396 VIREOS 



of streams, or in shade-trees along' streets. Eggs : 4 or 5, white, spotted 

 around larger end with reddish, dark brown, and lilac. 



Colorless as this small leaf-tinted bird may seem in coat, character, 

 and song, its voice is nevertheless one of the sunny warbled rounds 

 that gives good cheer to the western mountain forests. 



In Colorado, Prof. Cooke says, it breeds sparingly on the plains 

 and abundantly in the mountains up to 10,000 feet, especially in the 

 aspens. On San Francisco Mountain. Arizona, Dr. Mearns found it 

 in fall in the rank growth of annuals along streams in company with 

 terrestrial warblers. 



But, though a mountain dweller, the little vireo is also a village 



bird, leaning over and craning its neck to examine the leaves for 



worms as carefully in a Utah garden as in the retirement of the 



forest. 



Subgenus Lanivireo. 



Spurious primary if present decidedly shorter than tarsus ; wing with two 

 white bars. 



629. Vireo solitarius {Wils.). Blue-headed Vireo. 



Adults. — Top and sides of head dark gray in sharp contrast to white loral 

 streak, orbital ring and throat ; back olive green ; wings with two white bars ; 

 under parts clear white, shaded with olive and yellow on sides and flanks. 

 Young in first ivinter : anterior upper parts grayish brown, under parts dull 

 buffy white. Length : 5-6, wing 2.90-3.00, tail 2.10-2.20, bill from nostril 

 .28-.30. 



Distribution. — Breeds from Great Slave Lake and Hudson Bay to south- 

 ern New England and the noi'thern part of the lake states, and from the 

 Atlantic coast to Dakota ; migrates to Guatemala. 



Nest. — In woods, in undergrowth, or hung from lower branches of small 

 trees, like that of the red-eye, but often decorated with catkins. Eggs : 

 usually 5, white, spotted mainly with reddish brown around the larger end. 



Food. — Chiefly insects. 



629a. V. S. cassinii {Xantus). Cassin Vireo. 



Adults. — Top and sides of head gray in sharp contrast to white of loral 

 streak, orbital ring, and throat; back dull 

 olive green ; wings with two clear white 

 bands ; under parts clear white, washed 

 with yellow and olive on sides and flanks. 

 Young in first icinter : dull grayish brown 

 above, dull buffy below. Length : 5.00- 

 5.60. wing 2.85-3.00, tail 2.10-2.30, bill 

 from nostril .28-.31, tarsus .70-.78. 



Distribution. — Breeds from British Co- 

 lumbia and Idaho south along the Pacific 

 coast region and Nevada to Lower Cali- 

 Fig. 491. fornia; migrates to Arizona, New Mexico, 



and northern Mexico. 

 Nest. — In oaks, manzanita, and buck brush, pendant, compactly woven 

 and lined with light-colored grasses, decorated with jjieces of white cocoon. 

 Eggs : 4 or 5. 



