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 Oreg-on, 

 wintering in California obscurus. p. 399. 



Subgenus Vireosylva. 



Spurious primary if present decidedly shorter than tarsus ; wing 1 without 

 bands. 



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



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, 

 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. 



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.). YELLOW-GREEN YIREO. 



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.gvajest on head and most olive on rum}) 

 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 



