Mites are sometimes a problem for wild birds. When infected they will lose the feathers on their sweet heads and look very freaky. Don't worry they will recover and the feathers will be replaced but it is a shock to see them in this state. Here are a few pictures of the birds I have seen with this malady.
Female Cardinal...taken last Summer at one of my feeders. She also had a deformed beak which added to her freaky appearance. Poor girl she had a BAD case of mites!
A Northern Mocking bird infected.
A full body shot of the Northern Mockingbird. You can see that this mite does not prevent birds from forging or losing their wing feathers.
Peace, Health, Wealth, and Love to ALL!