CHESTNUT-SIDED WARBLER 117 



migration of warblers. It passes north in the middle of 

 May and returns in September. It breeds commonly on the 

 high mountains of northern New England and in the exten- 

 sive coniferous forests of northern and eastern Maine. The 

 song of the Bay-breast suggests somewhat that of the Black 

 and White Warbler, or the short form of the Redstart's 

 song. 



This is the only warbler that has a chestnut crown, throat, 

 breast, and sides ; the Yellow Redpoll has a chestnut crown 

 and slight streaking of chestnut on its yellow under parts ; 

 the Chestnut-side has a narrow stripe of chestnut along the 

 sides, but a yellow crown and a white throat. In Septem- 

 ber a few Bay-breasts pass through eastern Massachusetts, 

 and a larger number through the Hudson Valley. They 

 now resemble the immature Black-poll Warblers so closely 

 that only a trained eye can distinguish them. The buffy 

 tinge over the under parts, the buffy under tail-coverts, 

 and occasionally the tinge of reddish-brown along the sides 

 are their distinguishing marks. 



Chestnut-sided Warbler. Dendroica pensylvanica- 

 5.14 



Ad. $ . — Top of head yellow ; back in strong light of a green- 

 ish tinge, streaked with black ; wing-bars yellowish ; cheeks 

 white ; sides of throat black ; a narrow stripe of chestnut-red 

 along the sides of breast and belly. Ad. 9 • — Similar, but duller. 

 Im. — Entire upper parts yellowish-green ; wing-bars yellowish ; 

 under parts white. 



Nest, in a low, slight bush, often a blackberry or a raspberry. 

 Eggs, white, speckled, chiefly about the larger end, with reddish- 

 brown. 



The Chestnut-sided Warbler is a common summer resi- 

 dent of ]STew York and Xew England, but is less common 

 in the lower Hudson Valley than farther north. It arrives 

 early in May and stays till the end of September. It pre- 

 fers dry roadside thickets or clearings, and though its song 



