USEFUL BIRDS AND THEIR PROTECTION. 
INTRODUCTORY. 
THE UTILITY OF BIRDS IN NATURE. 
There is no subject in the field 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 grasp them. 
The migrations of birds are so vast and widespread that the 
movements of many species are still more or less shrouded 
in mystery. We do not yet know, for instance, jus where 
certain common birds pass some of the winter months. Some 
species sweep ih their annual flights from Arctic America 
to the plains of Patagonia, coursing the entire Jength of the 
habitable portion of a hemisphere. Many of the birds 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 birds to 
other living forms throughout their range a task of the 
utmost magnitude. This vast migration at once suggests 
the question, Of what use in nature is this host of winged 
creatures 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 
