THE BIRD STUDY BOOK 



the streams of their nativity when the spirit of 

 migration sweeps over the shoals into the abysmal 

 depths. There are butterflies that in companies 

 rise from mud puddles beside the road and go dan- 

 cing away to the South in autumn. The caribou, 

 in long streams, come southward over the barrens 

 of Labrador when the word is passed, and even squir- 

 rels, over extended regions, have been known to 

 migrate en masse for hundreds of miles. There is, 

 however, no phase of the life of birds which is quite 

 so distinctive. The extent and duration of their 

 migrations are among the most wonderful phenomena 

 of the natural world. 



Ornithologists have gathered much information 

 regarding their coming and going, but knowledge 

 on many of the points involved is incomplete. It is 

 only of recent years that the nest of the Solitary 

 Sandpiper has been found, and yet this is a very 

 common bird in the eastern United States in cer- 

 tain seasons. Where is the scientist who can yet 

 tell us in what country the common Chimney Swift 

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