The coloration of the livery is dominated by shades of black, with some species having plumage with metallic iridescence and others that have white or gray areas on the neck or torso.

The members of the genus Corvus are believed to have evolved in Central Asia and radiated out from there into North America, Africa, Europe, and Australia.

[10] The type species is the common raven (Corvus corax);[11] others named by Linnaeus in the same work include the carrion crow (C. corone), hooded crow (C. cornix), rook (C. frugilegus), and two species which have since been moved to other genera, the western jackdaw (now Coloeus monedula) and the Eurasian magpie (now Pica pica).

Historical records suggest that the population of American crows found in North America has been growing steadily since the introduction of European colonization, and spread east to west with the opening of the frontier.

[12] Crows gather in large communal roosts numbering between 200 and tens of thousands of individuals during nonbreeding months, particularly in the winter.

In many species, the pattern and number of the numerous vocalizations have been observed to change in response to events in the surroundings (e.g. arrival or departure of crows).

Ravens have been mostly seen among travelling wolf packs rather than resting wolves, possibly due to the increased likelihood of food.

[29] One species, the New Caledonian crow, has also been intensively studied recently because of its ability to manufacture and use tools in the day-to-day search for food.

On 5 October 2007, researchers from the University of Oxford presented data acquired by mounting tiny video cameras on the tails of New Caledonian crows.

[35] Evidence also suggests they are one of the few nonhuman animals, along with insects like bees or ants, capable of displacement (communication about things that are not immediately present, spatially or temporally).

These results help to show how ravens prefer to form stable relationships with siblings and close social partners as opposed to strangers.

They eat almost any food, including other birds, fruits, nuts, mollusks, earthworms, seeds, frogs, eggs, nestlings, mice, and carrion.

[54] Crows are protected in the U.S. under the federal Migratory Bird Treaty Act of 1918, but because of their perceived destructive nature, control of the species is allowed in certain areas.

Before any measure is used to confine, trap, kill, poison, immobilize, or alter the habits of any wild bird species, a person must check local, state, and federal regulations pertaining to such actions.

[55] Liability and possible danger to persons and property limit the use of hunting or shooting as control methods in urban areas.

[58] Homeowners can reduce the presence of crows by keeping trash stored in containers, feeding pets indoors, and hanging tin pie-pans or reflective gazing globes around garden areas.

Crows were hunted for survival by Curonians, a Baltic tribe,[59] when common food was exhausted and the landscape changed so that farming was not as productive during the 18th and 19th centuries.

Fishermen supplemented their diet by gathering coastal bird eggs and preserving crow meat by salting and smoking it.

After the nonhunting policy was lifted by the Prussian government in 1721–1724 and alternative food supplies increased, the practice was forgotten.

It was a job for the elderly or young who were unable to go to sea to fish, and it was common to catch 150 to 200 birds during a hunting day.

[60] Rooks have been blamed for eating grain in the UK and brown-necked ravens for raiding date crops in desert countries.

[63][64] In Ancient Greece and Rome, several myths about crows and jackdaws included: In the Bible account at 1 Kings 17:6, ravens are credited with providing Elijah food.

In Hindu astrology, it is said that one who has the effect of Sani in their horoscope are angered easily, and may be unable to take control of their futures, but are extremely intelligent at the same time.

[75] Crows are also fed during the fifteen day period of Pitru Paksha, which occurs in the autumn season, as an offering and sacrifice to the ancestors.

During the time of Pitra Paksha, it is believed that the ancestors descend on Earth from pitra-loka, and are able to eat food offered to them by the means of a crow.

This can also occur during the time of Kumbha, many Hindus prepare entire vegetarian meals that are eaten solely by the crows and other birds.

[citation needed] In Norse mythology, Huginn and Muninn are a pair of common ravens that range the entire world, Midgard, bringing the god Odin information.

[80] In Welsh mythology, the god Brân the Blessed – whose name means "crow" or "raven"—is associated with corvids and death; tradition holds that Bran's severed head is buried under the Tower of London, facing France—a possible genesis for the practice of keeping ravens in the Tower, said to protect the fortunes of Britain.

In some Native American mythologies, especially those in the Pacific Northwest, the raven is seen as both the Creator of the World and, separately, a trickster god.

According to Landnámabók, a mythological account on the discovery of Iceland, Hrafna-Flóki is supposed to have used three ravens to scout for land around 860-870 CE when he came across the island.