We spotted a bald red winged blackbird in our yard a couple of weeks ago. Apparently this is more common with bluejays and cardinals.
According to the wealth of information on the internet:
For some unknown reason, a few birds lose all their head feathers at once, instead of molting in staggered fashion, like other birds. The head feathers invariably grow back, but it is a bit disconcerting to see these beautiful birds looking so unhandsome.
We haven't seen him in a while. Either the other birds laughed at him and drove him away, or his feathers have returned and he is still visiting us!