Common Raven

Description:

A mature Common Raven ranges between 56 and 78 cm (22 to 30 inches) in length, with a wingspan of 100 to 150 cm (40 to 59 in).[27][28][29] Recorded weights range from 0.69 to 2 kg (1.5 to 4.4 lb),[30][31] thus making the Common Raven one of the heaviest passerines. Birds from colder regions such as the Himalayas and Greenland are generally larger with slightly larger bills, while those from warmer regions are smaller with proportionally smaller bills.[32] The bill is large and slightly curved, with a culmen length of 5.7 to 8.5 cm (2.2 to 3.3 in), easily one of the largest bills amongst passerines (perhaps only the Thick-billed Raven has a noticeably larger bill). It has a longish, strongly graduated tail, at 20 to 26.3 cm (7.9 to 10.4 in), and mostly black iridescent plumage, and a dark brown iris. The throat feathers are elongated and pointed and the bases of the neck feathers are pale brownish-grey. The legs and feet are good-sized, with a tarsus length of 6 to 7.2 cm (2.4 to 2.8 in).[33][34] Juvenile plumage is similar but duller with a blue-grey iris.[35] Apart from its greater size, the Common Raven differs from its cousins, the crows, by having a larger and heavier black beak, shaggy feathers around the throat and above the beak, and a wedge-shaped tail.[36] The species has a distinctive, deep, resonant prruk-prruk-prruk call, which to experienced listeners is unlike that of any other corvid. Its very wide and complex vocabulary includes a high, knocking toc-toc-toc, a dry, grating kraa, a low guttural rattle and some calls of an almost musical nature.[37] In flight the feathers produce a creaking sound that has been likened to the rustle of silk.[38] Common Ravens can be very long-lived, especially in captive or protected conditions; individuals at the Tower of London have lived for more than 40 years.[30] Lifespans in the wild are considerably shorter at typically 10 to 15 years. The longest known lifespan of a banded wild Common Raven was 23 years, 3 months.[39] Although ravens are almost always black, there do exist exceptionally rare white ravens.

Habitat:

Common Ravens can thrive in varied climates; indeed this species has the largest range of any member of the genus,[41][42] and one of the largest of any passerine.[43] They range throughout the Holarctic from Arctic and temperate habitats in North America and Eurasia to the deserts of North Africa, and to islands in the Pacific Ocean. In the British Isles, they are more common in Scotland, Wales, northern England and the west of Ireland.[36] In Tibet, they have been recorded at altitudes up to 5,000 m (16,400 ft), and as high as 6,350 m (20,600 ft) on Mount Everest.[42][44] The population sometimes known as the Punjab Raven — described as Corvus corax laurencei (also spelt lawrencii or laurencii) by Allan Octavian Hume but more often considered synonymous with subcorax[19] — is restricted to the Sindh district of Pakistan and adjoining regions of northwestern India.[38][45] Except in Arctic habitats,[46] they are generally resident within their range for the whole year. Young birds may disperse locally.[47] In the Faroe Islands a now extinct colour-morph of this species existed, known as the Pied Raven.[48] Most Common Ravens prefer wooded areas, with large expanses of open land nearby, or coastal regions for their nesting sites and feeding grounds. In some areas of dense human population, such as California in the United States, they take advantage of a plentiful food supply and have seen a surge in their numbers.