The Columbia Encyclopedia, Sixth Edition. 2001-07.
rook
term used for a common Eurasian bird (genus Corvus) of the family Corvidae (Crow family), smaller than the American crow. The jackdaw is a European species of the genus. Rooks nest in large colonies, whence the term rookery. They are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Passeriformes, family Corvidae.