Useful Birds and their protection. 



Introductory. 



THE UTILITY OF BIRDS IN NATURE. 



There is no subject in the tielcl of natural science that is 

 of greater interest than the important position that the living 

 bird occupies in the great plan of organic nature. 



The food relations of birds are so complicated and have 

 such a far-reaching effect upon other forms of life that the 

 mind of man may never be able fully to trace and grasj) them. 

 The migrations of birds are so vast and widespread that the 

 movements of many species arc still more or less shrouded 

 in mystery. We do not yet know, for instance, just where 

 certain common birds pass some of the winter months. Some 

 species sweep in their annual flights from Arctic America 

 to the plains of Patagonia, coursing the entire length of the 

 habitable portion of a hemisphere. Many of the l)irds that 

 summer in northern or temperate America winter in or near 

 the tropics. Some species remain in the colder or temperate 

 regions only long enough to mate, nest, and rear their young, 

 and then start on their long journey toward the equator. 



The annual earth-wide sweep of the tide of bird life from 

 zone to zone renders the study of the relations of l)irds to 

 other living forms throughout their range a task of the 

 utmost mao^nitude. This vast migration at once suo^o-ests 

 the question. Of what use in nature is this host of winged 

 creatm-es that with the changing seasons sweeps over land 

 and sea? 



Our first concern in answering this question is to deter- 

 mine what particular office or function in the economy of 

 nature birds alone are fitted to perform. The relations 



