TREE SWALLOW. 
WHITE-BELLIED SWALLOW. SINGING SWALLOW. 
TACHYCINETA BICOLOR. 
Cuar. Above, rich steel blue, wings and tail with green reflections ; 
beneath, white. Length about 6 inches. 
West. Ina cavity of a tall dead tree, — often a deserted Woodpecker’s 
hole, — sometimes in a bird box; made of grass and straw, lined with 
feathers. 
Zggs. 4-9 (usually 5); white; 0.75 X 0.55. 
This species, less common than the Barn Swallow and nearly 
allied to the common Martin, arrives in Pennsylvania and 
New England about the middle of April, and extends its migra- 
tions over the continent nearly to the Arctic circle, having 
been seen by Dr. Richardson in the latitude of 53°; it is 
also abundantly dispersed over the Rocky Mountains and the 
Columbia River, where it breeds, as well as around Hudson 
Bay and throughout the Northern and Middle States. On its 
arrival, like many other species, it seeks out the society of 
man and frequently takes possession of the mansion of the 
Martin. When these advantages are unattainable it will be 
content with the eaves of some deserted dwelling, a hollow 
tree, its ancient residence, or even an horizontal branch when 
large and convenient. 
The note of these birds is a shrill, lively, warbling twitter ; 
but they are more quarrelsome and less sociable in the breed- 
