1906 THE OWLS 



these birds in keeping in check the pestilential field vole, it is afforded by the flocks 

 of owls that collected from all sides to prey on the hosts of these rodents which 

 recently infested portions of Scotland. In all owls the indigestible remnants of 

 their food, such as bones, feathers, hair, scales, etc., are formed into pellets in the 

 stomach, and disgorged; such castings affording incontestible evidence of the nature 

 of the food of these birds. All owls are furnished with a syrinx, or organ of voice, 

 which most of them know only too well how to use; their cries taking the form 

 of hooting, howling, screeching, or a weird kind of laughter. It is from these 

 cries that the names of these birds are derived in many languages, as witness the 

 English owl, the German eule y the L,atin ulula, and the Hindustani ulu. 



BARN OWLS 

 Family STRIGID^ft 



Although one of the commonest and most familiar of all the group, the barn 

 owl (Strix flammed) is of special interest as constituting, together with a few 

 nearly-allied forms, a family apart from that which includes all the other repre- 

 sentatives of the order. This family (Strigidtz} is characterized by the breastbone, 

 or sternum, having its lower margin entire, and also by its keel being firmly united 

 with the furcula. Then, again, the third claw has its inner margin serrated, while 

 the second and third toes are of equal length. An additional peculiarity is to be 

 found in the presence of a small patch of stiff feathers between the adjacent portions 

 of the face discs. In the cannon bone the bridge over the hollow at the upper end 

 is absent. As a genus, the barn owls are characterized by the completeness of the 

 discs round the eyes, which are large, and narrow rapidly as they approach the 

 beak. The wings are long, and extend considerably beyond the tail; the beak is 

 straight at the base, and decurved only at the tip, and the aperture of the ear is 

 large, and furnished with a distinct lid. The head is devoid of tufts, and the rather 

 long legs are feathered down to the origin of the toes. 



The common barn owl has a wider distribution than any other member of the 

 order, being in fact almost cosmopolitan, although comparatively rare in the extreme 

 north, and unknown in New Zealand, parts of Oceania, Persia, Japan, and China. 

 With this extensive distribution, it would be only natural to expect great variation 

 in the color of the plumage; and, as a matter of fact, we find representatives of 

 this owl from widely distant regions so unlike one another that it is at first sight 

 difficult to believe that they belong to the same species, more especially as there 

 are also differences in point of size. In the ordinary British form, of which the 

 length averages fourteen inches, the face discs are white, with their margins defined 

 by the feathers being tipped with brown; the top of the head and neck are pale buff, 

 dotted with specks of black and white; on the back and w T ings a darker buff, 

 speckled with gray and irregularly mottled with black and white, obtains; the 

 tail feathers are pale buff above, marked with five transverse gray bands, and the 

 whole of the under parts are white. From this normal coloration there is every 



