6 BIRDS IN THEIR RELATIONS TO MAN. 



As to the relations between the birds themselves — especially 

 the few that prey upon their kindred — in general we are con- 

 tent to let Nature work out her balance of life in her own 



HEAD tiF SHRIKE. 



way. The chief exception lo this under our present condi- 

 tions would be in the notable case where short-sighted man 

 has interfered with Nature's balance by introducing the Eng- 

 lish sparrow, which, we regret to say, is becoming well estab- 

 lished in our town. And we have the same feeling with 

 regard to those parasitic and predaceous insects which birds 

 undoubtedly devour: we are quite sure that by so doing they 

 are helping to keep the balance of insect life where it will be 

 most effective for man's benefit. 



The birds are also to be credited with the destruction of 

 an enormous amount of weed-seed, a service which is little 

 appreciated by the general public. The estimate by Profes- 

 sor F. E. L. Beal, that the tree-sparrows alone will eat eight 

 hundred and seventy-five tons of weed-seed in Iowa in one 

 season, should help to a more general appreciation of this 

 phase of bird activity. 



There are various other benefits derived from birds which 

 are not illustrated in our local conditions. One such is the 



