In late summer and early fall, people frequently ask us about bald birds that they’ve seen. Naturally they wonder, “Why is that bird bald?”
The short answer is no one knows why it’s bald, but this strange sight occurs every year, mostly in Northern Cardinals and Blue Jays. Of course, we can speculate…
Birds molt their feathers throughout the year, and one possible explanation for baldness is that an abnormal molt occurs on some birds, causing them to lose all of their head feathers at once. The birds may be juveniles undergoing their first prebasic molt.
It’s also possible that feather mites or lice may cause baldness. The condition has not been studied closely, but fortunately, new feathers grow in within a few weeks. ~ Bird Watching Daily