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NATURE'S CALENDAR 



September 14 



ing across its bright disk, at heights a 

 quarter or half a mile above the earth, for 

 now, as in the spring, the migratory jour- 

 neys are made mostly in the dark hours, 

 the daylight being given to resting, feed- 

 ing, and some leisurely progress. That 

 the necessity for feeding by day is the 

 main reason why they fly at night is 

 shown by the fact that such birds as 

 swallows, swifts, nighthawks, and certain 

 others that obtain their food on the wing, 

 do not do this, but proceed wholly by 

 daylight, foraging as they fly. 



In clear nights, and especially when the 

 moon shines, the woodland birds collect 

 at sunset in little bands and rise straight 

 up to a considerable height, then bear 

 away on their course. But when the 

 nights are dark and misty, as so often 

 happens in early autumn, yet not so 

 stormy as to stop them, the birds skim 

 low over the tree-tops and houses, fueling 

 their way along and often getting confused 

 and scattered. On such nights no one 

 who is out in a quiet, open place, where 

 the chatter of the katydids and other 

 noises do not fill his ears, can fail to hear 

 in the gloom above him the almost inces- 

 sant voices of passing birds, calling to one 

 another in the effort to keep together as 

 they grope their way along. It is one of 

 the pleasures of the autumn to listen to 

 these anxious-hearted, invisible travellers, 

 most of whom will be recognized by the 

 trained ear. 



September 15 



