White and black crow



About

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.

Descriptionedit
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.2
Measurementsedit
Length 46 – 52 cm 3
Wingspan 85 to 98   centimetres (17 unsexed birds)3
Weight 520g 3
Identificationedit
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.4
Vocalisationedit
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.5
Taxonomyedit
The pied crow was first described in 1776 by Statius Muller. Its specific name is the Latin adjective albus, meaning "white".
Distribution and habitatedit
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. 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 thehouse crow (Corvus splendens) of Asia, and may be encountered far from human habitation in Eritrea.2

Behaviouredit

In flight
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.6 In Dakar, birds have been observed mobbing passingospreys and snake eagles but avoiding black kites.
Dietedit
All of its food is obtained from the ground such as insects and other small invertebrates, small reptiles, small mammals, young birds andeggs, grain, peanuts, carrion and any scraps of human food and sometimes fruit and even mushrooms.7 It has been recorded killing and eating roosting bats and is frequently seen scavenging around slaughterhouses in large numbers.
Reproductionedit
The nest is usually built in tall, isolated trees, though sometimes smaller ones are used, depending on availability. The cross supports oftelephone 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.6


Share on Google Plus

About Unknown

0 comments:

Post a Comment