I don't see how it could be him plucking since it looks like it is on the top of his head.
Is he in with other birds who could be doing it?
If not, he should see an avian vet to see what is going on. I hope he gets over this soon
U2-Poppy(Poppy lives with her new mommy, Misty now) CAG-Jack, YNA, Bingo, Budgie-Piper, Cockatiel-Sweet Pea Quakers-Harry, Sammy, Wilson ***Zeke (quaker) Twinkle (budgie) forever in our hearts
Hello there, I can tell you it isn't plucking, even severe pluckers can't reach the top of their heads. How long has the spot been there? Is it possible your bird was injured and then the spot started to grow? My advice is to have your quaker examined by an avian vet as soon as you can. Only a veterinarian can give you a correct diagnosis.
I've heard if some pluckers who use their toes to pull out feathers...just wondering, is he demanding scratches on his head all the time? Or any other birds who might groom/pluck him?