SWALLOW BOOSTS AND MIGRATION 



the top of a dune. They began to arrive about 

 six o'clock, and the majority came from the 

 west,— from the region of the. setting sun,— 

 and flew in a continuous sheet, perhaps a third 

 of a mile wide, skimming for the most part 

 close to the sand, but mounting occasionally 

 high into the sky. As the birds sped by me, 

 the}^ often flew within a few feet or inches, 

 and at times barely grazed the sand. Tree 

 swallow^s were in the majority, while barn 

 swallows formed perhaps a fourth part of 

 the whole, and there were a few bank but 

 no eave swallows. The characteristic notes 

 of the three species could be heard from time 

 to time, but the birds were for the most part 

 silent, although occasionally a barn swallow 

 would break forth into his always delightful 

 song. The flight was an irregular and waver- 

 ing one, but the multitudes were intent on 

 their goal, wearied, no doubt, by the day's 

 work and play. Occasionally two would stop 

 in their onward career, pla^^ully to attack 

 each other in mid-air, and at times, for no 

 apparent reason but as the impulse seized 

 them, a sudden upward or even retrograde 

 movement of all the birds would occur. The 

 sun set at five minutes of seven, but the birds 



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