240 



FIRST LESSONS IN ZOOLOGY 



or females show an)' differences, at this time, from their 

 more usual plumage ? After mating which bird selects 

 the nesting site ? Are old nesting sites preferred to new 

 ones ? If two broods arc reared is a new nest built ? 

 What are the principal causes of mortality among the 



eggs and young 

 during the breeding 

 season ? What in- 

 stincts or habits of 

 the parents have 

 direct reference to 

 these dangerous 

 conditions ? What 

 means of protecting 

 the nest are resorted 

 to ? What is the 

 behavior of tlie par- 

 ents to\\ards enemies 

 of the }'oung ? 



As explained in 

 Chapter XXI, the 

 geographical distri- 

 bution of animals is 

 a subject of much 

 importance, a n d 

 offers good oppor- 

 tunities in its more 

 local features for 



Fig io6.-- -Rnzorl.ill auk and ei,'t;. (Alter student field-WOrk. 

 phutoL^rapIi troni life 1 iv C. Kearton.} 



The field-study of 

 the birds of a given locality will comprise much obscrwation 

 bearing directl}- on zoogeograph)-, or the distribution of 

 animals. Certain biriis will he found to be limited to cer- 

 tain parts of c\'en a small regiim; the swimmers \\ ill jjc 

 found in ponds and streams, and the long-legged shore- 



