[header] How to treat feather picking in african grey parrots [title] Take your parrot to the vet. [step] If your bird is ill or in pain, then it may pick its feathers to cope. Birds don't understand how illness or pain work, so their instinct tells them to try to remove the cause of what's bothering them, which leads to plucking. 
The plucking can also be caused by hormones, which can be treated by the vet. [substeps] The vet can check for bacterial infections, parasites, and heavy metal poisoning.