Ravens and crows together form the genus Corvus in the family of ravens. The larger representatives are called "ravens", the smaller ones "crows". However, this is not a taxonomic classification. The genus comprises 42 species that are distributed almost worldwide and are only absent in South America. In Europe, the Common Raven, the Carrion Crow and the Little Raven can be found. As a naturalised neozoon, the House Crow has also been breeding in the Netherlands since the late 1990s.