160 TREE SWALLOW. 
The Bank Swallow winters in the tropics and reaches 
us 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 
Rough-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 Rough-wing is a more south- 
ern bird, being rare north of southern Connecticut. It 
resembles the Bank Swallow, but differs chiefly i in having 
the whole breast brownish gray. It nests in holes in 
banks, and also about stone bridges, trestles, and sia 
structures. 
Though very generally distributed, there are lassi 
areas within the breeding range of the Tree Swallow 
Tree Swallow, Where it is known only as a migrant. 
Tachycineta bicolor. In the wilder part of its range it nests 
(Frontispiece.) in hollow trees; 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, coming to us from Florida early in April. It 
is also the last of its family to leave us in the fall, often 
remaining near New York city until October 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. 
