| Thick-billed raven | |
|---|---|
 | |
| InEthiopia | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Passeriformes |
| Family: | Corvidae |
| Genus: | Corvus |
| Species: | C. crassirostris |
| Binomial name | |
| Corvus crassirostris Rüppell, 1836 | |
 | |
Thethick-billed raven (Corvus crassirostris), acorvid from theHorn of Africa, shares with thecommon raven the distinction of being the largest bird in the corvid family. The thick-billed raven averages 64 cm (25 in) in length, with a range of 60 to 70 cm (24 to 28 in) 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 (i.e. those from theHimalayas andGreenland/Canadian Northwest Atlantic) 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 Australasiansuperb lyrebird, which is sometimes erroneously titled the largest passerine.[2][3][4][5]
It has a very largebill 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 8–9 cm (3.1–3.5 in) in length, is black with a white tip and has deep nasal grooves with only light nasalbristle covers.[6] 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.
Its range coversEritrea,Somalia andEthiopia; its habitat includesmountains and highplateaux between elevations of 1,500 to 3,400 metres. It is one of several avian species endemic to northeastern tropical Africa.[7]
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.[citation needed]
It nests intrees and oncliffs, apparently building a sticknest like the similar and much more widely distributed and studiedwhite-necked raven. It lays three to fiveeggs. In one case, thick-billed ravens were observed to vigorously displace predatoryVerreaux's eagle owls from their nest area.[8]
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 behaviour is rare in the wild, and is normally recorded only in captivity.[2]
.jpg)
.jpg)
.jpg)
.jpg)
.jpg)
.jpg)
_Corvus_crassirostris.png)
