CLASS AVES (BIRDS). 339 



is a mark of their success in life. Man himself has proba- 

 bly proved the worst enemy of the birds, indirectly as 

 well as directly. Much of their success is due to the 

 instincts of nesting and care of young. 



333. Relation to Man. Some birds, as the English 

 sparrow, eat chiefly grain, seeds, and fruits. Such are 

 sometimes something of a pest to man. Unquestionably, 

 however, the chief source of food of the small landbirds 

 is the great group of insects. The birds, more than any 

 other group of animals has kept down the insect popula- 

 tion. They might almost be considered as engines to 

 destroy insects. If all the birds were suddenly destroyed, 

 unquestionably many species of insects would increase 

 to the point where they would be a fearful pest to man- 

 kind, before a new balance in nature would be struck. 

 These facts are at the bottom of the agitation of recent 

 years that egg collecting and the slaughter of birds for 

 "sport" shall stop, 



Large numbers of weed seed are destroyed by birds. 

 An observer found 7,500 seeds of one common weed in 

 the stomach of one dove. Mice and other hurtful rodents 

 are captured by owls and other preying birds. The ducks 

 and geese and the orders to which the barn-yard fowl and 

 the pigeons belong are the only orders that are likely to 

 supply any large amount of human food. But, as in the 

 case of the fishes, these are destined to be reared with 

 much more care and success in the future than has yet 

 been true. They now, for the most part, receive little 

 of the attention of the farmer, and yet they furnish the 

 surest and most profitable returns that he gets. 



Of no less importance to man is the color and song and 

 poetry of the bird life. It has attracted thousands to 



