Common names: House Crow, Indian House Crow, Grey-necked Crow, Town Crow, Ceylon Crow, Colombo Crow and Grey-necked Crow (Eng.); huiskraai (Afr.) (Shivambu et al 2020a).
Description/How to recognize a House Crow
A House Crow is a slender bird with a head to tail length of about 40 cm and black-brown eyes. it has a black head with grey neck/collar;sides of head and the breast varies in different races; glossy black back and wings, and black legs. It has a relatively large bill and long legs. An adult House Crow weighs approximately 245 to 371 g. Male and females are similar in appearance however, males are slightly larger. Their juveniles are duller than adults (Madge and Burn 1994; Dean 2005).
A House Crow gets around by flying. However, in countries such as Tanzania (Shimba & Jonah 2017), Socotra Island (Yemen) in 1995, and Malaysia (Suliman et al. 2011) it was reported that they were introduced unintentionally, often through ships as hitchhikers.
A House Crow makes a loud and harsh ‘kaaw kaaaw/kaaa kaaa’ sound/call.
House Crowsare native to and widely distributed in Southern Asia, which includes Nepal, Bangladesh, India, Pakistan, Sri Lanka, Maldives, Laccadive, Myanmar, Qatar, Singapore, and southwest Thailand and coastal southern Iran (Meininger et al. 1980; Nyári et al. 2006; Ryall 2010). However, it was introduced in South Africa, Durban in 1972 and Cape Town in 1977 (Allan & Davies 2005). It is distributed in Durban and northwards from Durban to Richards Bay. It is also found in East London and Cape Town (Nxele & Shivambu 2018).
House Crows inhabit areas associated with human settlement in both urban and rural areas (Suliman et al. 2011). They are also distributed in disturbed areas, coastal settlements and farmlands (Akram et al. 2013; Shimba and Jonah 2015). They nest in telephone lines, television antenae and some trees across their range (Behrouzi-Rad 2010). They are known to be competitors of other corvids as well as other native birds for food, nesting sites and space (Ryall 1992; Chongomwa 2011).
House crows are omnivorous and opportunistic animals. They predate on small vertebrates and invertebrates, which include birds, mammals and reptiles. They also feed on fruits and raid crops (Suliman et al. 2011; Koul & Sahi 2013). They are considered as scavengers in the cities where they feed on human food leftovers and drink water from swimming pools (Brook et al. 2003; Wilson et al. 2013; Fraser et al. 2015).
Sex and life cycles
Sex and family life: House Crows mate through sexual reproduction in which they produce a clutch size of three to five pale, blue-green, speckled with streaked brown eggs. They produce two clutches per year. They breed from March/April to July/August and in some areas, they breed between October and January (Allan & Davies 2005; Dean 2005). Two to threeeggs hatched successfully per clutch(Allan and Davies 2005; Dean 2005). The nest is incubated by both sexes between 16 -and17 days, however, females mainly incubate at night (Snow et al. 1997; Dean 2005).
The big picture
A House Crow is regarded as an invasive species in South Africa because it mostly affects the ecosystem negatively (Allan & Davies 2005; Nxele & Shivambu 2018; Shivambu et al. 2020b).
Friends and Foes
The House Crow is regarded as a competitor with other corvids in its native region. In South Africa, it is regarded as a predator that feeds on other small invertebrates and vertebrates, which might lead to a reduction of South African native species.
They have a high reproduction potential. They are highly adaptable to different environments,are highly mobile, they are omnivorous opportunists, and they benefit from human presence.
The poorer world without me
In some areas, they were introduced to control agricultural and house pests such as rodents and to provide cleaning up services / garbage elimination through scavenging in cities (Brook et al. 2003; Fraser et al. 2015).
Conservation status and what the future holds
The House Crow is listed as Least Concern on the IUCN Red List of Threatened Species. In South Africa they are listed as a Category 1a invasive species in the National Environmental Management: Biodiversity Act, Alien and Invasive Species Regulations.
Other (native) species from the same genus found in South Africa are Pied Crow (Corvus albus), White-necked Raven (Corvus albicollis) and Cape Crow (Corvus capensis).
Scientific Name and Classification:
The House Crow, Corvus splendens Vieillot, 1817, has five subspecies, namely: C. s. splendens, C. s. zugmayeri, C. s. protegatus, C. s. maledivicus, and C. s. insolens) (Dean 2005). Specimens are usually identified only to species level as Corvus splendens due to a lack of the genetic studies needed to reveal which subspecies it belongs to (Madge and Burn 1994; Ottens 2003).
Species: C. splendens Vieillot, 1817
References and further reading
- Allan, D.G. & Davies, G.B. 2005. Breeding biology of House Crow (Corvus splendes) in Durban, South Africa. Ostrich 76: 21–31.https://doi.org/10.2989/0030650509485469
- Akram, N., Khan, H.A. & Javed, M. 2013. Inhibiting the House Crow (Corvus splendens) damage on maize growth stages with reflecting ribbons in farmland. Journal of Animal and Plant Sciences 23: 182–189.
- Behrouzi-Rad, B. 2010. Population estimation and breeding biology of the House Crow Corvus splendens on Kharg Island, Persian Gulf. Podoces 5: 87–94.
- BirdLife International. 2020. Species factsheet: Corvus splendens. Downloaded from http://www.birdlife.org on 20/04/2020.
- 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: 808–817.
- Chongomwa, M.M. 2011. Mapping locations of nesting sites of the Indian House Crow in Mombasa. Journal of Geography and Regional Planning 4: 87–97.
- Dean, W.R.J. 2005. House Crow. In Hockey, P.A.R., Dean, W.R.J. and Ryan, P. (eds), Roberts Birds of southern Africa, 7th edn. Trustees of the John Voelcker bird book fund, Cape Town, pp. 721–722.
- Fraser, D.L., Aguilar, G., Nagle, W., Galbraith, M. & Ryall, C. 2015. The House Crow (Corvus splendens): a threat to New Zealand? ISPRS International Journal of Geo-Information 4: 725–740.
- Global Invasive Species Database. 2020. Species profile: Corvus splendens. Downloaded from http://www.iucngisd.org/gisd/species.php?sc=1199 on 20/04/2020.
- Koul, S. & Sahi, D.N. 2013. Feeding ecology of House Crow (Corvus splendens) in open agricultural fields in Jammu (J&K), India. International Research Journal of Environment Sciences 2: 85–87.
- Madge, S. & Burn, H. 1994. Crows and jays: a guide to the crows, jays and magpies of the world. Christopher Helm London, United Kingdom.
- Meininger, P.L., Mullie, W.C. & Bruun, B. 1980. The spread of the House Crow, Corvus splendens, with special reference to the occurrence in Egypt. Le Gerfaut 70: 245–250.
- Nyári, Á., Ryall, C. & Townsend Peterson, A. 2006. Global invasive potential of the House Crow Corvus splendens based on ecological niche modelling. Journal of Avian Biology 37: 306–311.
- Nxele, B.J. & Shivambu, C.T. 2018. House Crow (Corvus splendens) Eradication Measures from eThekwini Municipality, KwaZulu-Natal, South Africa. J Biodivers Manage Forestry 7:2.
- Ottens, G. 2003. Background and development of the Dutch population House Crows Corvus splendens. Limosa 76:69–74.
- Ryall, C. 1992. Predation and harassment of native bird species by the Indian House Crow Corvus splendens in Mombasa, Kenya. Scopus 16: 1–8.
- Ryall, C. 2010. Further records and updates of range extension in House Crow Corvus splendens. Bulletin of British Ornithologists Club 130:246–254.
- Shimba, M.J. & Jonah, F.E. 2017. Nest success of the Indian House Crow Corvus splendens: an urban invasive bird species in Dar es Salaam, Tanzania. Ostrich 88: 27–31.
- Shivambu, C.T., Maligana, N. & Downs, C.T. 2020a. House Crows (Corvus splendens Vieillot, 1817). In Downs, C.T. & Hart, L.A. (eds), Global trends and impacts of alien invasive birds. CABI, Wallingford, UK.
- Shivambu, C.T., Maligana, N. & Downs, C.T. 2020b. Impact assessment of seven alien invasive bird species already introduced to South Africa. Biological Invasion https://doi.org/10.1007/s10530-020-02221-9(0123456789().,-volV() 0123458697().,-vol V
- Snow, D.W., Perrins, C.M., Hillcoat, B., Gillmor, R. & Roselaar, C.S. 1997.p The birds of the Western Palearctic, concise ed. Oxford University Press, Amsterdam, Netherlands.
- Suliman, A.S., Meier, G.G. & Haverson, P.J. 2011. Eradication of the House Crow from Socotra Island, Yemen. Island Invasives: Eradication and Management 361–363.
- Wilson, R.F., Sarim, D. & Rahman, S. (2015). Factors influencing the distribution of the invasive house crow (Corvus splendens) in rural and urban landscapes. Urban Ecosystems 18: 1389–1400.
Authors: Fortune Ravhuanzwo and Claude Moshobane