THE TRAVELS OF BIRDS 



gay colors when traveling? Or, at any rate, why 

 should they don their courtship dress until the 

 return of the wedding season the following 

 Spring? 



It is not until the molt is completed and the 

 engine is in perfect order that the bird starts 

 on its travels. 



It only remains now to take the fuel aboard. 

 This with birds is nothing less than fat. A run- 

 ner training for a race tries to become thin. But 

 many birds when preparing for a long journey 

 put on a coat of fat. On it they live, to a greater 

 or less extent, during the time of migration. If 

 the bird can get food by the way, it is not neces- 

 sary to carry so much with him. Swallows can 

 feed as they fly. The Warblers and Vireos and 

 other birds that fly by night can hunt insects 

 during the day. But the Plover and other birds 

 that travel over the seas cannot stop for meals. 

 Like bears in winter they must live on them- 

 selves, that is, on their fat When they start, 

 their body is covered with a thick layer of fat, 

 but when they arrive at their journey's end it 

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