Corvidae

Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In common English, they are known as the crow family, or, more technically, corvids. Over 120 species are described. The genus Corvus, including the jackdaws, crows, and ravens, makes up over a third of the entire family.

They are considered the most intelligent of the birds, and among the most intelligent of all animals, having demonstrated self-awareness in mirror tests (European magpies) and tool-making ability (crows, rooks)—skills until recently regarded as solely the province of humans and a few other higher mammals. Their total brain-to-body mass ratio is equal to that of great apes and cetaceans, and only slightly lower than in humans.

They are medium to large in size, with strong feet and bills, rictal bristles, and a single moult each year (most passerines moult twice). Corvids are found worldwide except for the tip of South America and the polar ice caps. The majority of the species are found in tropical South and Central America, southern Asia and Eurasia, with fewer than 10 species each in Africa and Australasia. The genus Corvus has re-entered Australia in relatively recent geological prehistory, with five species and one subspecies there.