FLYCATCHERS 257 



1 . 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 . . richardsouii, p. 258. 



Subgenus Nuttallornis. 



459. Contopus borealis (Simms.). Olive-sided Flycatcher. 

 Adults. — Under parts with whitish median tract between dark, somewhat 



streaked lateral parts, white sometimes 

 faintly tinged with yellow ; upper parts 

 sooty, conspicuous tuft of white cotton}/ 

 feathers on sides of rump (usually con- 



cealed by wings). Young: similar, but liy. JuJ. 



wing coverts tipped with butf y, or brown- 

 ish instead of w hite. Length : 7. 10-7.90 ; wing 3.90-4.50, tail 2.80-3.50, 

 exposed culmen .58-. 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 ; migrates 

 to Peru, Central America, Columbia, and northern Peru. 



Nest. — Small, of wiry materials fastened skillfully to branches of conif- 

 erous trees, 40 to ()0 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 ])u-j)ip' of the olive-sided calls 3'our 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 tir 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 pv-pip', pu-pu-pio' , pu-pij)', pv-pu-pio', came 

 down to us in soothing cadence till the camp-lire shone in the dark- 

 ness. 



Subqrenua Contopus. 



460. Contopus pertinax pallidiventris Chapm. Coues Fly- 



(A K'UKK. 



Adults. — Up/jer parts grai/ish brown, tinged with olive ; under parts nearly 

 uniform olin grai/, rhin slightly whitish, belly and under tail coverts dull 

 yellow ish ; first (jnill iiinrli shorter th.m 

 fourth. Young: similar, but wing cov- 

 erts tipped with butl'v or l>ro\snish. 

 Length : 7.70-8.UO, wing ;;..S(,M.4:). tail 



;;.(;(^-;;.'.M.. ^ _ j.,,^, _. 



liemarks. — The Cou«*s flycatclu'r is 

 about the size of the olive-sided, but its under parts are strikinj;ly uniform 



