Corvus

Corvus is a widely distributed genus of medium-sized to large birds in the family Corvidae. It includes species commonly known as crows, ravens and rooks. The species commonly encountered in Europe are the carrion crow, the hooded crow, the common raven and the rook; those discovered later were named "crow" or "raven" chiefly on the basis of their size, crows generally being smaller. The genus name is Latin for "crow".The 45 or so members of this genus occur on all temperate continents except South America, and several islands.