184 
Distinctions. The even blackness with pronounced steely reflections of the upper 
parts and pure whiteness below are distinctive. 
Field Marks. The pure unmarked whiteness of the underparts make an easily re- 
cognized field mark. Young birds have the black above replaced with dull brown and 
a suggestion of suffused brown on the sides of the breast, but this never forms a con- 
tinuous band across the breast as in the Bank Swallow. 
Nesting. In old woodpecker’s holes in dead stubs, hollow trees, or bird boxes. Lined 
with grasses and feathers. 
Distribution. America north to near the limit of trees. 
Though normally using woodpecker’s holes in dead stubs over the 
water the Tree Swallow is easily induced to nest in boxes in the garden. 
The beauty of its bright iridescence and the grace of its flight make ample 
payment for the work of preparation, even if its presence were not an 
important safeguard against insects in the garden. The continued existence 
of the species is threatened through the growing scarcity of natural nesting 
sites unless an effort is made to supply the nests artificially. 
616. Bank Swallow. sAND MARTIN. FR.—L’HIRONDELLE DE RIVAGE. Riparia 
riparia. L, 5-20. Plate XXXVII A. 
Distinctions. Dull brown instead of iridescent coloration of back, and white under- 
parts with distinct dark breast-band are distinctive. The band is always full and com- 
plete and the white pure. The complete breast-band will separate the Bank from the 
young Tree Swallow; and from the Rough-winged in which the white is not pure and 
the breast and throat are evenly suffused with ashy brown. 
Field Marks. The white underparts crossed by a conspicuous dark bar makes the 
best field mark. 
Nesting. Nearly every one has seen how quickly the exposed sides of a sand or 
gravel pit excavation become pitted with the small nesting holes of these swallows. 
Too often the heedless small boy digs them out. Not only is this dangerous to the boy 
from the possibility of the bank caving, but it is striking a direct blow at the existence of 
one of the farmer’s best friends. 
617. Rough-winged Swallow. Stelgidopteryx serripennis. L, 5-75. Much like the 
Bank Swallow in general coloration, but with the breast and throat suffused with 
light ashy-brown instead of being crossed with a sharp brown band. 
Distinctions. The above difference, together with the absence of much pure white 
below and any white on throat are diagnostic. Grown birds have the small outer web of 
the outer primaries converted into a series of fine recurved hooks almost too small to 
see with the naked eye, but obvious to the touch as the finger is drawn along the edge 
towards the tip. Young birds do not show this well, sometimes not at all, and various 
stages of its development appear. It is present in some degree in all spring specimens. 
Field Marks. The best field mark by which to separate the Rough-winged from 
the Bank Swallow is the evenly suffused breast instead of the white one with broad dark 
bar. In watching a mixed flock the Rough-wings can usually be picked out by the slightly 
redder or rusty-coloured back which seems more conspicuous in life than in the hand. 
Nesting. Similar to the Bank Swallow, but more solitary and perhaps more given to 
nesting in crevices in rock piles, cliffs, or masonry. 
Distribution. America. North to across the Canadian border in the lower Great 
Lakes region. 
The Rough-wings belong to a genus widely scattered over the world, 
all exhibiting the peculiar modification of the wing which cannot be 
accounted for in the present state of our knowledge. 
FAMILY—BOMBYCILLIDHZ. WAXWINGS. 
The Waxwings are striking birds, distributed over the northern parts of 
both the New and Old Worlds. They are represented in America by two 
species so well characterized in form and colour and so nearly alike that 
