It’s not pretty, and it’s not confined to House Finches anymore: a nasty avian conjunctivitis continues to afflict songbirds here in the Northeast and across the continent. It’s sobering to consider that this has infected birds for at least two or three decades. As soon as my son alerted me to one we pulled the feeders down, cleaned them with Chlorox, and resolved to amp up the frequency and thoroughness our cleaning regimen.
Interested in reading more? The Lab of O has an article on how the disease originated and spread, and this article from the NYS DEC has more about the disease as well as recommendations on what to do if finches show up diseased at your feeder, including a thorough cleaning with a bleach solution.