The thick-billed raven (''Corvus crassirostris''), a

corvid Corvidae is a Cosmopolitan distribution, cosmopolitan family (biology), family of oscine passerine birds that contains the crows, ravens, rook (bird), rooks, jackdaws, jays, magpies, treepies, choughs, and nutcracker (bird), nutcrackers. In coll ...

from the

Horn of Africa The Horn of Africa (HoA), also known as the Somali Peninsula, is a large peninsula and geopolitical region in East Africa.Robert Stock, ''Africa South of the Sahara, Second Edition: A Geographical Interpretation'', (The Guilford Press; 2004), ...

, shares with the

common raven The common raven (''Corvus corax'') is a large all-black passerine bird. It is the most widely distributed of all corvids, found across the Northern Hemisphere. It is a raven known by many names at the subspecies level; there are at least e ...

the distinction of being the largest bird in the corvid family, and indeed the largest of the

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by t ...

s. The thick-billed raven averages in length, with a range of and weighs approximately in females and in males on average. Its size is about the same as the largest subspecies of common raven (i.e. those from the

Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

and

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

Canadian Northwest Atlantic Canadian Northwest Atlantic Command was the zone of operations during the Battle of the Atlantic that stretched from north of New York City to 47 degrees west. It was set up at the Atlantic Convoy Conference, held in Washington, DC from 1–12 ...

) 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 The superb lyrebird (''Menura novaehollandiae'') is an Australian songbird, one of two species from the family Menuridae. It is one of the world's largest songbirds, and is renowned for its elaborate tail and courtship displays, and its excell ...

, which is sometimes erroneously titled the largest passerine.Madge, S. (2010). ''Crows and jays''. A&C Black. It has a very large

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Plac ...

that is laterally compressed and is deeply curved in profile giving the bird a very distinctive appearance. This bill, the largest of any passerine at in length, is black with a white tip and has deep nasal grooves with only light nasal bristle covers. This raven has very short feathers on the head, throat and neck. The throat and upper breast have an oily brown gloss, while the rest of the bird is glossy black except for a distinctive white patch of feathers on the nape and onto the neck.

Distribution and habitat

Its range covers

Eritrea Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopia ...

Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...

and

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

; its habitat includes

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...

s and high

plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ha ...

between elevations of 1,500 to 3,400 metres. It is one of several avian species endemic to northeastern tropical Africa.

Behaviour

Neue Wirbelthiere zu der Fauna von Abyssinien gehörig (1835) Corvus crassirostris

Diet

The thick-billed raven is omnivorous, feeding on grubs, beetle larvae from animal dung, carrion, scraps of meat and human food. It has been seen taking standing wheat. When seeking food from dung, it has been seen using a distinct scything movement to scatter the dung and extract the grubs.

Nesting

It nests in

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s and on

cliff In geography and geology, a cliff is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on co ...

s, apparently building a stick

nest A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materia ...

like the similar and much more widely distributed and studied

white-necked raven The white-necked raven (''Corvus albicollis'') is somewhat smaller (50–54 cm in length) than the common raven or its nearest relative, the thick-billed raven ''C. crassirostris''. It is native to eastern and southern Africa. Descriptio ...

. It lays three to five

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s. In one case, thick-billed ravens were observed to vigorously displace predatory

Verreaux's eagle owl Verreaux's eagle-owl (''Bubo lacteus''), also commonly known as the milky eagle owl or giant eagle owl, is a member of the family Strigidae. This species is widespread in sub-Saharan Africa. A member of the genus ''Bubo'', it is the largest Afric ...

s from their nest area.de Castro, J. J., & de Castro, M. (2014). ''Verreaux's Eagle Owl Bubo lacteus attacked by Thick-billed Ravens Corvus crassirostris''. Scopus, 32(1), 51-52.

Voice

Its calls include a harsh nasal croak, a low wheezy croak, a "raven-raven", and sometimes a "dink, dink, dink" sound. Like many corvids, the thick-billed raven is capable of vocal mimicry; however, this behavior is rare in the wild, and is normally recorded only in captivity.

References

External links

Thick-billed Raven videos, photos & sounds
on the Macaulay Library {{Taxonbar, from=Q181561

thick-billed raven The thick-billed raven (''Corvus crassirostris''), 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 a ...

Birds of the Horn of Africa