The rook (Corvus frugilegus) is a member of the family Corvidae in the passerine order of birds. It is found in the Palearctic, its range extending from Scandinavia and western Europe to eastern Siberia. It is a large, gregarious, black-feathered bird, distinguished from similar species by the whitish featherless area on the face. Rooks nest collectively in the tops of tall trees, often close to farms or villages, the groups of nests being known as rookeries. Rooks are mainly resident birds, but the northernmost populations may move southwards to avoid the harshest winter conditions. The birds form flocks in winter, often in the company of other Corvus species or jackdaws. They return to their rookeries and breeding takes place in spring. They forage on arable land and pasture, probing the ground with their strong bills and feeding largely on grubs and soil-based invertebrates, but also consuming cereals and other plant material. Historically, farmers have accused the birds of damaging their crops, and have made efforts to drive them away or kill them. Like other corvids, they are intelligent birds with complex behavioural traits and an ability to solve simple problems. Taxonomy and etymology The rook was given its binomial name by the Swedish naturalist Carl Linnaeus in 1758 in his Systema Naturae. The binomial is from Latin; Corvus means "raven", and frugilegus means for "fruit-gathering". It is derived from frux or frugis, meaning "fruit", and legere, meaning "to pick". The English-language common name rook is ultimately derived from the bird's harsh call. Two subspecies are recognised; the western rook (C. f. frugilegus) ranges from western Europe to southern Russia and extreme northwestern China, while the eastern rook (C. f. pastinator) ranges from central Siberia and northern Mongolia eastwards across the rest of Asia. Collective nouns for rooks include building, parliament, clamour and storytelling. Their colonial nesting behaviour gave rise to the term rookery. Description The rook is a fairly large bird, at adult weight, in length and wingspan. It has black feathers that often show a blue or bluish-purple sheen in bright sunlight. The feathers on the head, neck and shoulders are particularly dense and silky. The legs and feet are generally black, the bill grey-black and the iris dark brown. In adults, a bare area of whitish skin in front of the eye and around the base of the bill is distinctive, and enables the rook to be distinguished