212 THE ECONOMIC IMPORTANCE OF ANIMALS 



Americans. The recent McLane bill which aims at the protec- 

 tion of migrating birds and the bird-protecting clause of the 

 recently passed tariff bill shows that this country is awaking to 

 the value of her bird life. Without the birds the farmer would 

 have a hopeless fight against insect pests. The effect of killing 

 native birds is now well seen in Italy and Japan, where insects are 

 increasing and do greater damage each year to crops and trees. 



Of the eight hundred or more species of birds in the United 

 States, only six species of hawks (Cooper's and the sharp-shinned 

 hawk in particular), and the great homed owl, which prey upon 

 useful birds ; the sapsucker, which kills or injures many trees be- 

 cause of its fondness for the growing layer of the tree ; the bobolink, 

 which destroys yearly $2,000,000 worth of rice in the South ; the 

 crow, which feeds on crops as well as insects; and the English 

 sparrow, may be considered as enemies of man. 



The English Sparrow. - The English sparrow is an example of 

 a bird introduced for the purpose of insect destruction, that has 

 done great harm because of its relation to our native birds. In- 

 troduced at Brooklyn in 1850 for the purpose of exterminating 

 the cankerworm, it soon abandoned an insect diet and has driven 

 out most of our native insect feeders. Investigations by the 

 United States Department of Agriculture have shown that in 

 the country these birds and their young feed to a large extent 

 upon grain, thus showing them to be injurious to agriculture. 

 Dirty and very prolific, it already has worked its way from the 

 East as far as the Pacific coast. In this area the bluebird, song 

 sparrow, and yellowbird have all been forced to give way, as well 

 as many larger birds of great economic value and beauty. The 

 English sparrow has become a pest especially in our cities, and 

 should be exterminated in order to save our native birds. It is 

 feared in some quarters that the English starling which has re- 

 cently been introduced into this country may in time prove a 

 pest as formidable as the English sparrow. 



Food of Snakes. - Probably the most disliked and feared of all 

 animals are the snakes. This feeling, however, is rarely deserved, 

 for, on the whole, our common snakes are beneficial to man. The 

 black snake and the milk snake feed largely on injurious rodents 



