Rook Corvus frugilegus

The Rook can be distinguished from the Carrion Crow by its large, light grey beak and barer face; it is also not as sleek, often with shaggy feathers on its belly giving it an angular shape.
Typical bare grey beak and shaggy, angular shape. It is gregarious, found in flocks and roosting in rookeries of many nests in neighbouring trees.
Rook collecting acorn
Rook with acorn
Rook burrying acorn
Its corvid relative the Jay is well known for burying acorns for winter (and propagating oak trees). Here a Rook is doing the same, collecting acorns from beneath a tree and burying them in a field.
Rook with young crows
Adult Rook (left) with bare grey beak and untidy, angular appearance and two young Rooks which look like Crows with sleeker shape and feathered top of beak (which they lose later)
Young crows begging rook for food Two young Rooks (like Crows) begging parent for food
Rook Icy morning
Rook Rook gathering nesting material
Rook with Jackdaws Rook size comparison with two Jackdaws: bigger bird and beak but smaller head
Rookery A rookery is a colony of multiple nests
Rook Some have a bluish tinge. This one has some brown feathers.