This building is the result of an attempt to solve an old problem in a new way—the care of large migratory water birds in the most uneven winter climate on earth. In comparison with the care in winter of flamingoes, large herons, egrets, ibises, and the like, the housing of perching birds, birds of prey and the parrots, presents few difficulties. But the wealth of fine water birds in North America alone, and the interest attaching to them, seem to justify the labor and expense that have been involved in this building and its appointments. Practically all of the birds to be seen in this building in winter are mentioned elsewhere in this volume. THE OWL CAGES.—After the completion of the Eagle and Vulture Aviary, the ten large cages on the exterior of the Aquatic-Bird House, which have been occupied temporarily by the birds of prey, will be used for the owl collection. The Giant Eagle Owl, (_Bubo bubo_), is a true giant among the owls. It is found throughout continental Europe, keeping mostly to the deep forests, and feeding on grouse, rabbits, etc. It is unusually long-lived in captivity, and breeds freely. The Milky Eagle Owl, (_Bubo lacteus_), has the same general characters as its congener, but its feathers are of a beautiful, soft gray. It is very rare in collections. The Great Horned Owl, (_Bubo virginianus_).—These nocturnal birds of prey inhabit heavily wooded regions, feeding on mice, and poultry when it is obtainable. The bright yellow iris, the conspicuous feather horns, and the apparently pivoted neck are curious features of these birds. Their reputation for wisdom is founded only on their external appearance, for in reality they are rather dull birds. The Snowy Owl, (_Nyctea nyctea_), of the Arctic regions, migrating in winter to the northern United States, sometimes remains for several seasons in succession so far north that no specimens are obtainable. During 1899, 1900, and the first half of 1901, not one specimen could be procured, but in the late autumn of 1901 a southward migration began. On June 1, 1911, the Park exhibited six fine specimens, one of which was almost pure white. During the three hottest months of summer, these birds would suffer considerably, so during this period they are confined in a cool, dark cellar, thus keeping in perfect health and comfort throughout the year. [Illustration: GREAT HORNED OWL.] [Illustration: SPECTACLED OWL.] The Screech Owl, (_Otus asio_).—This little horned owl is our commonest species, and frequents the neighborhood of dwellings and orchards. Being nocturnal it is more common than is generally supposed, and its curious cry, which is not a screech, but a musical, quavering series of notes, is the cause most frequently leading to its discovery. Its two phases of plumage, red and gray, occur independently of sex, age or season. Its food consists of mice and insects.