Australian Raven

## Description

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.

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, and Perth. 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.

## Appearance

The Australian raven has all-black plumage, beak, and mouth, as well as strong grey-black legs and feet. The upper parts are glossy, with a purple, blue, or green sheen, and its black feathers have grey bases. 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 flight feathers almost reaching the end of the tail when the bird is at rest.

## Distribution

Australian ravens are native to much of southern and northeastern Australia. These birds can be found in a wide range of natural and modified habitats. They require available water and trees (or buildings) to roost in or perch on. Preferred habitats include eucalypt-dominated sclerophyll forests, and farmland adjacent to trees. They are also found in heath, mangroves, on the shoreline, and on beaches. Australian ravens have adapted well to urban environments and are common city birds in Sydney, Canberra, and Perth.

## Behavior

Australian ravens are largely sedentary and territorial birds. They are usually seen in pairs or small flocks of 8-30 birds that stay within an area of around 260 square kilometers; larger flocks of up to 300 birds may travel hundreds of kilometers seeking food. A single breeding pair and their brood can occupy a certain territory and remains there year-round, though groups of ravens may enter this area to forage. Australian ravens defend their territory by chasing, dive-bombing, and occasionally striking the backs of birds of prey, foxes, or even people. These birds generally move by walking around on the ground, though do hop when hurrying. They preen themselves frequently, particularly when roosting in the middle of the day. Australian ravens are intelligent birds and have innovative methods of seeking out food. They forage in the early morning or late afternoon and rest in the hotter part of the day. 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 may also use fence posts as anvils to bash snails against before eating them. Australian ravens communicate using 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. When in flocks ravens make a single high-pitched 'caa' while flying over another territory as a transit call to signify they are just passing through. They will also give a longer 'caa' to signify their return to the nest to their mate.

## Diet

Australian ravens are omnivores, though they generally eat more meat. Their diet contains a high proportion of insects, plant items, and flesh in winter. Invertebrates commonly eaten include spiders, millipedes, centipedes (which ravens behead before eating), grasshoppers, cicadas, and caterpillars (important food for nestlings). Australian ravens may also kill birds of such size as young galahs and starlings and most mammals are eaten as carrion. In urban areas, these birds eat food scraps in school playgrounds, rubbish tips, bins outside supermarkets or restaurants, abattoirs, piggeries, and farmyards.

## Reproduction

Australian ravens are monogamous; they generally mate for life, though occasionally one male may mate with two females in adjacent territories. If the female dies, the male maintains the territory and finds another mate, while if the male bird is lost, the female abandons the territory. Breeding season usually occurs from July to September. The birds generally nest in tall trees as the nest also functions as a lookout post. In areas lacking in tall trees, ravens may sometimes nest on buildings, telegraph poles, or tall windmills. 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 in) thick. The female lays a clutch of 4 to 6 eggs and incubates them alone over roughly 20 days. The chicks are born helpless (altricial), 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 grey; they lose their egg tooth at the same time. Their eyes are fully open by 11 to 12 days, and they are fully feathered by 35-36 days old. The young leave the nest at 40-45 days of age and stay with their parents for 3 to 4 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 Australian ravens begin breeding once they are three years old.

## Population

### Population threats

The main causes of Australian ravens' mortality include hunting or poisoning - generally by farmers, and the birds are also often hit by vehicles. In Western Australia, ravens are classified as a Declared Pest of Agriculture and they can be shot on private land as they damage crops or stock.

### Population number

The IUCN Red List and other sources don’t provide the total number of the Australian raven population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are increasing.

### Ecological niche

Australian ravens play an important role in the ecosystem they live in. These birds bring some benefits to agricultural areas as they clean away carrion and eat insects that are potentially damaging to crops.

## Fun Facts for Kids

The Australian raven is also known as the southern raven, southern crow, and Kelly. It was also called 'wugan' by the local Eora and Darug inhabitants of the Sydney Basin.

The territorial call of the Australian raven is a slow, high 'ah-ah-aaaah'. It uses this call to communicate with other Australian ravens in the area. When giving this call, the bird takes a horizontal posture, holding its head forward and body parallel to the ground, while usually perched on a prominent position.

Around three weeks before laying eggs, the female Australian raven develops a brood patch; it's a patch of bare skin on the bird's underparts that reddens and becomes much more extensive. The skin itself is wrinkled and gets re-feathered only after the breeding season has finished.

During foraging Australian ravens could take golf balls from fairways, possibly mistaking them for eggs.

Australian ravens can pack shredded meat in their mouth under their tongue. They also occasionally hide a carrion or a killed animal in a hole nearby to store it.

Australian ravens were even observed feeding on nectar from eucalypt flowers.

Australian ravens drink water frequently, up to ten times a day in hot weather. They may dunk pieces of meat in water before eating them, and often do the same with hard biscuits to make them soggy and soft.

In Australian Aboriginal mythology, Crow is a trickster, cultural 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. Legends relating to Crow have been observed in various Aboriginal language groups and cultures across Australia.