Male cardinals "baldheads"? (1 Viewer)

By this time of year in western wis the male cardinals are coming to the feeder without any feathers on their heads. The top of their heads are just skin, which is white. So they have this embarrassed look from being in public without their signature peak of feathers. And I can't get them to wear a baseball cap.
Are they suffering from some pestilence or from fighting with other males?
Jim

I think it's mostly due to head mites which cardinals seem particularly prone to. At least that's what's often said.

Edit:
Actually it appears to be a little more complicated than that. Here's an interesting article on the subject: http://www.farmanddairy.com/columns...tery-of-what-causes-bald-cardinals/15565.html

I saw a red winged blackbird like that too...and was reading that deer are experiencing the same, so must be mites...