Carrion crow (Corvus corone)

KingdomAnimalia
PhylumChordata
ClassAves
OrderPasseriformes
FamilyCorvidae
GenusCorvus (1)
SizeWingspan: 84-100 cm (2)
Length: 44-51 cm (2)

The carrion crow is classified as Least Concern (LC) on the IUCN Red List (1). Receives general protection under the Wildlife and Countryside Act 1981 (3), but can be trapped, shot or their eggs and nests destroyed under the terms of General Licences issued by government (4). Included in the Birds of Conservation Concern Green List (low conservation concern) (5).

The carrion crow (Corvus corone) was, until recently, considered to be a race of the same species as the hooded crow (Corvus cornix), but it is now recognised as a separate species (4). It is the same size and shape as the hooded crow, but differs in that the plumage is entirely black, with a green and bluish-purplish gloss (2). The thick black bill has a curved tip (2). Vocalisations are croaky and harsh, and somewhat 'harder' than those of the hooded crow (2); the name 'crow' is imitative of their calls (6).

Occurs throughout Great Britain, south of the Great Glen in northern Scotland (4). There are two main carrion crow populations globally; one is distributed throughout most of Asia, the second occurs in western Europe (7). Where the distributions of carrion and hooded crows meet, there is a zone where interbreeding takes place and hybrids occur, which have intermediate plumage (7). In Great Britain, these hybrids occur in a band roughly between Aberdeen and Glasgow (7).

The carrion crow occupies an extremely broad range of habitats (7).

Carrion crows have a broad diet, including carcasses, eggs, insects, small vertebrates, molluscs, and even vegetables and grains in winter (7). They bury food for later consumption, and occasionally drop certain food items with hard shells, such as crabs and nuts, from a height in order to obtain the food inside (8).

This crow starts to breed at three years of age. Pairs, once formed, last for life. Courtship involves mutual preening, and a rapid head-bowing display by the male (8). Breeding pairs are very territorial, and create solitary nests in trees, bushes or on cliffs (8). The nest consists of thick branches and twigs intertwined with pegs, rags, paper, bones and other odd objects, held together with mud and dung and lined with wool, hair and grass (8). Four to five bluish-green, speckled eggs are laid in April, and are incubated by the female for up to 20 days. During this time, the male brings food to his mate on the nest. In the early part of their life, chicks are fed on regurgitated food by the female. Both parents then provision them with worms and maggots, progressing to various types of meat at a later stage (8). The young will have usually fledged after 35 days, but stay close to their parents for some time (8).

In winter large communal roosts of carrion crows can occur (8). This species displays behaviour known as 'anting'; individuals allow ants to crawl over their body, adopting unusual prone postures. They are also known to have a strange interest with fire, and have been seen carrying burning material to the nest, and then displaying unusual behaviour (8).

Carrion crows are perceived as a threat to livestock, as they are believed to kill and injure young lambs and trapped sheep (7). Although they do cause some problems of this nature, the perception is greater than the reality (7), and they have been persecuted as a result for many hundreds of years.

No conservation action has been targeted at the carrion crow.

For more information on the carrion crow and other bird species:

Information authenticated by the RSPB:
http://www.rspb.org.uk/

  1. IUCN Red List (April, 2011)
    http://www.iucnredlist.org/
  2. Mullarney, K., Svensson, L., Zetterstrom, D., & Grant, P.J. (1999) Collins Bird Guide. Harper Collins Publishers Ltd, London.
  3. Naturenet (July 2002):
    http://www.naturenet.net/law/wcagen.html
  4. RSPB (2003) Pers. comm.
  5. RSPB (2003) The population status of birds in the UK:
    http://www.rspb.org.uk/Images/5_20625.pdf
  6. Greenoak, F. (1979) All the birds of the air; the names, lore and literature of British birds. Book Club Associates, London.
  7. Lack, P. (1986) The Atlas of Wintering Birds in Britain and Ireland. T. & A. D. Poyser Ltd, Calton.
  8. Bruce Wilmore, S. (1977) Crows, jays, ravens and their relatives. David and Charles (Publishers) Ltd, London.