Rook (corvus frugilegus, Linn.), a bird of the crow family, about the size, form, and color of the common crow, from which it differs principally in having the base of the bill covered with a rough scabrous skin, whitish in old birds. It is about 20 in. long and 40 in. in alar extent, the bill 2 1/3 in.; the female is a little smaller; the color is black, with purple, greenish, and bluish reflections, the feathers of the neck blended, and on the fore part of the head abraded; the head is entirely feathered in the young; albinos sometimes occur, and the bill is often variously distorted. It is found over most of Europe, and abundantly in many parts of Great Britain. Rooks live in society all the year round, building their nests, seeking food, and roosting in flocks; their resorts, called rookeries, are often very extensive, one near Edinburgh in 1847 containing 2,660 nests and about 30,000 inhabitants of all ages. The nests are made on tall trees, often in the midst of populous towns, and the same are used year after year; they are fond of the groves of old family mansions, where they are protected.
Rook (Corvus frugilegus).
They are very early risers, going in search of worms in the fields or of garbage in the streets; they sometimes visit the beaches and flats in search of shellfish and crustaceans; they eat also grain, seeds, insects, nuts, and lizards, but rarely if ever carrion; they plunder the grain fields only when forced by hunger; they feed with birds of various families without quarrelling. They prefer open fields, placing a sentinel, and flying off at his alarm note with great noise; the flight is generally by slow and regular flappings, without undulations; they often go many miles in search of food, and if they return in the forenoon or early afternoon, a storm within 24 hours may be confidently expected. They begin to repair their nests early in spring, and lay four or five eggs, light greenish blue, spotted and clouded with grayish brown and light purplish gray; the young are hatched about' the middle of April, and leave the nest by May 20; great numbers of the newly fledged birds are annually shot to be eaten.
Rooks, a N. W. county of Kansas, intersected by the S. fork of Solomon river; area, 900 sq. m. It is not included in the census of 1870. The surface is gently rolling, and consists chiefly of prairies.