FAMILY MicropodidcB 



of the Cascades and Sierra Nevadas. Migrat- 

 ing to Mexico and Central America. 



The Vaux swift is confined almost ex- 

 clusively to the Pacific Slope and is a bird of 

 the mountains rather than of the valleys. It 

 is rarely seen in any numbers, a dozen or 

 more being considered a large flock. At times 

 it may be seen by twos or threes sailing over 

 the open country on the way from one high 

 ridge to another, and at certain places along 

 the Columbia River it may even be called 

 common. In California it is reported as being 

 common in the coast districts from San 

 Francisco Bay northward. 



In coloration the Vaux swift is sooty brown 

 instead of the sooty gray of the chimney 

 swift. Vaux swifts may be distinguished at 

 a distance from the swallows by the peculiar- 

 ity of their flight. The narrow crescent- 

 shaped .wings move with a rapid bat-like 

 motion, alternating several wing beats with a 

 swift gliding movement, darting here and 

 there with incredible speed. When in the 

 mountains observers have noticed the swifts 

 circling close overhead as if curious about 

 the intruders, and occasionally they will come 

 close to the ground in the open country, 

 beating about over the fields in a curious 

 zigzag manner. 



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