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 (Su-ains.). Olive-sided Flycatcher. 

 Adults. — Under jiarts with irhitish median tract between dark, somewhat 



streaked lateral parts, white sometimes 

 faintly tinged with yellow; upper parts ..•^ r^s 



sooty, conspicuous tuft of white cotton// 

 feathers on sides of rump (usually con- 

 cealed by Avings). Young: similar, but Fig. :>;;j. 

 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 eulmen .5S-.70, tarsus .55-. 00. 



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 00 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 iu the Canadian forests throughout the United 

 States the pu-j)ip' 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 pn-pip' , pv-pu-pio', pu-pip , pu-pu-pio' , came 

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

 ness. 



Subg:enus Contopus. 



460. Contopus pertinax pallidiventris Chapm. Coues Fly- 



(.'ATCHKU. 



Adults. — Uj)/)er parts grai/ish hrmrn. thiged with olive ; under parts iiearlt/ 

 uniform olin grai/. rhin slightly whitish, btdly and undt-r tail coverts dull 

 yellowish ; first (juill much slutrlt-r tli.m 

 fourth. Young: similar, ])ut wing cov- 

 erts tipped with biitt'y or brownish. 

 Length: 7.70-S.U(), wing 3.80-4.45. t.iil 

 3.(')()-3.1M». ,,^, .... 



lif marks. — The Cones flycHlchn is 

 about the si/.e of the olive-sided, but its under parts arc stiikiii<;ly uniform 



