654 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



Nelson gives it as "an abundant migrant" and states that it "breeds 

 sparingly away from the lake." (Birds N. E. 111., 1876, p. 99.) 



In Wisconsin it is a common summer resident. 



The nest is in a bush or small tree, usually less than 6 feet from 

 the ground, and is composed of shreds of bark, rootlets, plant fiber, 

 etc. The eggs are 4 or 5, white or creamy white, marked and spotted 

 with different shades of brown and gray around the larger end, and 

 measure about .67 x .49 inches. 



There is a set of two eggs of this species in the T. H. Douglass 

 collection at Waukegan labelled, "Collected by Thomas H. Douglass, 

 Waukegan, 111., May 13,1874." 



317. Dendroica castanea (WILS.). 



BAY-BREASTED WARBLER. 



Distr.: Eastern North America, north to northern Quebec and 

 Hudson Bay; breeds from northern New England and northern 

 Michigan northward; south in winter to eastern Mexico, Central 

 America, and Colombia, S. A. 



Adult male: Crown, throat, upper breast and sides of body, chest- 

 nut; forehead and sides of head, black; a patch of pale buff on sides 

 of neck; back streaked with black and 

 dull gray; lower breast and belly, buffy 

 whitish ; greater and middle wing cov- 

 erts tipped with white, forming two 

 white wing bars; inner webs of outer 

 tail feathers with white patches at tips. 

 Adult female: Crown, olive green, 

 obscurely streaked or spotted with black 

 and usually showing more or less chest- 

 nut; back similar to the male, but black streaks less pronounced; 

 under parts, buffy white, tinged with pale chestnut on sides of breast 

 and body; wing bars as in the male. 



Immature: Upper parts, olive green, with obscure black streaks 

 on back; under parts, dull whitish, often faintly washed with very 

 pale greenish yellow on breast, but with sides of body and -flanks 

 tinged with pale buff (not whitish or pale olive yellow as in D. striatd) ; 

 wing and tail markings as in the adult. 



Length, 5.50; wing, 2.90; tail, 2.10; bill, .38. 

 This species is common during the migrations in Illinois and Wis- 

 consin in spring and fall. Although it has not as yet been found 

 nesting in northern Wisconsin, it is not unlikely that it does so, as 

 it has been found breeding in northern Michigan. 



