GREEN, GREENISH GRAY, AND OLIVE 4383 
semble one closely. In fact, unless the bird be seen to fly 
off the nest or to it, the discovery of one of these dainty 
homes is almost impossible. One nest, now in the col- 
lection of Mr. William Brewster, at Cambridge, Mass., 
is composed of fine moss and willow down, decorated 
with tiny shreds of bark, flakes of wood, and flakes of 
whitewash fastened securely with cobwebs ; it was placed 
on a knot in a rope hanging from the roof of a wood- 
shed. The construction and materials mimicked the 
rope and knot on which it was placed. Mr. Bryant 
records another, built on a projecting splinter of a wood- 
pile at a height of two feet. Here, as seemingly under 
all circumstances, the bird had tried to imitate the sur- 
roundings, and to so place its home that it would be 
more or less protected by an overhanging branch, leaf, 
or some other object. 
459. OLIVE-SIDED FLYCATCHER. — Contopus borealis. 
Famity : The Flycatchers. 
Length : 7.10-7.90. 
Adults: Upper parts dark-brownish slate, with darker shaft streaks on 
some of the feathers; conspicuous tuft of white cottony feathers 
on each side of rump (generally concealed by wings); under parts 
white through the middle from chin to crissum ; the sides dark and 
somewhat streaked. 
Young: Like adults, but wing-coverts tipped with- brownish instead of 
white. 
Geographical Distribution: Through the mountainous regions of North 
America west of Rocky Mountains to Pacific Coast ; north to Hudson 
Bay; south in winter as far as Peru. 
California Breeding Range: In Transition and lower Boreal zones 
throughout the State. 
Breeding Season: June 1 to August 1. 
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