I tried again after work this evening to see if I could get some photos of the Blue-winged Warblers that I've heard but had trouble seeing, much less photographing. The location is the Mary Cummings Park in Burlington, which is pretty convenient to work.
The Yellow Warblers were still common and easy to photograph.
And then finally, I managed to spot one nearby as I watched a second fly by. An hour's patience got me several opportunities for photos
And also, one stayed stayed long enough singing on the same branch that I was able to get some video!