4*8 ZOOLOGY. 



vultures and their allies are scavengers and are thus a distinct 

 advantage to man. The remainder prey upon living animals, 

 chiefly vertebrates (Figs. 217-219). 



FIG. 219. 



FIG. 219. Skull of Owl (Syrnium nebulosum). After Shufeldt, photographed from 

 specimens. Upper figure bisected, showing brain-case; the lower from a dorsal 

 aspect. 



Questions on the figure. Is the owl a bird of prey? What is the 

 position of the eyes in relation to the skull? Of the nares? Compare 

 these figures with the head of the owl (Fig. 217), and with the skulls 

 in Fig. 216. 



The owls have interesting habits in that they are nocturnal 

 flyers, and during the day retire to dark places, where they 

 sit quietly. They thus reverse the habits of the majority of ver- 

 tebrates in the use of day and night. While there are many 

 nocturnal vertebrates, there are few so helpless in the light as 

 the owls. Their prey, in many instances, are nocturnal animals. 



