House crow

House crow
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Corvidae
Genus: Corvus
Species: C. splendens
Binomial name
Corvus splendens
Vieillot, 1817

The house crow (Corvus splendens), also known as the Indian, greynecked, Ceylon or Colombo crow,[2] is a common bird of the crow family that is of Asian origin but now found in many parts of the world, where they arrived assisted by shipping. It is between the jackdaw and the carrion crow in size (40 cm (16 in) in length) but is slimmer than either. The forehead, crown, throat and upper breast are a richly glossed black, whilst the neck and breast are a lighter grey-brown in colour. The wings, tail and legs are black. There are regional variations in the thickness of the bill and the depth of colour in areas of the plumage.

Taxonomy

The nominate race C. s. splendens is found in Pakistan, India, Nepal and Bangladesh and has a grey neck collar. The subspecies C. s. zugmayeri is found in the dry parts of South Asia and Iran and has a very pale neck collar. The subspecies C. s. protegatus is found in southern India, the Maldives (sometimes separated as maledivicus) and Sri Lanka and is darker grey. C. s. insolens, found in Myanmar, is the darkest form and lacks the grey collar.[3]

Distribution and habitat

It has a widespread distribution in southern Asia, being native to Nepal, Bangladesh, India, Pakistan, Sri Lanka, Maldives and Laccadive Islands, South West Thailand and coastal southern Iran. It was introduced to East Africa around Zanzibar (about 1897)[4] and Port Sudan. It arrived in Australia via ship but has up to now been exterminated. Recently, it has made its arrival in Europe and has been breeding in the Dutch harbour town Hook of Holland since 1998. An individual has been present in Cork Harbour on the south coast of Ireland since early September 2010.[5]

In the New World, a small population of house crows is established in the area around St. Petersburg, Florida.[6]

It is associated with human settlements throughout its range, from small villages to large cities. In Singapore, there was a density of 190 birds/km2 in 2001 with efforts to suppress the population in planning.[7][8]

Due to a human population explosion in the areas it inhabits, this species has also proportionately multiplied. Being an omnivorous scavenger has enabled it to thrive in such circumstances.

The invasive potential for the species is great all over the tropics. This species is able to make use of resources with great flexibility and appears to be associated with humans, and no populations are known to exist independently of humans.[9]

Behaviour

House crow resting in shadows on a rooftop with slaughterhouse refuse to eat.
Parents feeding nestlings
Nest with eggs

Diet

House crows feed largely on refuse around human habitations, small reptiles and mammals,[10] and other animals such as insects and other small invertebrates, eggs, nestlings, grain and fruits. House crows have also been observed swooping down from the air and snatching baby squirrels. Most food is taken from the ground, but also from trees as opportunity arises. They are highly opportunistic birds and given their omnivorous diet, they can survive on nearly anything that is edible. These birds can be seen near marketplaces and garbage dumps, foraging for scraps. They have also been observed to eat sand after feeding on carcass.[11]

Nesting

At least some trees in the local environment seem to be necessary for successful breeding although house crows occasionally nest on telephone towers.[12] It lays 3–5 eggs in a typical stick nest, and occasionally there are several nests in the same tree. In South Asia they are parasitized by the Asian koel. Peak breeding in India as well as Peninsular Malaysia is from April to July. Large trees with big crowns are preferred for nesting.[13]

Roosting

House crows roost communally near human habitations and often over busy streets. A study in Singapore found that the preferred roost sites were in well-lit areas with a lot of human activity, close to food sources and in tall trees with dense crowns that were separated from other trees. The roost sites were often enclosed by tall buildings.[14]

Voice

The voice is a harsh kaaa-kaaa.[3]

Relationship to humans

It is suspected that paramyxoviruses, such as PMV 1 that causes of Newcastle disease[15] may be spread by Corvus splendens. Outbreaks of Newcastle disease in India were often preceded by mortality in crows.[16] They have also been found to carry Cryptococcus neoformans, which can cause cryptococcosis in humans.[17]

House crows in Tanzania curiously showed an absence of blood parasites, although some species such as Trypanosoma corvi have been first described from this species.[18] Pathologist T.R. Lewis expressed surprise at the numbers of haematozoa present in the blood of house crows from Calcutta.[19]

References

  1. ↑ BirdLife International (2012). "Corvus splendens". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. ↑ "House crow: animal pest alert". agric.wa.gov. Government of Western Australia: Department of Agriculture and Food. Retrieved 30 October 2015.
  3. 1 2 Rasmussen, PC & JC Anderton (2005) Birds of South Asia: The Ripley Guide. Smithsonian Institution and Lynx Edicions. Vol 2. p.598
  4. ↑ Cooper, John E. (1996). "Health studies on the Indian house crow (Corvus splendens)". Avian Pathology. 25 (2): 381–386. doi:10.1080/03079459608419148.
  5. ↑ Ottens, G. (2003) Background and development of the Dutch population of House Crows Corvus splendens. Limosa 76(2):69-74
  6. ↑ Pranty, W. 2004. Florida’s exotic avifauna: a preliminary checklist. - Birding, August 2004: 362:372.
  7. ↑ Brook, B.W., Sodhi, N.S., Soh, M.C.K., Lim, H.C. (2003) Abundance and projected control of invasive house crows in Singapore. Journal of Wildlife Management 67(4):808-817
  8. ↑ Ryall, C., 2002. Further records of range extension in the House Crow Corvus splendens. BOC Bulletin 122(3): 231-240
  9. ↑ Nyari, A., Ryall, C. and Peterson, A. T. 2006. Global invasive potential of the house crow Corvus splendens based on ecological niche modeling. J. Avian Biol. 37:306-311.
  10. ↑ Mikula, P.; Morelli, F.; Lučan, R. K.; Jones, D. N.; Tryjanowski, P. (2016). "Bats as prey of diurnal birds: a global perspective". Mammal Review. doi:10.1111/mam.12060.
  11. ↑ Amey Jayesh Kambli (2004). "Geophagy by three species of crows near carcass dumping ground at Jodhpur, Rajasthan". Newsletter for Ornithologists. 1 (5): 71.
  12. ↑ Lamba, B.S. 1963. The nidification of some common Indian birds. Part I. J. Bombay Nat. Hisl. Soc. 60:121-133
  13. ↑ Soh MCK, NS Sodhi, RKH Seoh, BW Brook (2002) Nest site selection of the house crow (Corvus splendens), an urban invasive bird species in Singapore and implications for its management. Landscape and Urban planning 59:217-226
  14. ↑ Kelvin S.-H. Peh and Navjot S. Sodhi (2002) Characteristics of Nocturnal Roosts of House Crows in Singapore. The Journal of Wildlife Management 66(4):1128-1133
  15. ↑ Roy, P., Venugopalan, A.T., Manvell, R. 1998 Isolation of Newcastle disease virus from an Indian house crow. Tropical animal health and production 30 (3):177-178
  16. ↑ Blount, W.P. (1949). Diseases of Poultry. (London, Balliere, Tindall and Cox).
  17. ↑ S. Gokulshankar, S. Ranganathan, M. S. Ranjith and A. J. A. Ranjithsingh (2004) Prevalence, serotypes and mating patterns of Cryptococcus neoformans in the pellets of different avifauna in Madras, India. Mycoses, 47:310–314
  18. ↑ Dirie, M.F., Ashford, R.W., Mungomba, L.M., Molyneux, D.H. & Green, E.E. (1990). Avian trypanosomes in Simulium and sparrowhawks (Accipiter nisus). Parasitology, 101,243-247.
  19. ↑ Lewis, Timothy Richards (1879). The microscopic organisms found in the blood of man and animals, and their relation to disease. Calcutta: Government Press. p. 71.
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