He may be bored. Do you keep the tv 9n for him, my birds watch a parrot dvd all day while I’m working. They also have toy buckets with toy pieces, wood, balls etc wrapped individually in paper with the ends twisted for them to forage with, sometime I wrap treats in there also. Lots and lots of toys for him to tear apart and wood to chew up. It is hard once they start plucking it can become a habit. I have one that started plucking last ear and it’s because she is the lowest on the totem pole and doesn’t get enough attention..my other two sometimes bully her away from the table when we’re eating......it’s sad, but I do the best I can in giving her special alone time...😞