INTRODUCTION 



etc.; they would be lifeless indeed. If the presence and 

 sight of our birds please a great many people they can be said 

 to have a very large aesthetic value. 



Certain species of birds, commonly known as Game Birds, 

 have another value in that they are pursued by sportsmen 

 for recreation and food. But by far the greatest value is an 

 economic one. Birds are literally worth their weight in gold, 

 and it behooves every one of us to see that they are kept 

 alive and in good health as far as we are individually and 

 collectively able. Yet it is only within a few years that birds 

 have come into their own and been reckoned at their true 

 worth as destroyers of injurious insects and consequently as 

 saviors of our crops. Only a few years ago one of our large 

 states was offering a bounty of 25 cents on each hawk and 

 owl killed, while as a matter of fact the destruction of each 

 one was costing the farmers in the neighborhood of $40 

 per year caused by damage done by the mice and insects that 

 each one of the birds of prey would have consumed in that 

 time. 



The temperature of the blood in birds is higher than in 

 other animals and the circulation is double and very rapid. 

 In order to supply fuel to maintain this temperature and 

 rapid circulation birds eat a great deal and the digestion is 

 very rapid. When food is abundant they eat more than 

 necessary and become very fat; when it is scarce they have 

 to cover much ground to find enough for their wants. Not 

 more than 2 per cent, of our native birds are destructive to 

 such a degree that the good they do does not more than make 

 amends. Less than 10 per cent., while not injurious in any 

 way, are of little or no account economically; the remainder, 

 nearly 90 per cent, of all our birds, are very valuable. They 

 are one of the most important balance springs of Nature, and 

 their office is to check any undue increase in any species of 

 insects. If a certain insect pest becomes superabundant, the 

 birds that feed upon it congregate, gorge themselves, raise 

 large families and return the following year in sufficient 

 numbers to quell the outbreak. This check works perfectly 

 upon native insects, but if a foreign one is brought to this 



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