MA - dull Chestnut-sided Warbler

 

 

Chestnut-sided Warbler - adult female, Prescott Peninsula, New Salem, Franklin Co., MA. June 10th, 2013. Found this bird actively attending a nest with a typically plumaged male Chestnut-sided Warbler. It struck me as being notably dull and pale with only small traces of 'chestnut' on the flanks and at the base of the malar, and thus much closer in overall appearance to many first-winter birds.