206 ANIMAL BIOLOGY 



and considerably limited in numbers in the country. 

 Efforts to exterminate English sparrows have met here 

 and there with success, but to rid the whole country of 

 the pests seems now a hopeless task. 



The great value of most kinds of birds has led to the 

 passage of various laws for their protection. For game 

 birds there is usually a "closed season" during which 

 hunters cannot shoot them without incurring a legal 



FIG. 161. A screech owl. (From photo by Mr. Tracy Storer.) 



penalty. In several states the song birds and many 

 other kinds are protected at all times. But notwith- 

 standing these protective measures there is a vast slaughter 

 of bird life that is leading to a marked reduction in the 

 number of birds. The robbing of birds' nests by boys 

 destroys many valuable birds, and the still more extensive 

 collection of the eggs of ducks, gulls and other birds 

 which commonly nest upon islands or near rocky shores 

 destroys many more. Aside from the hunting of recog- 

 nized game birds there is in many places a wholesale 



