264 In Touch with Nature. 



the close of the summer the families of a neiVh- 



o 



borhood unite, and, urged by the approach of 

 autumn, the birds of a whole river valley will 

 merge into some two or three great flocks, and in 

 such close companionship migrate, or wander to 

 and fro, from one feeding-ground to another. 



When did birds begin to flock ? This has often 

 been asked, but never can be told. A close study 

 of this habit, as of many other bird-ways, points 

 to the conclusion that it is a survival of a much 

 more fixed one. There is now a vast deal of 

 irregularity about it. Certainly the red-winged 

 blackbirds, which form our largest flocks, are not 

 all gathered in, and single ones, pairs, and half a 

 dozen together remain all winter scattered up and 

 down the river valley. It is true of every other 

 flocking bird. The majority keep up the old cus- 

 tom, but so many stand aloof in every instance 

 that it might almost be said the custom is dying 

 out. 



Let it be borne in mind that I am writing of a 

 single locality, the Atlantic seaboard of the Middle 

 States, and of this region I am disposed to make 

 the statement that man has so modified the land 



