INTRODUCTION TO BIRDS. 259 



The terrestrial scavengers are the vultures, the 

 ravens, and the buzzards ; while along our shores are the 

 scavenger cormorants, herons, and gulls, though gulls 

 usually work farther out to sea than do the other birds 

 mentioned. 



Birds are the best friends the farmer has, not except- 

 ing our Secretaries of Agriculture, state and national. 

 Even the corn-eating crow that we hear so much about 

 in the spring has been eating mice and grubs and scraps 

 through the winter; while in the grasshopper season he 

 probably eats more grasshoppers than corn grains, day 

 for day; and grasshoppers increase much faster than crows. 

 It is not to be denied that crows do some damage to 

 sprouting grain ; but there is hardly any animal that is at 

 all times beneficial. How about ourselves, for instance? 



In a recent government report, a yellow-billed cuckoo, 

 killed at six in the morning, had in its crop the partially- 

 digested remains of forty-three tent caterpillars! How 

 many more it would have eaten before nightfall is- a 

 question. Birds digest their food very rapidly, so that 

 it is difficult to make estimates covering much time, and 

 the cuckoo belongs well up in the scale of bird life, where 

 all the vital processes are rapid. 



Besides furnishing "bread and butter" for scores, of 

 birds, insects are eaten by many of the other vertebrates. 

 Lizards, toads, frogs, and prairie squirrels catch insects 

 as long as the insects are with us; that is, until the ap- 

 proach of winter leads to the disappearance of their 

 natural food, when the conditions lead up to the hiber- 

 nation of many of these animals. The mole, which has a 

 reputation for being such a pest, is only trying to get 

 the white grubs and the caterpillars that have dug under 

 the ground surface to winter over. Of course, as the 



