[T]he Least Flycatcher is one of the smallest and most common flycatchers in North America: www.allaboutbirds.org/guide/Least_Flycatcher/id
I've spent three days trying to photograph this flycatcher, in a flock of goldfinches along a section of the Brandywine because, when I first saw it I immediately thought it was different than the Willows I've been photographing all season. It was very small and the undersides very white and the wingbars well defined and something about it...was different. In the photo however, its distinctive elements are not so apparent . Still, I'm going to stick my neck out and say Least Flycatcher. According to Cornell, the Leasts are very common and "common" is a descriptor of many of my "firsts," another reason to suspect it's a Least.
However, if any of you wonderful people can positively id it as a Willow, please feel free to do so. (And watch your back from now on :-)
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