The pied crow (Corvus albus) is a widely distributed African bird species in the crow genus of the family Corvidae.
Structurally, the pied crow is better thought of as a small crow-sized raven, especially as it can hybridise with the Somali crow (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.
Description
It is about the size of the European carrion crow or a little larger (46–50 cm in length), but has a proportionately larger 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. The tail, bill, and wings are black, too. Its eyes are dark brown. The white plumage of immature birds is often mixed with black. It resembles the white-necked and thick-billed ravens, but has a much smaller bill.
Measurements
- Length 46 – 52 cm
- Wing 328 to 388 mm (17 unsexed birds)
Distribution and habitat
This species, Africa's most widespread member of the genus Corvus, can be found in sub-Saharan Africa, specifically Nigeria, Ghana, Senegal, Sudan, Somalia, Eritrea, Zambia, Botswana, Mozambique and Zimbabwe, South Africa and on the large island of Madagascar, the Comoros Islands, Aldabra, Assumption Island, Cosmoledo, Astove Island, Zanzibar, Pemba, and Fernando Po. It does not occur in the equatorial rainforest region. It inhabits mainly open country with villages and towns nearby. This bird 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. The wall of the small intestine is lined with four main tunics - tunica mucosa, tunica submucosa, tunica musclaris, and tunica serosa. The primary purpose of the said tunics is to protect the inner environment of the small intestine against foreign invaders that could otherwise harm the crow.
Pied crows tend to operate with restricted digestive capacity despite being capable of consuming greater than half their body weight of food per day. To maintain their slender weight, these birds rely on this reduced digestive capacity to aid in food regulation to ensure they can fly swiftly.
Pied crows obtain a characteristic looping and spiraling of their small intestines, which enhances their digestion and absorption of nutrients. These birds also obtain restricted gut retention time for food, but to combat this, they also have increased mucosal surface area evident within their digestive tracts.