On 22 January 2016 I awoke to a light snowfall. I estimated it to be about two inches deep when I went out to fill the bird feeder. Returning inside I looked out the window where several Dark-eyed Slate-colored Juncos were at the feeder and on the ground below. One of them, which I had seen before, had a white streak around the nape of the neck but another had an almost completely white head.
He had a dark splotch on the forehead and a dark gray “collar” around the front of his neck. Otherwise, he was marked like a Slate-colored Junco including the white tail bars, slate gray back, and flesh colored bill.
According to David Allen Sibley’s The Sibley Guide to Birds an aberrant plumage such as partial albinism results in some feathers being pure white. “Partial albinism often follows feather groups, so that white spectacles or an entirely white head might appear,” says Sibley.
I saw him once more the next morning but have not seen him since. I will be curious to see if he shows up again in 2017.