A Book on Birds 



A most interesting exception, however, to 

 this rule of night-migration which prevails 

 among so many is found in the case of the 

 White-breasted, or Tree, Swallows, who 

 invariably travel only from sunrise to sun- 

 set. They also start on their annual trips 

 southward earlier than most of the others, 

 often gathering in great flocks along the 

 seashore by the middle of August and 

 beginning their flight soon after. When 

 once they are all marshaled and ready to 

 proceed their numbers are simply astound- 

 ing. A friend of the writer once saw tens 

 of thousands of them gathered together of a 

 September evening upon a stretch of beach 

 near Surf City, New Jersey. They covered 

 the sand thickly in every direction for sev- 

 eral acres, hke soldiers in serried ranks, all 

 facing a stiff wind which was blowing from 

 the northeast at the time, and he first 

 thought them Chimney Swifts; but this was 

 only because their backs were toward him 

 at the moment, their pure white breast- 

 feathers — snowy and spotless from chin to 

 tail — showing a little later and fixing their 



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