OUR POLICEMEN OF THE AIR 



No ONE can read the preceding 

 pages without an immediate desire 

 to become personally acquainted 

 with each of the handsome creatures 

 pictured. How indefatigably the wrens, 

 swallows, nighthawks, owls, red-tailed 

 hawks, etc., are working to lighten our 

 labors on the farm and orchard. 



Birds are our best friends. They are 

 our most efficient allies in the incessant 

 warfare that must be waged by man 

 against insect pests. Notwithstanding 

 our efforts, insects are not diminishing 

 in number, but in many localities are in- 

 creasing. What would happen were 

 birds exterminated no one can foretell 

 with absolute certainty, but it is almost 

 certain, says Dr. Henshaw, that within a 

 limited time not only would it be impos- 

 sible to grow fruits and grain, but the 

 greater part of our vegetation would be 

 destroyed.* The more carefully birds' 

 habits are studied and their food inves- 

 tigated, the more apparent it is that man 

 cannot do without them. 



Pages 669-697 are an admirable illus- 

 tration of the educational work con- 

 ducted by our U. S. Biological Survey. 

 The temptation to shoot a hawk or owl, 

 perching or flying, which now is almost 

 irresistible to many, will soon disappear 

 when the man with the gun realizes that 

 he is seeking to put a friend to death. 



But the Biological Survey does not 

 confine its studies to birds alone; it also 

 helps to protect us against four-footed 

 pests. Its experts have shown how 

 wolves, which in recent years have be- 

 come very numerous and destructive on 

 cattle and sheep ranges, may be de- 

 stroyed by poison, and it has recom- 

 mended measures which, if energetically 

 and persistently pursued, will probably 

 result in the practical extermination of 

 these savage animals. In some sections 

 of the United States the damage by 

 meadow and house mice, by prairie dogs, 

 rats, gophers, ground squirrels, and other 

 small gnawing animals amounts to mil- 

 lions of dollars a year. One of the small 



* See "Policemen of the Air," by Henry W. 

 Henshaw, in the Nationai, Geographic Mag- 

 azine, February, 1908. 



ground squirrels of Washington State 

 injures the wheat crop in a single county 

 of that State to the extent of half a mil- 

 lion dollars annually. The Survey men 

 are successfully devising a method to de- 

 stroy these pests, and thus relieve this 

 serious drain on the farm. 



An important duty of the Biological 

 Survey is to prevent the entrance into 

 the United States of undesirable bird or 

 animal immigrants. "The English spar- 

 row serves as an ever-ready example of 

 the disastrous consequences of the un- 

 wise introduction of a species into a new 

 home. Under the present law and sys- 

 tem of inspection, this pest could never 

 have obtained a foothold in America, 

 since so well known were the bird's 

 habits in its native land that its disas- 

 trous career on this continent would 

 have been foreseen and its entry pro- 

 hibited. 



"Under the mistaken idea that the 

 mongoose would prove beneficial by de- 

 voting itself to the destruction of small 

 rodents, and ignorant of the fact that the 

 animal is omnivorous and one of the 

 most destructive creatures in existence, 

 more than one attempt has been made to 

 import it into the United States, where 

 its successful introduction would prove 

 nothing less than a national calamity." 



On pages 669-697 references are made 

 to other publications of the Biological 

 Survey. Several of them are out of 

 print, but the majority may be obtained 

 by persons desiring further information 

 by applying to the Superintendent of 

 Documents, Washington, D. C, and in- 

 closing the price of the bulletins desired. 



Farmers' Bulletin 54 and 497, each $0.05 



Biological Survey Bulletins 9, 13, 23, 



each 05 



Biological Survey Bulletin 15 10 



Biological Survey Bulletin 21 15 



Biological Survey Bulletins 30 and 44, 



ieach. 20 



Biological Survey Bulletin 32. .25 



Biological Survey Bulletin 34 40 



Biological Survey Bulletin 39 30 



Biological Survey Bulletin 37 35 



Yearbook, Department of Agriculture, 



1895 55 



Biological Survey Bulletins 3 and 24 are out 

 of print and cannot be supplied. 



698 



