402 OWLS 



have probably to do with an adaptive rather than an essential feature. 

 And it is noteworth}- that while some owls lay their eggs in the deserted 

 nests of other birds, a few are reported to build nests of twigs for 

 themselves in hawk-fashion. Like young falcons, newly hatched owls 

 are helpless and thickly covered with down, and require long attention 

 on the part of their parents. Again, although in some owls there is 

 no difference in this respect, in others the female exceeds her partner 

 in size, but not to the same extent as in the Accipitres. There is no 

 seasonal change in the colour of the plumage, and the young differ 

 but little from the adults. 



As already mentioned incidentally, the great majority of owls are 

 nocturnal or subnocturnal in their habits ; and all are carnivorous, feed- 

 ing for the most part on field-mice, shrew-mice, small birds, or reptiles, 

 although a few have taken to a diet of fish, while many of the smaller 

 kinds are content with large insects. A peculiarit)- of the group is 

 the habit of rejecting the indigestible portions of their food, which are 

 disgorged in the form of pellets ; large accumulations of such pellets 

 being often found beneath the roosting-places of these birds. 



From the foregoing remarks it will be apparent that many of the 

 points in which owls differ from the diurnal group of predaceous birds 

 are largeh' due to their nocturnal mode of life, coupled with their 

 habit of nesting in holes ; and it is probable that the forward direction 

 of their e}'es and the presence of the face-disk are attributable to the 

 same cause ; the latter peculiarities being cvidcntl}' well suited, in 

 correlation with the large size of the eyes themselves, for gathering up 

 every available ray of light. 



The barn-owl is the t)'pe not only of the genus Strix, but of the 

 family Strigid.e, which includes, in addition, a second genus from 

 Madagascar. The family is specially characterised by the presence of 

 only a single shallow notch on each side of the hind, or lower, border 

 of the breast-bone, and by the union of the latter with the merr}-- 

 thought or furcula, as well as by the circumstance that the second joint 

 of the middle toe considerably exceeds the basal one in length, while 

 the inner edge of the middle claw is serrated. 



Having no ear-tufts, the barn-owl differs from all other British 

 representatives of the order in that the aperture of the car is square 

 and protected by a large quadrangular flap of skin, and also b\- the 

 serrated inner edge of the claw of the middle toe. Except that the hen 

 is slightly the larger, the two sexes are alike externally ; there are, 

 however, two colour-phases common to both. In the t\pical phase 

 the face-disk is white with a brownish rim ; the upper-parts are bright 



