160 TEXT-BOOK OF ZOOLOGY 



may be aptly compared to a telescope, the bird at first descends in spiral 

 curves, but finally swoops down to the ground with rushing speed. It is 

 soon followed by its companions, to whom this downward rush is the signal 

 that food of some sort or other has been sighted. The loathsome feast 

 now begins. With a few thrusts of their powerful beaks the thick hide 

 of the carcase a dead horse or llama is speedily torn open. The birds 

 next thrust their long naked necks into the cavity of the animal's chest 

 or belly. (Of what advantage are a long and bare neck to the birds ?) 

 The entrails and large pieces of the flesh are torn away with the hooked 

 end of the upper beak, or cut away in shear-like fashion by the sharp edges 

 of the bill The separate portions are swallowed in huge lumps, bones 

 and all. The pharynx and oesophagus of these animals are accordingly 

 very wide, and the gastric juices very acid. Each of the birds devours 

 as much as it possibly can on the spot, since (owing to the probable 

 arrival of smaller carrion-feeders, and also rapidly ensuing putrefaction) 

 there would be none of the meal left on the morrow, and it may be 

 some days before another equally rich feast is provided. The crop and 

 proventriculus are, therefore, also of unusually large size, the former, 

 when filled, protruding from the neck like a sack. Having satiated their 

 appetites, the birds, scarcely able to move, rest for a time. They then 

 fly to the water, in order to drink and clean their blood-smeared feathers. 

 Vultures are only found in warm or hot regions^ where carrion is 

 always abundant. Those species which frequent towns and villages, by 

 consuming, before they putrefy, dead animal carcases and all sorts of 

 offal thrown into the streets, are highly useful to the inhabitants, acting, 

 in fact, as public scavengers or sanitary police. (Compare the condor 

 with the hyaena.) 



Family 3 : (Owls Strigidae). 



The Barn-Owl (Strix flammed). 

 (Length about 14 inches.) 



A. Its Food and Importance to Man. 



Like the buzzard, the barn-owl feeds only on live animals. Though 

 among these must be classed the larger insects, shrew-mice, moles, and 

 occasionally singing birds, its food consists chiefly of mice; so that it 

 has been called, not without reason, " a flying cat." (Show also how it 

 deserves this title in regard to its structure and manner of pursuing the 

 prey according to the headings as given below.) The bird, therefore, is 

 a valuable helpmate to man, which ought to be protected and preserved. 



