Bluejays are very common around here, and they enthusiastically go after the sunflower seeds and especially the peanuts we feed them.
I noticed one bluejay tilting his head and looking very uncomfortable as he struggled to pick up a peanut. Looking closer, I saw that he had no top beak! Yikes! How can he even feed himself? He looks just as plump and healthy as the others, but he sure has trouble picking up peanuts. He chases them all over the table. We put down a tea towel and shelled some nuts so that it would be easier, but he seems pretty self sufficient.
I put out some shelled sunflower seeds, but he didn't like them at all. Spit them all out.
It does not look like an injury. Online you can find pics of overgrown and deformed bluejay bills, but I found none like my guy. Overgrown bills may be due to a virus, and maybe that is the case here too.
Good luck to this guy. We will continue to feed him.