310 ZOOLOGY. 



loose ])lumage is also quite characteristic, but is not peculiar, being occa- 

 sionally met with in the Caprimulgidcs (night-hawks). 



The brain is more voluminous than in other rapacious birds, and is 

 piotected by a remarkably thick, cellular cranium, which contributes to the 

 great size of the head, as apparent in the living bird. The organ of 

 hearing is very large and possesses much quickness and delicacy, and a 

 ])eculiar formation of the eye gives the owls a power of sight of the most 

 exquisite character. It is so constructed that the small amount of light at 

 twilight, or even in the night, is sufficient to produce perfect vision, though 

 the full daylight is too strong and dazzling for most of the species. 



The flight of the owls is less graceful and less capable of being long 

 continued than that of the preceding families. Tt is produced by repeated 

 flappings and has the advantage of being entirely without noise, owing to 

 the peculiar general structure of the wings, and a fine hair-like web on 

 the outer edge of the first quill. They are thus enabled to steal upon 

 their prey unawares and under cover of the darkness of night. 



Their plumage is almost invariably of dull and uniform colors, and is in 

 a great measure free from the diversity characteristic of age and sex in the 

 FalconidcB. Being nocturnal strictly, or active only in the twilight of the 

 evening or the morning, is generally characteristic of this class ; a few species, 

 however, are diurnal, and pursue their prey or attend to the wants of their 

 young in the full glare of daylight. Of these the great snowy owl {Nyctea 

 vivea) and the hawk owl (Surnia ulula), both found in the northern parts 

 of America, are examples. These are exceptions only, much the greater 

 mnnber of species being of the former character. 



The owls rarely devour any animals which have not recently suffered 

 death, though they are not always contented with being themselves the 

 instruments of destruction ; some species instinctively follow the hunter in 

 the northern countries, and pick up with eagerness grouse and other birds 

 recently killed by his gun. Their period of activity being in the night, 

 their repose is necessarily during the day, and if then disturbed most of the 

 species make gestures of a very ludicrous character, which seem chiefly 

 intended, however, to enable them to get a fair view of the intruder. 

 Some species fly off immediately upon perceiving that they are discovered. 



Some owls tear their food like the falcons, but the greater number 

 swallow small quadrupeds, birds, and insects entire, subsequently ejecting 

 from the mouth the hair, bones, and other indigestible matter rolled into 

 pellets by a peculiar action of the stomach. Their food is entirely animal, 

 and embraces every living thing which can be conquered by force or 

 stealth. 



The nesting-places of the owls are usually in hollow trees, fissures, or 

 caverns in rocks, dilapidated buildings, or similar places. They also 

 frequent such localities habitually during the day, or sometimes the 

 protection of a pine tree serves them when belated in the morning. This 

 peculiar family has been regarded with feelings nearly akin to superstition 

 from the earliest ages. The grotesque and oddly-shaped forms of most of 

 the species, their preference for the darkness of night or the gloomiest 

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