 2010). . Australian Faunal Directory. Canberra, Australian Capital Territory: Department of the Environment, Water, Heritage and the Arts, Australian Government. Archived from the original on 4 November 2014. Retrieved 4 November 2014.
  8. ^ Latham, John (1781). A General Synopsis of Birds. Vol. 1. London: Benj. White. p. 369.
  9. ^ Gmelin, Johann Friedrich (1788). Systema naturae per regna tria naturae :secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis /Caroli a Linné. Vol. v. 1, pt. 1. Leipzig, Germany: Impensis Georg. Emanuel. Beer. p. 365.
  10. ^ Gould, John (1865). Handbook to The birds of Australia. Vol. v.1. London: self. p. 475.
  11. ^ Ogilvie-Grant, William Robert (1912). "The Crows of Australia". Emu. 12 (1): 44–45. Bibcode:1912EmuAO..12...44.. doi:10.1071/MU912044.
  12. ^ Mathews, Gregory M. (1912). "A Reference-List to the Birds of Australia". Novitates Zoologicae. 18: 171–455 [442]. doi:10.5962/bhl.part.1694.
  13. ^ Mathews, Gregory M. (1911). "Alterations in the Nomenclature of "Handbook of the Birds of Australia"". Emu. 10 (5): 317–26. Bibcode:1911EmuAO..10..317M. doi:10.1071/MU910317.
  14. ^ Vaurie, Charles (1962). Mayr, Ernst (ed.). Check-list of Birds of the World. Vol. 15 (XV ed.). Cambridge, Massachusetts: Harvard University Press. p. 261.
  15. ^ Schodde, Richard; Mason, I. J. (1999). Directory of Australian Birds: Passerines. Collingwood, Victoria: CSIRO. p. 609. ISBN 978-0-643-10293-4.
  16. ^ Gill, Frank; Donsker, David, eds. (2021). "Crows, mudnesters, melampittas, Ifrit, birds-of-paradise". World Bird List Version 11.2. International Ornithologists' Union. Retrieved 26 October 2021.
  17. ^ Alexander, W.B. (1933). "Popular Names for Australian Birds" (PDF). Emu. 33 (2): 110–11. Bibcode:1933EmuAO..33..110A. doi:10.1071/MU933110.
  18. ^ Troy, Jakelin (1993). The Sydney language. Canberra, ACT: self-published. p. 53. ISBN 978-0-646-11015-8.
  19. ^ a b c d e Jønsson, Knud A.; Fabre, Pierre-Henri; Irestedt, Martin (2012). "Brains, tools, innovation and biogeography in crows and ravens". BMC Evolutionary Biology. 12 (1): 72. Bibcode:2012BMCEE..12...72J. doi:10.1186/1471-2148-12-72. PMC 3480872. PMID 22642364.
  20. ^ Haring, Elisabeth; Däubl, Barbara; Pinsker, Wilhelm; Kryukov, Alexey; Gamauf, Anita (2012). "Genetic divergences and intraspecific variation in corvids of the genus Corvus (Aves: Passeriformes: Corvidae) – a first survey based on museum specimens" (PDF). Journal of Zoological Systematics and Evolutionary Research. 50 (3): 230–46. doi:10.1111/j.1439-0469.2012.00664.x.
  21. ^ a b c Rowley, Ian (1973). "The Comparative Ecology of Australian Corvids. VI. Why five species?". CSIRO Wildlife Research. 18 (1): 157–69. doi:10.1071/CWR9730157.
  22. ^ a b c d e f Higgins 2006, p. 692.
  23. ^ Higgins 2006, p. 714.
  24. ^ a b c d e Higgins 2006, p. 712.
  25. ^ a b c Higgins 2006, p. 713.
  26. ^ a b c d e f Higgins 2006, p. 691.
  27. ^ a b c d Higgins 2006, p. 711.
  28. ^ Higgins 2006, p. 693.
  29. ^ a b c Higgins 2006, p. 694.
  30. ^ a b Birds in Backyards. "Australian Raven". Retrieved 12 August 2007.
  31. ^ Australian Museum Online. "Crows and Ravens". from the original on 1 September 2007. Retrieved 12 August 2007.
  32. ^ a b c d e f g h Rowley, Ian (1973). "The Comparative Ecology of Australian Corvids. II. Social Organization and Behaviour". CSIRO Wildlife Research. 18 (1): 25–65. doi:10.1071/CWR9730025.
  33. ^ a b c d Higgins 2006, p. 696.
  34. ^ a b c Higgins 2006, p. 697.
  35. ^ . Rottnest Island Authority. Archived from the original on 14 June 2012. Retrieved 25 November 2011.
  36. ^ Higgins 2006, p. 695.
  37. ^ Birdlife Australia (2014). "Torresian Crow". Birds in Backyards. Birdlife Australia. Retrieved 18 October 2014.
  38. ^ a b Higgins 2006, p. 698.
  39. ^ a b c Higgins 2006, p. 699.
  40. ^ Higgins 2006, p. 708.
  41. ^ a b c Rowley, Ian (1971). "Movements and longevity of ravens in south-eastern Australia". CSIRO Wildlife Research. 16 (1): 49–72. doi:10.1071/CWR9710049.
  42. ^ Higgins 2006, p. 707.
  43. ^ a b Beruldsen, Gordon (2003). Australian Birds: Their Nests and Eggs. Kenmore Hills, Queensland: self. p. 384. ISBN 978-0-646-42798-0.
  44. ^ a b c Rowley, Ian; Braithwaite, L.W.; Chapman, Graeme S. (1973). "The Comparative Ecology of Australian Corvids. III. Breeding seasons". CSIRO Wildlife Research. 18 (1): 67–90. doi:10.1071/CWR9730067.
  45. ^ a b c d e f g h i j Rowley, Ian (1973). "The Comparative Ecology of Australian Corvids. IV. Nesting and the rearing of young to independence". CSIRO Wildlife Research. 18 (1): 91–129. doi:10.1071/CWR9730091.
  46. ^ a b c d Higgins 2006, p. 710.
  47. ^ a b Rowley, Ian; Vestjens, W.J.M. (1973). "The Comparative Ecology of Australian Corvids. V. Food". CSIRO Wildlife Research. 18 (1): 131–55. doi:10.1071/CWR9730131.
  48. ^ a b c Higgins 2006, p. 701.
  49. ^ Richardson, K.C. (1988). "Are Australian Corvids Nectarivorous?". Emu. 88 (2): 122–123. Bibcode:1988EmuAO..88..122R. doi:10.1071/MU9880122.
  50. ^ Higgins 2006, p. 700.
  51. ^ Stewart, Meredith E.; Perry, Ross; Raidal, Shane R. (2006). "Identification of a novel circovirus in Australian ravens (Corvus coronoides) with feather disease". Avian Pathology. 35 (2): 86–92. doi:10.1080/03079450600597345. PMID 16595298. S2CID 21073432.
  52. ^ Liu, Dandan; Brice, Belinda; Elliot, Aileen; Ryan, Una; Yang, Rongchang (2019). "Isospora coronoideae n. sp. (Apicomplexa: Eimeriidae) from the Australian raven (Corvus coronoides) (Passeriformes: Corvidae) (Linnaeus, 1758) in Western Australia". Parasitology Research. 118 (8): 2399–2408. doi:10.1007/s00436-019-06378-8. PMID 31222390. S2CID 195193276.
  53. ^ Temby, Ian. . Archived from the original on 17 September 2007. Retrieved 12 August 2007.(subscription required)
  54. ^ a b Rowley, Ian (1969). "An evaluation of predation by 'crows' on young lambs". CSIRO Wildlife Research. 14 (2): 153–79. doi:10.1071/CWR9690153.
  55. ^ Higgins 2006, p. 702.
  56. ^ Department of Environment and Conservation (12 December 2007). (PDF). Department of Agriculture and Food website. Perth, Western Australia: West Australian Government. Archived from the original (PDF) on 2014-11-29. Retrieved 13 November 2014.
  57. ^ Mudrooroo (1994). Aboriginal mythology: An A–Z Spanning the History of the Australian Aboriginal People from the Earliest Legends to the Present Day. London: Thorsons. pp. 35–36. ISBN 978-1-85538-306-7.
  58. ^ von Brandenstein; Carl Georg (1977). "Aboriginal Ecological Order in the South-West of Australia – Meaning and Examples". Oceania. 47 (3): 169–86. doi:10.1002/j.1834-4461.1977.tb01286.x. JSTOR 40330292.

Cited texts edit

External links edit

  • An Australian Raven call (two birds)
  • Explore Species: Australian Raven at eBird (Cornell Lab of Ornithology)


australian, raven, corvus, coronoides, passerine, bird, genus, corvus, native, much, southern, northeastern, australia, measuring, centimetres, length, black, plumage, beak, mouth, well, strong, grey, black, legs, feet, upperparts, glossy, with, purple, blue, . The Australian raven Corvus coronoides is a passerine bird in the genus Corvus native to much of southern and northeastern Australia Measuring 46 53 centimetres 18 21 in in length it has all black plumage beak and mouth as well as strong grey black legs and feet The upperparts are glossy with a purple blue or green sheen and its black feathers have grey bases The Australian raven is distinguished from the Australian crow species by its throat hackles which are prominent in adult birds Older adult individuals have white irises younger adults have white irises with an inner blue rim while younger birds have dark brown irises until fifteen months of age and hazel irises with an inner blue rim around each pupil until age two years and ten months Nicholas Aylward Vigors and Thomas Horsfield described the Australian raven in 1827 its species name coronoides highlighting its similarity with the carrion crow C corone Two subspecies are recognized which differ slightly in calls and are quite divergent genetically Australian ravenNear Kurnell New South Wales source source source An audio recording of an Australian raven Conservation statusLeast Concern IUCN 3 1 1 Scientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass AvesOrder PasseriformesFamily CorvidaeGenus CorvusSpecies C coronoidesBinomial nameCorvus coronoidesVigors amp Horsfield 1827SubspeciesC c coronoides C c perplexusSynonymsCorvus affinis Brehm 1845Corvus marianae Mathews 1911Corvus difficilis Stresemann 1943Corvus australis Gmelin 1788Corone australis Gmelin The preferred habitat is open woodland and transitional zones It has adapted well to urban environments and is a common city bird in Sydney Canberra Perth and Brisbane An omnivorous and opportunistic feeder it eats a wide variety of plant and animal material as well as food waste from urban areas In eastern Australia its range is strongly correlated with the presence of sheep and it has been blamed for killing lambs However this is very rare and the raven most often scavenges for afterbirth and stillborn 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 Contents 1 Taxonomy and naming 1 1 Evolution and systematics 2 Description 2 1 Vocalisations 3 Distribution and habitat 4 Behaviour 4 1 Breeding 4 2 Feeding 4 3 Parasites and predators 5 Relationship with humans 5 1 In Indigenous culture 6 Explanatory notes 7 References 7 1 Citations 7 2 Cited texts 8 External linksTaxonomy and naming editThe Australian raven was first described by Nicholas Aylward Vigors and Thomas Horsfield in 1827 when they reported George Caley s early notes on the species from the Sydney district 2 Its specific epithet coronoides crow shaped is derived from the Greek corone koronh crow and eidos eidos shape or form 3 The two naturalists regarded the Australian raven as very similar in appearance to the carrion crow C corone of Europe 4 though they noted it was larger with a longer bill They did not give it a common name 2 The location where the type specimen was collected is not recorded but thought to be in the Parramatta district 5 Christian Ludwig Brehm described Corvus affinis in 1845 6 later determined to be this species 7 In his 1865 Handbook to the Birds of Australia John Gould recognised only one species of corvid in Australia Corvus australis which he called the white eyed crow He used Johann Friedrich Gmelin s 1788 name a which predated Vigors and Horsfield s description 10 In 1877 Richard Bowdler Sharpe 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 5 Scottish naturalist William Robert Ogilvie Grant 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 11 Gregory Mathews 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 and forest raven as subspecies 12 Mathews had erected C marianae in 1911 as the name after declaring Corvus australis Gould to be preoccupied 13 French American ornithologist Charles Vaurie acted as first reviser under Article 24 of the International Code of Zoological Nomenclature 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 14 This has been followed by later authors 15 German ornithologist Erwin Stresemann 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 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 5 Australian raven has been designated the official name by the International Ornithologists Union IOC 16 Alternative names sometimes seen include southern raven southern crow and Kelly 4 the last thought to have alluded to the Kelly Gang 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 17 The term crow is colloquially applied to any or all species of Australian corvid 5 The Australian raven was called wugan by the local Eora and Darug inhabitants of the Sydney Basin 18 Evolution and systematics edit Evolution of Australasian corvidscrow ancestor bismarck crowtorresian crowlittle crowraven ancestor little ravenforest ravenAustralian raven eastern subspecies Australian raven western subspecies Phylogenetic tree based on Jonsson et al 2012 19 The Australian raven s closest relatives are the other two species of raven occurring in Australia the little raven 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 20 Subsequent multigene analysis using nuclear DNA by Jonsson 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 19 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 21 which molecular evidence indicates occurred in the early Pliocene epoch around 4 million years ago 19 The raven diverged into the ancestor of the forest and little ravens in the east and Australian raven in the west 21 this split occurring around 2 million years ago in the early Pleistocene 19 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 21 nbsp Subspecies perplexus Perth WA showing smaller hacklesTwo subspecies are recognised C c coronoides the nominate or eastern subspecies is found across most of eastern Australia 4 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 5 C c perplexus the western subspecies occurs from the head of the Great Australian Bight in South Australia westwards into Western Australia where its northern limits are Shark Bay and the mulga eucalypt boundary line 4 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 5 The western subspecies has a slightly lower pitched call than that of the eastern subspecies 22 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 23 Intermediate birds are found in the Eyre Peninsula Gawler Ranges and vicinity of Lake Eyre in South Australia 4 Description edit nbsp Adult in Sydney Shows bare skin on neck Measuring 46 53 cm 18 21 in in length with a 100 cm 39 in wingspan and weighing around the 650 g 1 43 lb the Australian raven is Australia s largest species of corvid 4 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 24 The tibia is fully feathered and the tarsus is long and the feet large and strong 25 It has white irises 24 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 26 The Australian raven has throat feathers hackles that are lanceolate with rounded tips while the other four species of Australian corvids have bifurcate tips though this can be difficult to see in the field 22 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 26 which can be up to 3 cm 1 2 in long 27 The heavy set beak is tipped with a slight hook 26 and is longer than the bird s head The wings are long and broad with the longest of its ten primary feathers 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 25 nbsp nbsp nbsp nbsp Changes in eye colour Clockwise from upper left Juvenile with dark irises Hyde Park Sydney Immature with hazel irises Centennial Park Sydney Adult with all white irises University of Sydney Maturing bird with white irises with slight blue ring Nowra 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 22 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 28 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 29 Juveniles resemble adults but lack throat hackles 27 and sometimes have a pink fleshy gape 30 The bill is shorter and shallower 26 its base can be pinkish and the tip can be light grey 24 The plumage is more ruffled and softer in appearance lacks the glossy highlights and often having a brown tinge 26 The bare skin on the throat is pink in birds that have recently left the nest 24 Eye colour varies with age gradually lightening from juvenile to adult 26 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 5 b Immature birds older than one year develop hackles 25 while some pink remains in the gape until the bird is two or three years of age 24 Vocalisations edit The territorial call of the Australian raven is a slow high ah ah aaaah similar to the near open front unrounded vowel IPA ae with the last note drawn out It uses this call to communicate with other Australian ravens in the area 31 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 29 This call becomes louder if trespassers encroach upon the Australian raven s territory 32 The five Australian species are very difficult to tell apart with the call being the easiest way to do so 4 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 29 source source source source source source source A raven Corvus coronoides coronoides produces an amusing variety of sounds 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 32 Distribution and habitat editThe Australian raven is common throughout eastern Australia 30 and southern Western Australia the populations being connected by a narrow strip across the Nullarbor Plain but it is rarer and more scattered in the north with isolated sightings in Cape York at Coen Windmill Creek and the Mitchell River 33 and becoming more common south of Rockhampton 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 being replaced there by the little raven It occurs across Victoria and eastern South Australia through the Eyre Peninsula and Nullarbor Plain into Western Australia across the state north to the Wooramel River 34 It is found on some offshore islands such as Rottnest Island 35 and Kangaroo Island 34 It is a rare vagrant to Lord Howe Island 34 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 dominated sclerophyll 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 22 the Australian raven is restricted to more forested areas while the latter species prefers more open areas 36 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 5 It co occurs with the forest raven in northeastern New South Wales from Port Stephens northwards 22 The Australian raven has adapted very well to human habitation in some cities and is the most common corvid in Canberra Sydney and Perth in Melbourne and Adelaide it is replaced by the little raven 22 and by the Torresian crow in Brisbane 37 Its large range abundance and increasing population mean it is classified as Least Concern on the IUCN Red List 1 Behaviour edit source source source source Rush Creek SE Queensland AustraliaDifficulties in distinguishing Australian corvids has hampered understanding of seasonal movements The Australian raven is thought to be largely sedentary with most movement of over 16 km 9 9 mi due to flocks of non breeding subadult birds 38 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 39 A single breeding pair and their brood can occupy a territory of up to around 120 hectares 300 acres and remains there year round though groups of ravens may enter this area to forage 38 Australian ravens will defend their territory by chasing dive bombing and occasionally striking the backs of birds of prey foxes or even people 40 They generally mate for life though occasionally one male has been found to be mated with two females in adjacent territories 32 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 41 No courtship behaviour has been observed and species that mate for life often lack elaborate courting displays 32 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 41 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 39 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 32 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 42 Breeding edit Australian ravens begin breeding once they are three years old 41 Breeding season is from July to September 43 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 44 Australian ravens generally nest in tall trees never near to the ground as some species do 33 The nest also functions as a lookout post and so tall or emergent trees are selected 45 The ravens occasionally nest on buildings telegraph poles 33 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 45 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 5 cm 2 0 in thick 46 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 30 60 cm 12 24 in long and 0 6 1 2 cm 1 4 1 2 in 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 45 The female develops a brood patch 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 44 Their lofty locations makes monitoring of Australian raven nests difficult 45 A clutch can comprise up to six eggs though usually four or five are laid with five being the most common number 45 Measuring 45 by 30 mm 1 3 4 by 1 1 4 in eggs are pale green or bluish green and splotched with darker olive brown and blackish markings 43 Eggs are quite variable and thus which Australian corvid laid them cannot be reliably identified 45 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 46 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 44 The chicks are altricial and nidicolous that is they are born helpless naked and blind and remain in the nest for an extended period 46 They have pink skin until 5 days of age when feathers under the skin turn it grey They lose their egg tooth at the same time 45 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 46 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 45 Feeding edit nbsp Australian raven scavenging roadkill with a wedge tailed eagleThe 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 spiders millipedes centipedes which ravens behead before eating grasshoppers cicadas and caterpillars especially of the family Noctuidae which are important in feeding nestlings Australian ravens sometimes eat yabbies Cherax destructor from the edges of dams Unusually for a ground feeding omnivore earthworms are rarely eaten Australian ravens have been reported killing birds of such size as young galahs Eolophus roseicapillus and starlings 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 47 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 32 as well as doing the same with hard biscuits to make them soggy and soft 48 Australian ravens are intelligent birds and like many other corvids have innovative methods of seeking out food 19 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 32 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 47 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 32 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 33 In one isolated study they were observed feeding on nectar from eucalypt flowers 49 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 50 Parasites and predators edit A circovirus 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 51 A species of Isospora given the name of I coronoideae was isolated from this species its only known host 52 Tick infestation is rare in the Australian raven with Ixodes holocyclus and Amblyomma triguttatum recorded Lice and hippoboscid flies have been recorded yet little researched and an infestation by the fly Passeromyia longicornis was recorded in one nest 45 The wedge tailed eagle Aquila audax preys on adult nestling and fledgling Australian ravens while the little eagle Hieraaetus morphnoides also takes nestlings and powerful owl Ninox strenua has been recorded killing adults 27 other birds of prey are seen as threats yet there is no evidence they have successfully preyed on the ravens The introduced red fox 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 45 The channel billed cuckoo Scythrops novaehollandiae has been recorded as a brood parasite 27 Relationship with humans editAustralian ravens sometimes die by being shot or poisoned generally by farmers Despite their fondness for roadkill fewer ravens are hit by vehicles than Australian magpies 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 39 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 53 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 54 Australian ravens mostly eat faeces often from the lamb s anus afterbirth or stillborn lambs 48 c Newborn lamb faeces is nutritious containing around 21 44 protein 9 37 fat and 10 30 carbohydrate It has the consistency of treacle 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 infection as these bacteria are present on raven bills 54 Ravens bring some benefits to agricultural areas as they clean away carrion and eat insects that are potentially damaging to crops 55 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 56 In Indigenous culture edit Main article Crow Australian Aboriginal mythology In Australian Aboriginal mythology Crow is a trickster culture hero and ancestral being In the Kulin nation in central Victoria 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 Legends relating to Crow have been observed in various Aboriginal language groups and cultures across Australia 57 To the Noongar 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 Cacatua tenuirostris respectively 58 Explanatory notes edit John Latham had described the south seas raven in 1781 with loose throat feathers and being found in the Friendly Isles in the South Seas but did not give it a binomial name 8 The place is thought to be Tonga 5 Gmelin gave it the name Corvus australis in the 13th edition of Systema naturae in 1788 9 Rowley and colleagues recorded iris colour changes of all five Australian corvid species raised in captivity 5 Lambing takes place in late winter with stillbirth rates around 20 so there is a supply of carrion around farming areas 48 References editCitations edit a b BirdLife International 2016 Corvus coronoides IUCN Red List of Threatened Species 2016 e T22706033A94047450 doi 10 2305 IUCN UK 2016 3 RLTS T22706033A94047450 en Retrieved 12 November 2021 a b Vigors Nicholas Aylward Horsfield Thomas 1827 A Description of the Australian Birds in the Collection of the Linnean Society with an Attempt at Arranging them According to their Natural Affinities Transactions of the Linnean Society of London 15 170 331 261 doi 10 1111 j 1095 8339 1826 tb00115 x Liddell Henry George Scott Robert 1980 A Greek English Lexicon Abridged ed Oxford Oxford University Press ISBN 978 0 19 910207 5 a b c d e f g Higgins 2006 p 690 a b c d e f g h i j Rowley Ian 1970 The Genus Corvus Aves Corvidae in Australia CSIRO Wildlife Research 15 1 27 71 doi 10 1071 CWR9700027 Brehm Christian Ludwig 1845 Das Stiftungsfest der naturforschenden Gesellschaft des Osterlandes in Altenburg am 5 Julius 1843 und Etwas uber die Vogel Griechenlands und Australiens Isis in German 5 323 58 Australian Biological Resources Study 12 February 2010 Species Corvus coronoides coronoides Vigors amp Horsfield 1827 Australian Faunal Directory Canberra Australian Capital Territory Department of the Environment Water Heritage and the Arts Australian Government Archived from the original on 4 November 2014 Retrieved 4 November 2014 Latham John 1781 A General Synopsis of Birds Vol 1 London Benj White p 369 Gmelin Johann Friedrich 1788 Systema naturae per regna tria naturae secundum classes ordines genera species cum characteribus differentiis synonymis locis Caroli a Linne Vol v 1 pt 1 Leipzig Germany Impensis Georg Emanuel Beer p 365 Gould John 1865 Handbook to The birds of Australia Vol v 1 London self p 475 Ogilvie Grant William Robert 1912 The Crows of Australia Emu 12 1 44 45 Bibcode 1912EmuAO 12 44 doi 10 1071 MU912044 Mathews Gregory M 1912 A Reference List to the Birds of Australia Novitates Zoologicae 18 171 455 442 doi 10 5962 bhl part 1694 Mathews Gregory M 1911 Alterations in the Nomenclature of Handbook of the Birds of Australia Emu 10 5 317 26 Bibcode 1911EmuAO 10 317M doi 10 1071 MU910317 Vaurie Charles 1962 Mayr Ernst ed Check list of Birds of the World Vol 15 XV ed Cambridge Massachusetts Harvard University Press p 261 Schodde Richard Mason I J 1999 Directory of Australian Birds Passerines Collingwood Victoria CSIRO p 609 ISBN 978 0 643 10293 4 Gill Frank Donsker David eds 2021 Crows mudnesters melampittas Ifrit birds of paradise World Bird List Version 11 2 International Ornithologists Union Retrieved 26 October 2021 Alexander W B 1933 Popular Names for Australian Birds PDF Emu 33 2 110 11 Bibcode 1933EmuAO 33 110A doi 10 1071 MU933110 Troy Jakelin 1993 The Sydney language Canberra ACT self published p 53 ISBN 978 0 646 11015 8 a b c d e Jonsson Knud A Fabre Pierre Henri Irestedt Martin 2012 Brains tools innovation and biogeography in crows and ravens BMC Evolutionary Biology 12 1 72 Bibcode 2012BMCEE 12 72J doi 10 1186 1471 2148 12 72 PMC 3480872 PMID 22642364 Haring Elisabeth Daubl Barbara Pinsker Wilhelm Kryukov Alexey Gamauf Anita 2012 Genetic divergences and intraspecific variation in corvids of the genus Corvus Aves Passeriformes Corvidae a first survey based on museum specimens PDF Journal of Zoological Systematics and Evolutionary Research 50 3 230 46 doi 10 1111 j 1439 0469 2012 00664 x a b c Rowley Ian 1973 The Comparative Ecology of Australian Corvids VI Why five species CSIRO Wildlife Research 18 1 157 69 doi 10 1071 CWR9730157 a b c d e f Higgins 2006 p 692 Higgins 2006 p 714 a b c d e Higgins 2006 p 712 a b c Higgins 2006 p 713 a b c d e f Higgins 2006 p 691 a b c d Higgins 2006 p 711 Higgins 2006 p 693 a b c Higgins 2006 p 694 a b Birds in Backyards Australian Raven Retrieved 12 August 2007 Australian Museum Online Crows and Ravens Archived from the original on 1 September 2007 Retrieved 12 August 2007 a b c d e f g h Rowley Ian 1973 The Comparative Ecology of Australian Corvids II Social Organization and Behaviour CSIRO Wildlife Research 18 1 25 65 doi 10 1071 CWR9730025 a b c d Higgins 2006 p 696 a b c Higgins 2006 p 697 Birds of Rottnest Island Rottnest Island Authority Archived from the original on 14 June 2012 Retrieved 25 November 2011 Higgins 2006 p 695 Birdlife Australia 2014 Torresian Crow Birds in Backyards Birdlife Australia Retrieved 18 October 2014 a b Higgins 2006 p 698 a b c Higgins 2006 p 699 Higgins 2006 p 708 a b c Rowley Ian 1971 Movements and longevity of ravens in south eastern Australia CSIRO Wildlife Research 16 1 49 72 doi 10 1071 CWR9710049 Higgins 2006 p 707 a b Beruldsen Gordon 2003 Australian Birds Their Nests and Eggs Kenmore Hills Queensland self p 384 ISBN 978 0 646 42798 0 a b c Rowley Ian Braithwaite L W Chapman Graeme S 1973 The Comparative Ecology of Australian Corvids III Breeding seasons CSIRO Wildlife Research 18 1 67 90 doi 10 1071 CWR9730067 a b c d e f g h i j Rowley Ian 1973 The Comparative Ecology of Australian Corvids IV Nesting and the rearing of young to independence CSIRO Wildlife Research 18 1 91 129 doi 10 1071 CWR9730091 a b c d Higgins 2006 p 710 a b Rowley Ian Vestjens W J M 1973 The Comparative Ecology of Australian Corvids V Food CSIRO Wildlife Research 18 1 131 55 doi 10 1071 CWR9730131 a b c Higgins 2006 p 701 Richardson K C 1988 Are Australian Corvids Nectarivorous Emu 88 2 122 123 Bibcode 1988EmuAO 88 122R doi 10 1071 MU9880122 Higgins 2006 p 700 Stewart Meredith E Perry Ross Raidal Shane R 2006 Identification of a novel circovirus in Australian ravens Corvus coronoides with feather disease Avian Pathology 35 2 86 92 doi 10 1080 03079450600597345 PMID 16595298 S2CID 21073432 Liu Dandan Brice Belinda Elliot Aileen Ryan Una Yang Rongchang 2019 Isospora coronoideae n sp Apicomplexa Eimeriidae from the Australian raven Corvus coronoides Passeriformes Corvidae Linnaeus 1758 in Western Australia Parasitology Research 118 8 2399 2408 doi 10 1007 s00436 019 06378 8 PMID 31222390 S2CID 195193276 Temby Ian Predatory Birds Archived from the original on 17 September 2007 Retrieved 12 August 2007 subscription required a b Rowley Ian 1969 An evaluation of predation by crows on young lambs CSIRO Wildlife Research 14 2 153 79 doi 10 1071 CWR9690153 Higgins 2006 p 702 Department of Environment and Conservation 12 December 2007 Fauna Note No 16 Australian Raven PDF Department of Agriculture and Food website Perth Western Australia West Australian Government Archived from the original PDF on 2014 11 29 Retrieved 13 November 2014 Mudrooroo 1994 Aboriginal mythology An A Z Spanning the History of the Australian Aboriginal People from the Earliest Legends to the Present Day London Thorsons pp 35 36 ISBN 978 1 85538 306 7 von Brandenstein Carl Georg 1977 Aboriginal Ecological Order in the South West of Australia Meaning and Examples Oceania 47 3 169 86 doi 10 1002 j 1834 4461 1977 tb01286 x JSTOR 40330292 Cited texts edit Higgins Peter Jeffrey Peter John M Cowling S J eds 2006 Handbook of Australian New Zealand and Antarctic Birds Vol 7 Boatbill to Starlings Melbourne Victoria Oxford University Press ISBN 978 0 19 553996 7 External links edit nbsp Wikimedia Commons has media related to Corvus coronoides nbsp Wikispecies has information related to Corvus coronoides An Australian Raven call two birds Explore Species Australian Raven at eBird Cornell Lab of Ornithology Retrieved from https en wikipedia org w index php title Australian raven amp oldid 1188140717, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.