JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 



631 



Family VIREONID^. Vireos. 



The Vireos number about 60 species confined to the Americas 

 and adjacent islands. They are insectivorous birds, usually dull 

 colored, inhabiting woodland and shrubbery, and build their nests 

 in trees or bushes. The song is a pleasing warble. 



ANALYSIS OF THE SPECIES. 



A. Wing without bars. 



Throat and under parts, more or less pale yellow; first primary, not short, 

 at least as long as fifth. 



PHILADELPHIA VIREO. 



Throat, breast, and belly, not yellow; crown nearly same color as back; 

 first primary, spurious; less than an inch long. 



WARBLING VIREO. 



Throat, breast, and belly, not yellow; sides of body, olive green; crown 

 very different from back; a blackish streak on sides of crown, and a whitish 

 streak over eye, first primary about as long as fifth. 



RED-EYED VIREO. 



B. Wing with white or whitish bars. 



(Formed by coverts being tipped with white or yellowish white.) 

 Eye ring, yellov.-; throat and breast, yellow; rump, grayish. 



YELLOW-THROATED VIREO. 



Eye ring, yellow; a spot in front of eye, yellow; throat, white or buffy 

 white; sides of body, yellow or greenish yellow. 



WHITE-EYED VIREO. 



Eye ring, white; crown and sides of head, slaty or plumbeous; wing, over 

 2.50 inches long, first primary very short. 



BLUE-HEADED VIREO. 



Eye ring, white or whitish, sometimes indistinct; wing, under 2.50 inches 

 long; first primary, small, about half as long as third; wing bar, narrow. 



BELL'S VIREO. 



Philadelphia Vireo. 

 (Showing long first primary.) 



Blue-headed Vireo. 

 (Showing short first primary.) 



