[Illustration: THE TREE OWL (_Syrnium aluco_).] These birds inhabit Central Europe, and are likewise found in the northern parts of Asia and America; they are never seen in any large numbers, and are reckoned among the greatest rarities in our aviaries, owing to the difficulties attendant on their capture, for their retreats are usually in the deepest recesses of woods and forests, which they seldom quit. A hollow tree is the favourite resort of a pair of Hairy-footed Owls, and there they remain during the whole day, but at night fly away together in search of food. They appear carefully to avoid the light of the sun, and are extremely timorous. Should they be molested by the sportsman, they at once lie down close behind the branch in which they are perched, and thus effectually put themselves out of both sight and gunshot. Their voice somewhat resembles the syllables "Wi, wi, wi," and is not unlike the whimper of a child; this cry is heard principally in the evening and at early morning. The eggs, three or four in number, are deposited about April or May in a hollow tree, and are similar to those of the Stone Owl. Mice, insects, small birds, and bats constitute their principal food; the latter, according to our own observations, are caught on the wing. As in the case of the Uhu, all the small birds seem to delight in mobbing and harrying this dreaded foe, whenever they discover it sitting in the day-time perched and perfectly helpless. The young are destroyed in great numbers by the larger species of Owls and other enemies. A Hairy-footed Owl kept in Dr. Brehm's house soon became extremely tame, and though at first it invariably took refuge in the darkest corner of its dark cage, it soon lost this habit, and hopped about even during the day; it took its food from the hand of its master, and carried it to a quiet nook to be devoured, concealing the prize with its feathers whilst it ate. It seldom drank, but bathed almost daily when the weather was warm; if cold, it crouched upon the ground, drawing up its feet under its body. Its voice sounded occasionally somewhat like the low bark of a dog. [Illustration: THE BARN OWL (_Strix flammea_).] * * * * * The VEILED OWLS (_Strix_) constitute one of the most remarkable groups of this very important family. Their body is slender, the neck long, the head large and broad, the wings of great size, and the tail of medium length, the legs are high, the plumage silky and very varied in its coloration. The beak is elongate, straight at the base, hooked at its tip, and the under mandible slightly indented. The eye is small and more arched than that of other species; the ear appears unusually large, owing to the long feathers by which it is encircled, and which form a heart-shaped frill around the face, the tarsi are but slightly plumed, and are covered upon the lower portion with fine bristles; the toes are almost bare, the claws long, thin, and pointed.