FAMILY HirundinidcB 



name as well, and is commonly called the 

 eave swallow. The brownish plumage, squar- 

 ish tail and buffy forehead are the distinguish- 

 ing field marks of this species. The call note, 

 too, is quite different from others of the 

 family. It is a peculiar purring note, easily 

 remembered if given careful attention. It is 

 interesting to know that each species of swal- 

 low has its own distinctive call note which a 

 careful student learns to recognize without 

 seeing the bird as it flies overhead. 



^ Tree sw allow y I ridoprocnebicolor. 5.75 



Distribution: North America in 

 general; on the Pacific Coast from Alaska to 

 California; wintering south of the United 

 States in Mexico and Central America. 



The tree swallow, or white-bellied swallow, 

 is far less common than the violet-green in 

 the northern part of its range. It builds its 

 nest in hollow trees or old woodpeckers' ho^es, 

 and rarely in a bird box. The tree swallow 

 with its steely blue upperparts and pure 

 silky white underparts is considered the 

 most beautiful of all the swallows. It is 

 so nearly like the violet-green swallow^ in 

 appearance, however, that only a good bird 

 student can identify it on the wing at any 

 distance. 



54 



