A flash of yellow on the suet feeder caught my attention from the study window.
I managed to get the binoculars focused in time to make a mental note of the yellow spot at the base of the tail and the yellow wing patches. I knew I'd seen this bird before (but not at the feeders).
Fortunately, the field marks are pretty clear, and my memory of a yellow-rumped warbler seen on a birding outing was on target.
This fellow was a male, based on his markings -- I didn't manage a photo before he was off, but here's a good look, along with some great information from one of my favorite sites.