TIL that the dark-eyed junco, Oregon junco, slate-colored junco, and all the other juncos are all one species, different in coloration but interbreeding freely. So that funny-looking junco-like bird at the feeder was just another junco.
I may forget this and post it again (if I haven't already). One of the perks of age is you get to learn things for the first time over and over again.