Rooks are highly social and gregarious, often seen in flocks. They are monogamous, with pairs forming lifelong bonds and staying together within the flock. These birds are diurnal, foraging on the ground during the day and roosting communally at night. They exhibit complex social behaviors and are known for their intelligence and problem-solving abilities.
The rook's call is a distinctive caw or kaah, variable in pitch and used in different contexts. It is less raucous than that of the carrion crow and is often heard in flight or while perched, where the bird may fan its tail and bow with each call.
Rooks nest colonially in rookeries located at the tops of tall trees. Both sexes contribute to nest-building, which is a cup-shaped structure made of sticks and lined with softer materials. The breeding season begins in spring, with egg-laying occurring by the end of March or early April in Britain, and possibly later in eastern Europe and Russia. The clutch size ranges from three to five eggs, which are incubated primarily by the female.
