BIRDS IN THEIR RELATION TO MAN 



215 



2. Which of the above purposes are proper ? 

 harmful ? Explain. 



Which most 



c. Some Causes of Decrease in the Number of Birds 



Observations. 1. Show how the following factors interfere 

 with the number of birds : 



Questions 



1. Do birds prefer wild or cultivated fruits ? 



2. What factor causes the greatest decrease in the number 

 of birds ? 



