2 BIRD FRIENDS 



reliable data regarding bird migration, comprising 

 over a half -million records. 



Changes due to migration. The conspicuous sea- 

 sonal changes in bird life which occur regularly 

 every year are due to bird migration. Birds may 

 be divided into four groups in accordance with the 

 portion of the year that they remain in a given 

 locality. Permanent residents remain in a locality 

 all the year. In the cold Northern States these in- 

 clude such common birds as the blue jay, nuthatch, 

 chickadee, downy woodpecker, goldfinch, and a few 

 others. Farther south the list becomes longer. 



Summer residents remain for the summer only, 

 during which season they are nesting. They spend 

 the winter in regions farther south. Most of the com- 

 mon birds found during the summer in the north- 

 eastern section of the United States belong to this 

 group, such as the oriole and the house wren. 



Winter residents are found in a locality only 

 during the winter, the summer being spent in re- 

 gions farther north. In the Northern States, this 

 group includes such birds as the winter wren, snow 

 bunting, tree sparrow, redpoll, and red-breasted 

 nuthatch. 



Transient visitants are birds which are seen for 

 a few weeks in the spring and again for a few weeks 

 in the fall as they are migrating. These birds spend 

 the winter farther south and the summer farther 

 north, and are seen only when passing through, on 



