Introduction
The house crow (Corvus splendens) is also known as the Indian, grey-necked, Ceylon or Colombo crow. It is not native to Australia but has been transported here on numerous occasions on ships. The house crow has significant potential to establish populations in Australia and become a pest, so it is important to report any found in the wild.
Description
The house crow is 42 to 44 cm in length (body and tail). It has black plumage that appears glossy with a metallic greenish blue-purple sheen on the forehead, crown, throat, back, wings and tail. In contrast, the nape, neck and lower breast are paler in colour (grey tones) and not glossed. The bill is black and the upper beak is strongly curved. The forehead is sloped and the eyes are dark brown. Legs and feet are black.
Male and female birds look similar, although males are slightly larger. Immature birds have little or no sheen to their plumage.
Mistaken identity
Australian native crows and ravens (together called ‘corvids’) look similar in body shape to the house crow. However, these native corvids are different in that they have all-black plumage and white eyes when adult. Immature birds initially have dark eyes like the house crow, but they lighten to white as the birds mature. The native corvids include:
- Australian raven (all states except Tasmania)
- Little crow (occurs from inland eastern Australia to the west coast)
- Forest raven (the only corvid in Tasmania plus small populations in South Australia, Victoria and New South Wales)
- Torresian crow (northern Australia).
The house crow is smaller and more slender than all native corvids (about 10 cm smaller than the Australian raven). Its voice is a short, repeated caw-caw-caw which is very different from the drawn-out aah-aah-aah-aaaaahhhh of the Australian raven or the nark-nark-nark of the little crow and the calls of other native corvids. The house crow also lacks the long floppy throat feathers (called hackles) of the Australian raven.
Distribution
The house crow is well-known throughout much of its natural range. It occurs in central Asia from southern coastal Iran through Pakistan, India, Tibet, Myanmar and Thailand to southern China. It also occurs in Sri Lanka and on the nearby Laccadive and Maldive islands.
Introduced populations occur in coastal areas bordering the Indian Ocean; in South Africa, Mozambique, Tanzania, Kenya, Somalia, Ethiopia, Mauritius and the Seychelle islands.
Along the Red Sea and the Suez Canal it has been introduced to Sudan, Egypt, Israel, Jordan, Saudi Arabia, Kuwait, the United Arab Emirates, Yemen and Oman.
Introduced populations also occur in Malaysia, Singapore, Hong Kong and the Netherlands.
Habitat
In its natural and introduced range the house crow occupies most types of urban and rural habitats including towns and cities, farmlands, forest edge, sea ports, mangroves and shorelines. It lives in close association with man and is nearly always found near human settlement.
Reproduction, food and behaviour
House crow nests are untidy platforms built of twigs and occasionally wire, usually higher than 3 m above the ground.
The nest can be built in tree forks, buildings, streetlights or pylons. The house crow is an omnivorous scavenger, eating almost anything including grains, fruits, nuts, nectar, insects, fish, and small animals. Eggs and nestlings, food scraps, garbage, offal and carrion are also eaten readily. In some countries the house crow has a role as a domestic scavenger.
This sedentary and gregarious bird has a reputation for intelligence and boldness. Small and large flocks congregate at communal roosts (several thousand birds have been recorded), and food sources at rubbish dumps, abattoirs and markets.
In the wild, the house crow lives for about 6 years but in captivity it can live for 20 years.
Damage by the house crow
The house crow is a major pest of agriculture, raiding crops such as wheat, maize and sunflower. It causes severe damage to vegetables and fruit crops including mango, guava, pawpaw, fig, apple, pear, grape and stone fruit. The house crow will attack and can kill poultry, new-born calves and kid goats. Adult livestock are harassed and can be injured.
In some countries the house crow is considered a major pest of the environment, preying on the chicks and eggs of native birds, destroying nests and harassing birds and other animals. Some native birds in Kenya have been displaced by the introduced house crow.
The house crow causes considerable nuisance to people as it scatters rubbish, damages electrical wiring, blocks drainpipes and interferes with power supplies. Large flocks are very noisy, make a mess with droppings, and pose a bird strike hazard to aircraft.
The house crow may spread disease to people and it can attack people to steal food and shiny jewellery.
Many control programs overseas have attempted to eradicate the house crow or lessen the damage it causes. Methods used include shooting and scaring with firearms, trapping, chemical repellents, poison baits and habitat modification. Other methods include destruction of nests and paid-bounties on crow eggs and chicks.
Potential to be a pest in Australia
The house crow is rated as being highly likely to establish populations in Australia and become a pest of agriculture, the environment and public amenity.
A scientific risk assessment conducted by the Department of Primary Industries and Regional Development in Western Australia and endorsed by the national Invasive Plants and Animals Committee indicates that the house crow poses an extreme threat (the highest of 4 categories) to Australia. Part of the assessment showed that the climates of the house crow’s overseas range and Australia are very similar.
It is therefore important to quickly remove birds found in Australia. Introduced populations could threaten biodiversity, with native corvids and many small animals potentially at risk.
Crops including cereals, oilseeds and fruits could be at risk. Livestock production may be subject to loss of fodder, spoilage of food at feedlots or attack from the house crow. The house crow may also add to the nuisance already caused in urban areas by native corvids and other birds.
Birds in the wild
The house crow is prohibited from import into Australia but it is occasionally transported here on ships. It has been found in Victoria but more commonly in Western Australia due to the state being close to ports in southern Asia where the house crow occurs.
Declared pest category
The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in WA. Use the links on this page to reach house crow in WAOL.
Reporting
To help prevent the house crow from establishing in the wild and becoming a pest in Australia, it is essential to immediately report all sightings so that any house crow reported can then be removed humanely.
Report suspected sightings to::
Pest and Disease Information Service
Phone: 9368 3080
Email: padis@dpird.wa.gov.au