Welcome and be welcomed. I 100% agree, friend. This guy needs to see what we call a certified avian vet ( definitely not a cat and dog vet). They will know the cause and treatment if there is a medical reason for the feathers, or can suggest somethings if it is not medically involved. Parrots sometimes barber feathers as a result of stress, like biting nails is in humans. Was his prior home a good one? Parrots kept in poor conditions often do this, but Amazons usually do not for some reason. ALl the more reason to have him checked out by a CAV (certified avian vet).