157223 Rook - Corvus frugilegus. L 43-48cm. Familiar farmland bird. Feeds in large flocks (mainly on soil invertebrates) and occupies noisy colonial tree nest sites. Sexes are similar. Adult has black plumage with reddish-purple sheen. Bill is long, narrow and rather pointed; note bare patch of whitish skin at base. Juvenile is similar but skin at base of bill is feathered. Voice Utters a grating craah-craah-craahâ€¦ call. Status Locally common resident, found mainly on farmland and grassland. Builds large twig nests in clumps of tall trees.