FLYCATCHERS 
257 
r. Length 5.90-6.75. 
2. Wings and tail shorter. Western Nebraska to Atlantic. 
virens, p. 258. 
2'. Wings and tail longer. Plains to Pacific . . richardsonii, p. 258. 
Subgenus Nuttallornis. 
459. Contopus borealis (Swains.). Olive-sided Flycatcher. 
Adults. — Under parts with whitish median tract between dark , somewhat 
streaked lateral parts , white sometimes 
faintly tinged with yellow; upper parts jot? 
sooty, conspicuous tuft of white cottony 
feathers on sides of rump (usually con¬ 
cealed by wings). Young: similar, but Fig. 332. 
wing coverts tipped with buffy, or brown¬ 
ish instead of white. Length: 7.10-7.90; wing 3.90-4.50, tail 2.80-3.50, 
exposed culmen .5S-.70, tarsus .55-.60. 
Remarks. — This is the only Contopus that has white cottony tufts on the 
sides of the rump, or first quill longer than fourth. 
Distribution. — Breeds in Canadian zone forests of North America from 
Hudson Bay south through the higher parts of the United States; mi¬ 
grates to Central America, Colombia, and northern Peru. 
Nest. — Small, of wiry materials fastened skillfully to branches of conif¬ 
erous trees, 40 to 60 feet from the ground. Eggs : usually 3, creamy, gen¬ 
erally wreathed with spots of brown and lavender. 
Food. — Winged insects, such as beetles, butterflies, moths, gadflies, and 
grasshoppers. 
In the high Sierra as in the Canadian forests throughout the United 
States the pu-pip' of the olive-sided calls your attention to a solitary 
bird with a dark gray breast and white median line, perched on the 
tip of an evergreen spire. Its body is quiet, but its head is turning 
from side to side, and suddenly it launches into the air, catches an 
insect, turns, and with wings and tail spread sails back to its perch. 
It calls a great deal in the twilight, and in the fir belt of Mt. 
Shasta, where its voice is one of the commonest forest sounds, as the 
evening shadows gathered over the noble trees under which we were 
camped, the mellow pu-pip ', pu-pu-pio ', pu-pip', pu-pu-pio', came 
down to us in soothing cadence till the camp-fire shone in the dark¬ 
ness. 
Subgenus Contopus. 
460. Contopus pertinax pallidiventris Chapm. Coues Fly¬ 
catcher. 
Adults. — Upper parts grayish brown , tinged with olive ; under parts nearly 
uniform olive gray , chin slightly whitish, belly and under tail coverts dull 
yellowish ; first quill much shorter than 
fourth. Young: similar, but wing cov¬ 
erts tipped with buffy or brownish. 
Length: 7.70-8.00, wing 3.80-4.45, tail 
3.60-3.90. _ Fig. 333. 
Remarks. — The Coues flycatcher is 
about the size of the olive-sided, but its under parts are strikingly uniform 
