Pied crow

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Pied crow
Corvus albus -Etosha National Park, Namibia-8.jpg
In Etosha National Park, Namibia
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Corvidae
Genus: Corvus
Species:
C. albus
Binomial name
Corvus albus
Müller, 1776
Corvus albus updated map.jpg

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

Contents

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. The 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. [2]

Measurements

Identification

In southern Africa, its range overlaps with the white-necked raven. The pied crow is slightly 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. [3] It is larger than the black crow.

Voice

The voice is often described as a harsh ar-ar-ar-ar or karh-karh-karh. [2]

Taxonomy

The pied crow was first described in 1776 by Statius Muller. Its specific name is the Latin adjective albus, meaning "white".

The Maasai people call it ol-korrok from the sound of its call. It is considered annoying, but not a bird of ill omen. [4]

Distribution and habitat

This species, Africa's most widespread member of the genus Corvus, occurs from sub-Saharan Africa, specifically Nigeria, Ghana, Senegal, Sudan, Somalia, Eritrea, Zambia, Botswana, Mozambique and Zimbabwe, south to the Cape of Good Hope and on the large island of Madagascar, the Comoros Islands, Aldabra, Assumption Island, Cosmoledo, Astove Island, 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 the house crow (Corvus splendens) of Asia, and may be encountered far from human habitation in Eritrea. [2]

Pied Crow (Corvus albus) closeup from front.jpg

Behaviour

In flight Pied crow.jpg
In flight

Pied crows are generally encountered in pairs or small groups, although an abundant source of food may bring together large numbers of birds. The species behaves in a similar manner to the hooded and carrion crows. [2] 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, trees, etc., including injured wildlife 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 fruit. [2] It has been recorded killing and eating roosting fruit bats, and is frequently seen (sometimes in huge numbers) scavenging around slaughterhouses.

Digestion in the small intestine

The small intestines within the African pied crows include duodena, jejuna, and ilea, which are vital components for nutrient absorption, such as fats, proteins, and carbohydrates consumed by the crow.

Pancreatic ducts and two bile ducts make up the duodenum, so provide greater support for nutrient digestion. [5] 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. [6] To maintain their slender weight, these birds rely on this reduced digestive capacity to aid in food regulation to ensure they can fly swiftly. [7]

Pied crows obtain a characteristic looping and spiraling of their small intestines, which enhances their digestion and absorption of nutrients. [8] 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. [5]

Reproduction

Corvus albus - (MHNT) Corvus albus MHNT.ZOO.2010.11.170.5.jpg
Corvus albus - (MHNT)
Clamator glandarius in a clutch of Corvus albus - MHNT Clamator glandarius MHNT.ZOO.2010.11.152.15.jpg
Clamator glandarius in a clutch of Corvus albus - MHNT

The nest is usually built in tall, isolated trees, though sometimes smaller specimens are used, depending on availability. The cross supports of telephone poles are also frequently used, and both sexes build the nest. A clutch of three to six 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. [2]

See also

Related Research Articles

<span class="mw-page-title-main">Corvidae</span> Family of perching birds

Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, magpies, jackdaws, jays, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Currently, 135 species are included in this family. The genus Corvus containing 47 species makes up over a third of the entire family. Corvids (ravens) are the largest passerines.

<span class="mw-page-title-main">Carrion crow</span> Species of bird

The carrion crow is a passerine bird of the family Corvidae and the genus Corvus which is native to western Europe and the eastern Palearctic.

<span class="mw-page-title-main">Hooded crow</span> Species of bird

The hooded crow, also called the scald-crow or hoodie, is a Eurasian bird species in the genus Corvus. Widely distributed, it is found across Northern, Eastern, and Southeastern Europe, as well as parts of the Middle East. It is an ashy grey bird with black head, throat, wings, tail, and thigh feathers, as well as a black bill, eyes, and feet. Like other corvids, it is an omnivorous and opportunistic forager and feeder.

<span class="mw-page-title-main">Australian raven</span> Passerine bird native to Australia

The Australian raven is a passerine bird in the genus Corvus native to much of southern and northeastern Australia. Measuring 46–53 centimetres (18–21 in) in length, it has all-black plumage, beak and mouth, as well as strong grey-black legs and feet. The upperparts are glossy, with a purple, blue, or green sheen, and its black feathers have grey bases. The Australian raven is distinguished from the Australian crow species by its throat hackles, which are prominent in adult birds. Older adult individuals have white irises, younger adults have white irises with an inner blue rim, while younger birds have dark brown irises until fifteen months of age, and hazel irises with an inner blue rim around each pupil until age two years and ten months. Nicholas Aylward Vigors and Thomas Horsfield described the Australian raven in 1827, its species name (coronoides) highlighting its similarity with the carrion crow. Two subspecies are recognized, which differ slightly in calls and are quite divergent genetically.

<span class="mw-page-title-main">Torresian crow</span> Species of bird

The Torresian crow, also called the Australian crow or Papuan crow, is a passerine bird in the crow family native to the north and west of Australia and nearby islands in Indonesia and Papua New Guinea. The species has a black plumage, beak and mouth with white irises. The base of the feathers on the head and neck are white. The Torresian crow is slightly larger with a more robust bill than the morphologically similar little crow.

<span class="mw-page-title-main">Little raven</span> Species of bird

The little raven is a species of the family Corvidae that is native to southeastern Australia. An adult individual is about 48–50 cm (19–19.5 in) in length, with completely black plumage, beak, and legs; as with all Australian species of Corvus, the black feathers have a grey base, and the iris of the adult bird is white . Although the little raven was first named by Gregory Mathews in 1912, it was only in 1967 that there was consensus to separate it from the Australian raven as a distinct species.

<span class="mw-page-title-main">Thick-billed raven</span> Species of bird

The thick-billed raven, a corvid from the Horn of Africa, shares with the common raven the distinction of being the largest bird in the corvid family, and indeed the largest of the passerines. The thick-billed raven averages 64 cm (25 in) in length, with a range of 60 to 70 cm and weighs approximately 1.15 kg (2.5 lb) in females and 1.5 kg (3.3 lb) in males on average. Its size is about the same as the largest subspecies of common raven but some common raven subspecies are rather smaller and, going on average weights, the thick-billed raven is likely the heaviest extant passerine. The thick-billed raven is about 25% heavier on average than the Australasian superb lyrebird, which is sometimes erroneously titled the largest passerine.

<span class="mw-page-title-main">White-necked raven</span> Species of bird

The white-necked raven is a species of raven native to eastern and southern Africa. It is somewhat smaller than the common raven or its nearest relative, the thick-billed raven C. crassirostris.

<span class="mw-page-title-main">Daurian jackdaw</span> Species of bird of the genus Coloeus

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<span class="mw-page-title-main">Collared crow</span> Species of bird

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The fan-tailed raven is a passerine bird of the crow family native to Eastern Africa and the Arabian Peninsula.

<span class="mw-page-title-main">Brown-necked raven</span> Species of bird

The brown-necked raven is a larger bird than the carrion crow though not as large as the common raven. It has similar proportions to the common raven but the bill is not so large or deep and the wings tend to be a little more pointed in profile. The head and throat are a distinct brownish-black giving the bird its English name, while the rest of the plumage is black glossed with purple, blue or purplish-blue. Like the common raven, thick-billed raven and white-necked raven, it is one of the larger raven species. The feathers of this species often fade quite quickly to a brownish black and the bird can look distinctly brown by the time it moults. The feet, legs and bill are black. The dwarf raven was formerly considered a subspecies but this bird now appears to be closer to the pied crow than this species.

<span class="mw-page-title-main">Large-billed crow</span> Species of bird

The large-billed crow, formerly referred to widely as the jungle crow, is a widespread Asian species of crow. It is very adaptable and is able to survive on a wide range of food sources, making it capable of colonizing new areas, due to which it is often considered a nuisance, especially on islands. It has a large bill, which is the source of its scientific name macrorhynchos and it is sometimes known by the common name thick-billed crow. It can also be mistaken for a common raven. Johann Georg Wagler first described the species from a holotype obtained from Java in the year 1827. The eastern jungle crow and Indian jungle crow were once considered conspecific and together called the jungle crow.

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<span class="mw-page-title-main">Crow</span> Index of animals with the same common name

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<span class="mw-page-title-main">Chihuahuan raven</span> Species of bird

The Chihuahuan raven is a species of crow in the family Corvidae that is native to the United States and Mexico.

<span class="mw-page-title-main">Somali crow</span> Species of bird

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References

  1. BirdLife International (2017). "Corvus albus". IUCN Red List of Threatened Species . 2017: e.T22735894A118783820. doi: 10.2305/IUCN.UK.2017-3.RLTS.T22735894A118783820.en . Retrieved 12 November 2021.
  2. 1 2 3 4 5 6 Goodwin D. (1983). Crows of the World. Queensland University Press, St Lucia, Qld. ISBN 0-7022-1015-3. p. 132-4
  3. 1 2 3 4 Roberts' Birds of Southern Africa. The John Voelker Bird Book Fund. pp. 474–477. ISBN   0-620-17583-4.
  4. Galaty, John G. (1998). "The Maasai Ornithorium: Tropic Flights of Avian Imagination in Africa". Ethnology. 37 (3): 227–238. doi:10.2307/3774014. JSTOR   3774014.
  5. 1 2 Okpe et al., 2016
  6. Allen, 1968.
  7. Lavin et al.,2008
  8. Banks, 1993