Size: The rook is a fairly large bird, at 280 to 340 g adult weight, 44 to 46 cm in length and 81 to 99 cm wingspan.

Habitat: Rooks choose open agricultural areas with pasture or arable land, as long as there are suitable tall trees for breeding. They generally avoid forests, swamps, marshes, heaths and moorland. Rooks are often associated with human settlements, nesting near farms, villages and open towns, but not in large, heavily built-up areas.

Behaviour: Rooks are highly gregarious birds and are generally seen in flocks of various sizes. Males and females pair-bond for life and pairs stay together within flocks. Nesting in a rookery is always colonial, usually in the very tops of large trees. Female usually lays three to five eggs. About 60% of the diet is vegetable matter and the rest is of animal origin. Vegetable foods include cereals, potatoes, roots, fruit, acorns, berries and seeds while the animal part is predominantly earthworms and insect larvae. It also eats beetles, spiders, millipedes, slugs, snails, small mammals, small birds, their eggs and young, and occasionally carrion. In urban sites, human food scraps are taken from rubbish dumps and streets, usually in the early hours or at dusk when it is relatively quiet. In Latvia, there are 7,000-9,000 couples.

Interesting facts: Large groups of rooks (in breeding colonies or night roost sites) can contribute to changes in soil properties. The amount of orthogenic material in these soils is very high. You can distinguish a young rook from an old one by the colour of the base of its beak. Young rooks have characteristic feather tufts and a dark base of the bill, whereas old rooks have a light grey base.

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