This section is from the book "The Balance Of Nature And Modern Conditions Of Cultivation", by George Abbey. Also available from Amazon: The Balance Of Nature And Modern Conditions Of Cultivation.
The Barn Owl (Strix flammed), Fig. 23, is included in the family Strigidae, which in itself represents the nocturnal section of the order of Raptores or birds of prey. Its length is about 14 in., with very long wings reaching below the tail. The legs are long and thin, covered with downy feathers and with long claws; there are no tufts on the head, which is light buff in colour. The underpart of the body is white, and of the back buff, with bars and spots of blackish grey. The inside of the wings is white, the back and exterior of the wings vary somewhat in colour in different specimens. The nest is of the most rudimentary description and made in hollow trees, holes in rocks, ruins or old buildings, barns and church steeples. The eggs are pure white and about 1¼ in. in length and laid towards the end of April in number from three to six. Sometimes eggs are laid after the first brood of owlets has come forth and are hatched by the warmth of these young, so that owlets in various stages of growth may be found in the same nest.
Fig. 23. - The White or Barn Owl with Rat (lower figure), and Nightjar with Moth (upper figure).
The barn owl is found in all parts of the British Islands, though it is somewhat rare in the northern parts of Scotland, and frequents barns, pigeon-cots, stackyards, ruins, and hollow trees, the two latter being its chief haunts, and from its dwelling and nesting places scours the surrounding districts of field mice and rats, particularly young rats, its mousing proclivities being very pronounced, four species of mice having been found at the same time in one nest: the common house mouse, harvest mouse, long-tailed field mouse, and the short-tailed grass mouse (vole). It has been noted that forty mice have been brought to the nest of the barn owl in one hour. Mice and voles, with rats, varied with cockchafers, larger moths and other injurious insects form the chief dietary of the barn or white owl.