The Mouse Buzzards are met with throughout a large part of Europe and Central Asia, appearing in the southern portions of our continent during the winter, and living solitarily in the vicinity of lofty mountains during the summer months. They are rarely seen in Northern Africa, or in the lower parts of India, but are common in certain districts of the Himalayas. In some of the warm countries of Europe they remain throughout the entire year; in such as are more northern, they arrive about March or April, and leave again in September. When about to migrate, these birds congregate in parties of from twenty to a hundred, and as the flocks usually proceed in the same course when quitting us, without actually assembling in large hosts, they often fly so as to spread their numbers over a square mile of country. At such times their flight is slow, and varied by the performance of many elegant evolutions, sweeping about in circles for half-an-hour at a time; and, as they return northwards, they often linger for whole days upon spots likely to afford them a plentiful supply of food. When about to settle, they generally select such localities as are well covered with trees, and in the vicinity of fields or pasture lands, these situations being rich in such game as they prefer; they are, however, found in large forests, and sometimes ascend to a great height in mountain ranges. [Illustration: THE COMMON OR MOUSE BUZZARD (_Buteo vulgaris_).] The movements of this Buzzard are characterised by a slowness and clumsiness that render it almost unmistakable, either as it soars slowly aloft, or sits, with body huddled together and ruffled plumage, upon the branch of a tree, from whence it watches with keen eyes, for the appearance of its prey. During the breeding season and early spring, however, these birds exhibit an activity for which we are quite unprepared, and soar to prodigious heights, displaying their skill in a variety of aërial manœuvres, apparently for the amusement of their mates. The voice of the Common Buzzard very closely resembles the mewing of a cat; its sight is excellent, its hearing delicate, and the other senses very well developed; its disposition is intelligent, keen, and sly. The eyrie is built, or an old one repaired, about May. This structure is placed upon a tree, and carefully formed of branches, such as are thickest being placed beneath the others; the interior is lined with very fine twigs, moss, hair, and other soft materials. The nest is about two feet in diameter. The brood consists of three or four greenish white eggs, spotted with light brown; the female alone sits, but at a later period both parents co-operate in tending the little family. This species occasionally takes possession of the nests of Crows or Ravens, instead of building on its own account.