The Policemen of the Air 



8 9 



for American foodstuffs never 

 ceases for a moment. To sup- 

 ply this triple demand, better 

 methods of tillage must be de- 

 vised and more and more acre- 

 age must be devoted to agri- 

 culture. In part this need of 

 creased acreage is to be met by 

 irrigation projects, which 

 when they materialize will 

 make available for farms and 

 homes millions of acres of 

 sterile desert. 



WITHOUT BIRDS SUCCESSFUL 

 AGRICULTURE WOULD BE IM- 

 POSSIBLE. 



But increased acreage and 

 larger crops mean a vast in- 

 crease of insect life as the re- 

 sult of a more constant and 

 abundant supply of food. 

 Even now, despite the inces- 

 sant warfare waged against 

 them, insects are not diminish- 

 ing in numbers. On the con- 

 trary, in many localities they 

 are increasing. Especially are 

 new pests finding their way 

 into the country, and as these usually 

 are unaccompanied by the enemies 

 which keep them in check at home, 

 they frequently run riot in the new- 

 these usually are unaccompanied by the 

 enemies which keep them in check at 

 home, they frequently run riot in the new- 

 found Paradise. Well-known instances 

 are the cotton boll weevil and the gypsy 

 and brown-tailed moths. It is estimated 

 by entomologists that the annual loss of 

 agricultural products from insect ravages 

 in the United States is not less than 

 $500,000,000. To birds, then, we must 

 look for allies in the continuous warfare 

 against insect pests, and if they are to 

 play even the same relative part in the 

 future as they have in the past, they 

 should not only be protected, but de- 

 termined efforts should be made to in- 

 crease their numbers and make their 

 work more effective. 



What would happen were birds ex- 

 terminated no one can foretell with abso- 



From the Biological Survey 

 CLARK CROW 

 A bird of the high pine forests in the Rocky mountains 



lute certainty, but it is more than likely — 

 nay, it is almost certain — that within a 

 limited time not only would successful 

 agriculture become impossible, but the de- 

 struction of the greater part of vegeta- 

 tion would follow. It is believed that a 

 permanent reduction in the numbers of 

 our birds, even if no species are actually 

 exterminated, will inevitably be followed 

 by disastrous consequences. 



The strict enforcement of bird-protec- 

 tion laws is the more important, since of 

 recent years thousands of immigrants 

 from the south of Europe have reached 

 our shores who appear to be wholly 

 ignorant of the value of birds to man ex- 

 cept for food, and who exhibit a total dis- 

 regard for the spirit of bird laws, and 

 little for the letter, except in so far as in- 

 fraction brings sure and swift punish- 

 ment. In the eyes of many of these re- 

 cent comers, no bird is too small to serve 

 as food ; no bird too valuable to serve as 

 a mark for the earn. Birds' song:s have 



