The Carrion Crow is a member of the passerine order of birds and the crow family which is native to western Europe and eastern Asia.
The plumage of Carrion Crow is black with a green or purple sheen, much greener than the gloss of the Rook. The bill, legs and feet are also black. It can be distinguished from the Common Raven by its size (48-52 cm or 18 to 21 inches in length) and from the Hooded Crow by its black plumage, but there is frequent confusion between it and the Rook. The beak of the Crow is stouter and in consequence looks shorter, and whereas in the adult Rook the nostrils are bare, those of the Crow are covered at all ages with bristle-like feathers.
This species breeds in western and central Europe, with an allied form or race C. c. orientalis (50-56 cm or 19 to 22 inches in length) occurring in eastern Asia. The separation of these two populations is now believed to have taken place during the last ice age, with the closely allied Hooded Crow (now given species status) filling the gap between. Fertile hybrids occur along the boundary between these two forms indicating their close genetic relationship. This is an example of the parapatric speciation model described by Ernst Mayr. The range of this hybrid of these two species appears to be moving to the northwest.