THE TRAVELS OF BIRDS 



may have something to do with the courtship 

 customs of that time of year. 



A PATHWAY IN THE AIR 



It is most interesting to observe how closely 

 widely separated flocks or groups of migrating 

 birds follow the same invisible pathway through 

 the air. I have seen Swallows flying northward 

 in small bodies which followed each other at 

 short intervals. The last ones to pass would be 

 far out of sight before the next birds arrived, 

 for they were flying not more than twenty feet 

 above the earth; but each Swallow followed 

 those that had gone before it as though guided 

 by the marks of wing beats in the air. 



In the same way I have seen Herring Gulls 

 in the spring migrating over my home at Engle- 

 wood, New Jersey. They were flying toward 

 the northeast in flocks of fifteen to twenty birds 

 and were about one thousand feet above the 

 earth. At times several flocks could be seen at 

 one time. Then several minutes would pass 

 without any more Gulls appearing. But soon 

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