VIREOS. 327 



consist of a series of guttural gurgles, squeaky whistles, and shrill pipes, 

 some of which might be attributed to the creaking weather vanes he 

 so often chooses as a perch. 



Family Vireonid^. Vireos. 



The Virecs, numbering about fifty species, are peculiar to America, 

 most of them being confined to Central and South America. Some 

 fifteen species, all belonging to the genus Vireo, reach the United 

 States. 



Vireos are for the most part arboreal, though several species haunt 

 the lower, rather than the higher growth. For small, insect-eating 

 birds they are rather slow in their movements. We do not see them 

 darting out after insects as do the Flycatchers, nor do they flit through 

 the foliage after the manner of many Warblers, but patiently glean 

 their food from the under surfaces of leaves, crevices in the bark, etc. 

 They are more musical than the small Warblers; all our species have 

 pleasing songs, and some of them are especially gifted. 



KEY TO THE SPECIES. 



A. With distinct white or yellowish white wing-bars. 



a. Eye-ring, or line from eye to bill, yellow. 



a^. Throat and breast bright yellow ; rump gray. 



628. Yellow-throated Vireo. 

 a2. Under parts white or whitish; sides and sometimes breast washed 

 with greenish yellow ; rump olive-green. 



631. White-eyeu Vireo. 631a. Key West Vireo. 



b. Eye-ring and line from eye to bill white. 

 b^. Head lead-blue ; wing over 2-50. 



629. Blue-headed Vireo. 629a. Mountain Vireo. 

 b^. Head grayish, nearly like back; wing under 2-50. 



633. Bell's Vireo (Illinois). 



B. Without white wing-bars. 



a. Under parts yellowish ; first primary as long as fifth. 



626. Philadelphia Vireo. 



b. Under parts white ; sides washed witli yellowish ; first primary -75 long. 



627. Warbling Vireo. 



c. Under parts white, with little if any yellowish on sides ; head with a 

 lead-gray cap, bordered by narrow black lines over the eye. 



624. Red-eyed Vireo. 623. Black-whiskered Vireo. 



623. Vireo calidris barbatulus (Cab.). Black-whiskered 

 Vireo. Ad. — Similar to the next specie.s, but somewhat duller above and 

 witli a fuscous streak on either side of the throat. 



Eange. — Cuba, Bahamas, and soutliern Florida; southward to Central 

 America in winter. 



Nest, pensile, of dry grasses, shreds of bark, cotton, lichens, and spiders' 

 web, lined with soft, cottonlikc fibers, suspended from a forked branch, five 



