Thank you. Birds have an inborn instinct to preen or groom themselves. This instinct can become exaggerated to produce the symptoms Fernando is showing. Mites are highly unlikely in a bird his age who is housed alone and not exposed to other mite-infested individuals. Optimization of his diet, rest periods and exercise are what you can do for him at home. His diet should be comprised of 80% pellets, 20% vegetables, particularly leafy greens like Swiss chard, spinach, dandelions greens, carrot tops, cilantro, beet greens, collard greens, etc. Yellow and red fresh sweet peppers are often readily accepted and dried chilies are usually a treat. Raw or cooked pumpkin and squash are very good sources of fiber which contributes to intestinal health. Finally 10% or less of the diet may be seeds and nuts.
As mentioned earlier, 12-14 hours in a darkly covered cage in a quiet area in your home is ideal. Increased attention and time spent with him may also be very beneficial in helping to prevent boredom. Natural tree branches from safe trees (you can find lists of safe trees for birds online) in his cage can provide hours of climbing and chewing exercise. Finally a product called "Rescue Remedy" can be added to his drinking water to help settle his nerves and hopefully reduce the urge to pluck. You can buy Rescue Remedy online or from health food stores. One or two drops in a typical water bottle would be the effective dose for him.
While patience is called for in trying to break this self-destructive habit, if after 6 to 8 weeks, you have not seen any improvement, a trip to an avian specialist should be made. You can locate any that might be relatively close to your home by going online to www.aav.org/search. If you should have any further questions, please let me know. Kind regards, *****