Birds pull out their own feathers for a variety of physical and psychological reasons. First, determine if they are pulling the feathers or not. Is another bird, maybe a parent, driving the bird away by plucking the top of its head? Is the mate dominating it? If the back of the head is missing feathers, the bird is innocent; his beak cannot reach that far!
Once you have decided that your bird is pulling out it’s own feathers, you and your vet need to decide why. Parasites, (mites, Giardia), injury, allergies, PBF virus, are a few possibilities. Birds with mites may lose feathers around the beak from rubbing it. An old skeletal injury may twinge and throb and be a site of feather plucking. Your bird may be allergic. Sometimes allergies are managed with antihistamines.
Stress is a big reason for plucking feathers. It can be due to insufficient sleep, poor diet, a dominant cage mate, fear of other pets or small children, chronic parasite irritation, or a contaminated environment. Typical poor environments include old cages that leach out lead or zinc, second hand smoke exposure, Teflon or other fumes. Once the problem is corrected, the stress may still need treatment with an anti anxiety medication.
Birds also pull feathers when they have stomach cramps. Giardia is a common cause. It is easily diagnosed from fresh feces. Lab tests can be negative and your vet may treat for it anyway. Some birds constantly reinfect themselves with giardia and need continuous treatment and monitoring. Stress weakens the immune system and prevents them from mounting an immune response against the giardia.
Birds scream for many reasons. Screaming is normal happy loud communication among flock members. When you take a bird into your house, you become its entire flock. Some birds happily express themselves in great volumes. If you want or need to have a quiet household this is not the pet for you: it is illogical to try to keep the bird quiet and both of you will be distressed. Either do not get this type of bird or place it in a more appropriate home.
Some screaming is due to distress and loneliness. Initially the new bird is the center of attention, which makes everyone happy! Then there is a change such as a new roommate, new baby, second bird, job change, etc. that takes attention away from the bird. Not knowing why, it will get louder trying to get attention back. This is often met with reprimands from the owner, which is countered with even more noise from the bird. After all, negative attention is better than no attention, and now you are interacting with the bird! The cycle continues. Eventually the bird learns to start screaming as soon as the owner comes home. The owner is upset and reprimands the bird. The bird is distressed, continues screaming and may start pulling feathers. This is a very sad situation for both the bird and the owner and needs to be corrected immediately.
For screaming or plucking or other behavioral problems, take your bird to your avian vet and be patient! X-rays, blood work, lab tests, specialized blood work; sometimes hospitalization and medication trials take time. Maybe coaching sessions to modify both of your behaviors is needed. Don’t despair; your avian vet will be an invaluable resource to you during these trying times.