This is the way it is supposed to work. My daughter has a gymnastics class in the office park right off the Blue Heron Trail in Needham. So I get an hour to walk in the woods while she's in class.
I walk down the trail, cross the road to get to Nahanton Park in Newton, listen for chickadees, find them, pick up the binoculars, and... pine warbler.
The chickadees must have found something really good, because they were chatting up a storm. The warbler was definitely checking it out. In fact, doing some chickadee-esque acrobatics while bug catching. Probably the best look I've gotten this year. Low light but right out in the open. Thanks, pine warbler!
[UPDATE: My colorblindness makes me wonder: is this actually a blackpoll?]