142 1 GUIDE FOR THE STUDY OF ANIMALS 



4. What may retard migration ? What may hasten it ? 



5. What could prevent certain birds from ever coming 

 here, or, if they did come, from staying ? 



6. Name some birds which stay here permanently ; 

 some which come only for the winter ; some which come 

 for the summers ; some which merely pass through, going 

 and coming. 



7. Can you see anything which may determine whether 

 a bird will nest here or farther north ? If so, what is it ? 



8. Why is the house sparrow so successful ? 



9. Why are blue jays so nomadic in winter ? 



10. What months do the herring gulls stay here ? When 

 do they leave ? Where do they go when they leave ? 

 What do they do while they are gone ? When do they 

 return ? What is their economic value ? 



11. How many birds' nests have you seen this spring .' 

 To what kinds of birds did they belong .' If you have been 

 able to study one in particular, give its history as far as you 

 know it. 



12. Tell what you have learned by your own observa- 

 tion this spring concerning the kinds of food birds eat, and 

 their methods of obtaining food. 



13. What bird songs have you learned to know.'' When 

 do these birds sing most .■" Does a bird have more than 

 one song ? 



14. What birds have you seen near your home ? What 

 attached them to the vicinity.' How might you attract 

 more birds .' 



Birds ; Review and Library Exercise 



1. What are the distinguishing characteristics of birds ? 



2. Give the orders of birds, with the characteristics of 

 each order and an example of each. 



