TREE SWALLOW. 215 



The Bank Swallow winters in the tropics and reaches 

 lis in the spring about April 20, remaining until late Sep- 

 tember. It is the smallest of our Swallows, measuring 

 only five inches in length, and is the only one, except the 

 Kough-winged Swallow, which has no metallic coloring 

 in its plumage, the back being plain brownish gray, the 

 under parts white, with a clearly defined brownish gray 

 band across the breast. The Kough-wing is a more south- 

 ern bird, being rare north of southern Connecticut. It 

 resembles the Bank Swallow, but differs chiefly in having 

 the whole breast brownish gray. It nests in holes in 

 banks, and also about stone bridges, trestles, and similar 

 structures. 



Though very generally distributed, there are large 

 areas within the breeding range of the Tree Swallow 

 Tree Swallow where it is known only as a migrant. 

 Tachyciiu'ta biroior. lu the wilder part of its range it nests 

 (Frontispiece.) ^^^ hollow trecs ; in the more settled 

 portions it uses bird-boxes. During recent years, as Mr. 

 Brewster has remarked, the always-present House Spar- 

 row has pre-empted the former abodes of the Tree Swal- 

 low, so that it no longer nests about our homes ; but as 

 a migrant its numbers are undiminished, and it is prob- 

 ably our most abundant Swallow. 



Being the only Swallow to winter in the eastern 

 United States, the Tree Swallow is the first to arrive in 

 the spring, coining to us from Florida early in Aj)ril. It 

 is also the last of its family to leave us in the fall, often 

 remaining near New York city until (3ctober 20. 



Immature birds have the upper parts brownish gray 

 instead of shining steel-blue, as in the adult, but in either 

 plumage the bird may be known by its pure white under 

 parts, which have given to it the name of White-bellied 

 Swallow. 



In the northern United States Martins are very local. 



