THE BIRDS' TIME-TABLE 



they will carry on constant warfare against the 

 caterpillars, cut-worms, weevils, and other 

 harmful insects, which, if they were not preyed 

 on by birds, would destroy our crops. 



RETURNING TO THE WINTER HOME 



No sooner has the invasion ended than prepa- 

 rations for the retreat to winter quarters begin. 

 We have already seen that in early June the 

 Crackles and Robins drill their families for the 

 great journey by daily trips to and from the 

 roosting places. In July the young Swallows 

 are given their lessons; and late in that month 

 the Bobolink actually begins his southern mi- 

 gration. By August 20, the retreat is well under 

 way and from that time until September 30, our 

 woods are again thronged with traveling War- 

 blers, Vireos, Flycatchers, and other birds. Most 

 of them have changed the bright uniform of 

 spring for a duller coat in which we may find it 

 difficult to recognize them. 



In October they will be followed by the Jun- 

 cos and Tree Sparrows; and in November, if 

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