VIREOS 395 



7. Darker, wing bars narrower. California. 



huttoni, p. 399. 



7'. Paler and grayer, wing bars broader. Texas and Arizona. 



Stephens!, p. 399. 



6'. Wing bars tinged with yellow. Washington and Oregon, 

 wintering in California obscurus. p. 399. 



Subgenus Vireosylva. 



Spurious primary if present decidedly shorter than tarsus ; wing without 

 light bands. 



624. Vireo olivaceus (Linn.). RED-EYED VIREO. 



Adults. Top of head gray, conspicuously bordered by white superciliary 

 and narrow black line ; -blackish line through eye ; rest of 

 upper parts olive green; wings without bands or spurious 

 primary ; under parts clear white. Young : similar, but back 

 brownish ash ; sides washed with brown. Length : 5.50-6.50, 

 Fig. 489. wing about 3.10-3.30, tail 2.15-2.30, exposed culmen, .50- 



.55. 



Distribution. Breeds from the arctic regions south chiefly in the north- 

 eastern United States, but extending through Florida and to the Gulf of 

 Mexico ; west to Montana and Washington ; migrates to South America. 1 



Nest. Hung rather low from a forked twig of a tree, made of strips 

 of birch and inner bark, dead leaves, and vegetable fibers, often patched 

 with bits of wasp nest and lined with pine needles, or stems and rootlets. 

 Eggs : 3 to 5, white, lightly specked with reddish brown, chiefly around 

 the larger end. 



Food. Insects and small berries. 



The eastern red-eyed vireo is found occasionally in Colorado at the 

 base of the foothills, and has been recorded as far west as British 

 Columbia. 



625. Vireo flavoviridis (Cass.). YELUOW-GREEN VIREO. 



Like olivaceus, but sides and flanks bright olive green, axillars and 

 under tail coverts sulphur yellow. Length : 6.25-6.75, wing 2.80-3.20, tail 

 2.05-2.50. 



Distribution. Valley of the Lower Rio Grande in Texas, south to South 

 America ; accidental in Quebec and at Riverside, California. 



627. Vireo gilvus (VieilL). WARBLING VIREO. 



Adults. Upper parts olive gray, grayest on head and most olive on rump 

 and upper tail coverts ; white streak through eye ; wings and 

 tail dusky brown, unmarked, wing with a well-developed spu- 

 rious primary ; sides of head pale brownish or buffy ; under 

 parts white, shaded with olive yellow on sides. Young : top 

 Fig. 490. of head and hind neck pale grayish buff ; rest of upper parts 

 buffy, wings with buffy bars ; under parts pure white, except 

 for yellowish tail coverts. Length: 5.00-5.50, wing 2.65-2.95, tail 2.10- 

 2.40, bill from nostril .30-.32, depth at base .15-.18. 



Distribution. North America in general from Great Slave Lake to 

 northern Mexico ; breeds throughout the greater part of this range. In 

 winter to southern Mexico. 



Nest. Similar to that of the red-eye, but smoother and more compact ; 

 hung in trees, usually at a considerable height, in open copses, along banks 



