Rook

Rook, common name for a bird of the crow family, the most abundant member of its genus in Europe. Both sexes have glossy black plumage and are about the same size as the carrion crow. Juveniles look much like other crows, but then lose the feathers at the base of the bill, where the naked grey-white skin of the adult identifies the bird as a rook. The rook feeds on insects and is helpful in destroying insect pests. It is gregarious and nests in large colonies called rookeries. (This term is now used for any such nesting assemblage, regardless of species.) The nests, built of twigs and earth, are strong enough to be used for many years. Three to five eggs, which are green with grey and broken markings, are laid in a clutch in the spring.

Scientific classification: The rook belongs to the family Corvidae of the order Passeriformes. It is classified as Corvus frugilegus.