Did you know that most all types of birds molt annually? Knowing they replace their feathers each year should alleviate any concern you may have if you see him plucking out single feathers, one at a time. His plucking is probably just part of the process. However, if you see him plucking out more than one feather at a time on a regular basis, this could be a sign of some type of infection which would warrant a trip to the vet. It could be something as simple as poor nutrition, but it could also be something serious that would need to be diagnosed with a blood test. Better safe than sorry with our little furry friends.