JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 655 



318. Dendroica striata (FORST.). 

 BLACK-POLL WARBLER. 



Distr.: Whole of North America, except west of the Rocky 

 Mountains south of British Columbia; breeds from the southern 

 British Provinces and northern New England northward to northern 

 Ungava and northern Alaska; south in winter to W T est Indies and 

 South America. 



Adult male: Crown, black; nape streaked black and white; 

 auricular region, white; back and rump, grayish ashy, streaked with 



black; under parts, white, the sides of 

 breast and belly streaked with black; 

 two white wing bars formed by the 

 middle and greater wing coverts being 

 tipped with white ; inner webs of outer 

 tail feathers with patch of white near 

 the tips. 



Adult female: Upper parts, dull 

 olive green, the crown and back 

 streaked with black; under parts, white, more or less faintly washed 

 with pale yellow; sides streaked with black; wings and tail as in the 

 male. 



Immature in fall: Upper plumage, dull olive green, the back with 

 obscure black streaks; under parts washed with pale olive yellow, 

 whitening on the belly; the sides of breast usually with obscure 

 streaks; sides of body and flanks tinged with pale olive yellow (not 

 buffy as in castanea) ; wings and tail as in the adult. 



Immature birds of this species and Bay-breasted Warbler are very 

 similar and at times difficult to distinguish with certainty, but the 

 latter usually has a distinct buffy tinge on the flanks, and the obscure 

 streaks on the sides of the breast are absent in that species. 



Length, about 5.50; wing, about 2.90; tail, 2.15; bill, .38. 

 A common migrant in Illinois and Wisconsin in spring and fall, 

 arriving on its northern migration early in May and passing south 

 again in September. The song is a clear trilling whistle, but like 

 several others of our species they often utter a clear and occasion- 

 ally often repeated chip. 



