Pied crow

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The pied crow (Corvus albus) is a widely distributed African bird species in the crow genus.

Structurally, the pied crow is better thought of as a small crow-sized Raven (except the lack of throat hackles, fan-shaped tail and other more crow-like traits), especially as it can hybridise with the Somali crow (sometimes called the Dwarf Raven) where their ranges meet in the Horn of Africa. Its behaviour, though, is more typical of the Eurasian carrion crows, and it may be a modern link (along with the Somali crow) between the Eurasian crows and the common raven.

Video Pied crow

Description

It is approximately the size of the European carrion crow (46-52 cm in length) but has a longer bill, slightly longer tail and wings, and longer legs. As its name suggests, its glossy black head and neck are interrupted by a large area of white feathering from the shoulders down to the lower breast but the tail, bill and wings are black. The eyes of a fully matured bird are dark brown. The white plumage of immature birds is often mixed with black. It resembles the White-necked and thick-billed ravens but is much smaller, less stocky and has a smaller bill.

Measurements

• Length 46 - 52 cm
• Wingspan 85 to 98   centimetres (17 unsexed birds)
• Weight 520g

Identification

In southern Africa the range overlaps with the white-necked raven. The pied crow is smaller and has a white chest and belly with a black, more delicate beak compared to the black chest and belly of the larger white-necked raven which also has a white tipped and weightier beak.

Vocalisation

The voice is described as a harsh "ar-ar-ar-ar" or "karh-karh-karh" and lacks the whispering note of the White-necked raven.

Maps Pied crow

Taxonomy

The pied crow was first described in 1776 by Statius Muller. Its specific name is the Latin adjective albus, meaning "white". Recent findings indicate that based on mitochondrial DNA, common ravens (C. corax) from the north of the United States are more closely related to those in Europe and Asia than to those in the California clade, and that common ravens in the California clade (C. corax sinuatus) are more closely related to the Chihuahuan raven (C. cryptoleucus) than to those in the Holarctic clade. while ravens in the Holarctic clade are more closely related to the pied crow (C. albus) than they are to the California clade. Thus, the common raven species as traditionally delimited is considered to be paraphyletic.

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Distribution and habitat

This species, Africa's most widespread member of the genus Corvus, occurs from Sub-Saharan Africa, specifically Senegal, Sudan, Somalia and Eritrea down to the Cape of Good Hope and on the large island of Madagascar, the Comoros islands, Aldabra group islands, Zanzibar, Pemba and Fernando Po. Although the species is still a vagrant north of the Sahara, a breeding case and a number of long-staying birds were observed during the last few years in Morocco. It inhabits mainly open country with villages and towns nearby. It does not occur in the equatorial rainforest region. It is rarely seen very far from human habitation, though it is not as tied to the urban way of life as the house crow (Corvus splendens) of Asia, and may be encountered far from human habitation in Eritrea.

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Behaviour

Pied crows are generally encountered in pairs or small groups, although an abundant source of food may bring large numbers of birds. The species behaves in a similar manner to the hooded and carrion crows. In Dakar, birds have been observed mobbing passing ospreys and snake eagles but avoiding black kites.

Diet

All of its food is obtained from the ground such as insects and other small invertebrates, small reptiles, small mammals, young birds and eggs, grain, peanuts, carrion and any scraps of human food and sometimes fruit and even mushrooms. It has been recorded killing and eating roosting bats and is frequently seen scavenging around slaughterhouses in large numbers.

Reproduction

The nest is usually built in tall, isolated trees, though sometimes smaller ones are used, depending on availability. The cross supports of telephone poles are also frequently used, and both sexes build the nest. A clutch of 3-6 eggs is laid from September to November (depending on latitude) and are pale green spotted with various shades of brown. The eggs are normally covered when the incubating female leaves the nest. Incubation is 18-19 days and the young are usually fledged by around 45 days. Both sexes rear the young.

src: www.warrenphotographic.co.uk

References

Cited text

• Goodwin D. (1983). Crows of the World. Queensland University Press, St Lucia, Qld. ISBN 0-7022-1015-3. 

src: www.hbw.com

External links

• Pied Crow - Species text in The Atlas of Southern African Birds.
• Pied Crow videos, photos & sounds on the Internet Bird Collection
• How many tortoises do a pair of Pied Crows Corvus alba need to kill to feed their chicks? - Paper in ejournal Ornithological Observations

Source of article : Wikipedia