Nests in Buildings, Bridges, Walls, Etc. 
nests, the first nest being begun about the middle of April and 
the second toward the middle of July. Both nests are built near 
or about in the same place, the first often being torn down to 
make room for the second. The birds will seldom forsake the 
nest, even when most of the eggs are taken; and I have removed 
a nest containing three eggs in order to photograph it, and even 
though it was not returned to its original place the female con- 
tinued laying as if it had never been disturbed. After the young 
leave the nest they stay together, generally sitting close to each 
other on a low branch, taking short flights together or singly; 
this they do for five or six days, when they gradually become 
separated, the parent bird in the meantime feeding them. 
468. Yellow-bellied Flycatcher: Empidonax flaviven= 
tris Baird. 
Aduit—Upper parts dark olive green; tail and wings dull grayish 
brown, the wings having two very pale yellowish bars; the 
belty lemon yellow, breast and side greenish yellow. 
Length—5.63. 
Breeding Range—The more northern parts of the United States; 
not south of Berkshire County, Massachusetts. 
The nest is made of moss, lined with fine grass and fine black 
roots and pine needles, usually imbedded in moss in the upturned 
roots of a fallen tree, or even in a decayed stump. 4 and pos- 
sibly 5 eggs are laid; they are creamy white, speckled or spotted, 
chiefly at the larger end, with light chestnut. Size—.7o x .50. 
Not very much is known of the breeding habits of this bird, 
comparatively few nests having been taken; breeding, as they 
usually do in the forests remote from civilisation, together with the 
fact that the nest is carefully concealed and therefore very hard to 
find, renders the studying of their nesting habits an extremely 
difficult task. ‘ 
The breeding season probably begins in June. 
486a. Northern Raven: Corvus corax principalis Ridgw. 
It is possible that this sub-species of raven breeds within the 
United States, although I find no authentic record of its doing so. 
The bird is blue black, and is about four or five inches longer 
than the common crow (Corvus americanus). 
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