I'm sorry that your question wasn't answered in a timely manner. We don't have many avian vets on this site. The following was exerpted from three main sources: Gallerstein, G. The Complete Bird Owner's Handbook. Howell Book House. New York, NY; 1994.Spadafori, G; Speer, B. Birds for Dummies. EDG Books Worldwide. Foster City, CA; 1999.Wilson, L. Proceedings of the Western Veterinary Conference; 2001. Screaming parrots are all too common. Please review the following and then return to our conversation with further questions or concerns. Birds are noisy animals. When communicating to their flock, they need to be loud in order to be heard.Some species will celebrate the sunrise and sunset with squawking or singing; pet birds do the same.Other species, whether in the wild or as part of a human family, will make window-shattering sounds throughout the day or vocalize several times a day for 20 minutes at a time.Wild birds use vocalization to warn others in the group about impending danger, such as a predator in the area. If a pet bird is afraid, she will do the same thing.Birds who find themselves away from the flock call to the group and find their way back when the group answers. Your parrot may produce short sounds with pauses in between, and is simply saying, "Are you there?"Such means of vocalizing to communicate are normal. It is not normal, however, for a parrot to scream in the same pattern for lengthy periods of time. This is not a happy bird. Screaming by unhappy birds can usually be traced back to an underlying problem that is stressing the bird. These stresses include:Illness, including nutritional problems from a poor diet**, which may cause the bird to change the amount of vocalization or other behavior. Rule out a possible illness by having your bird examined by a veterinarian. Please see here: www.aav.org/A change in the family makeup, such as a new family member or the loss of a family member (e.g., death, gone away to college).Loneliness or boredom, which often occurs if there is a change of routine (e.g., vacations, longer work day, holiday bustle).A change in the environment, such as a move to a new home.Fear, which can cause a bird to scream just as she would in the wild.Jealousy, resulting from the addition of another pet or paying more attention to certain individuals in the house.Inadequate sleep due to cage location, household noise (e.g., TV), too much light, or people moving around the house. Please note that some screaming is normal behavior for a parrot. Your goal shouldn't be to eliminate all screaming and loud squawking, but to reduce the screaming to a tolerable level. This will require gentle patience and consistency among all family members.Start to rehabilitate the parrot by making sure her basic needs are being met, reestablish the humans as higher ranking (e.g., step up and step-down training), and keep a diary of all screaming episodes. In the diary, record all the information about the episode including but not limited to time of day, day of the week, phase of the moon, what is happening at the time, and the moods of the people and the bird before, during, and after the episode. With this information, hopefully, the cause of the screaming can be identified and eliminated.The two questions which must be considered when trying to rehabilitate the parrot are "What should I do when Daisy screams?" and "What should I do when Daisy is behaving properly?"When Daisy is misbehaving, you don't want to inadvertently reinforce the behavior, for this can make the behavior problem worse. From Daisy's perspective, getting any attention while she is screaming may be a reward. Some parrots may actually like you to yell back since they love drama and the yelling becomes a reward. Yelling, hitting Daisy or the cage, leaving her isolated, spraying her with water, or withholding food will only increase the stress on a bird and either make the screaming worse, or a bird will turn to another unacceptable behavior such as feather picking/plucking.The best way to improve Daisy's behavior is to give positive reinforcement, i.e., giving something good to her when she behaves correctly (e.g., sitting quietly on a perch). This could be a special toy, a food treat, and verbal praise. These are rewards and not to be used to bribe Daisy into better behavior.If she's exhibiting a bad behavior in a certain circumstance, it is important to determine what it is that you want her to do instead. Then you can teach her to substitute the desired behavior for the undesired one. For instance, teach Daisy to talk instead of scream. Then reward the desired talking behavior. Consistency is absolutely necessary; reward the good and desired behavior and don't reward, in any way, bad behavior.Some bird experts suggest that if the bird continues to scream, give the bird a dirty look, cover the cage, or leave the room, returning when the parrot exhibits an acceptable behavior. Others suggest that this may actually worsen the problem, especially with birds who are screaming out of fear. This is why understanding why she is screaming is important. You can adjust your actions depending on the circumstances.If she's screaming due to loneliness, you may need to think of other solutions. If the bird has a reason to be lonely because the owners can not give her sufficient attention, it may be helpful to get another bird for companionship. The new bird does not necessarily have to be a mate, and could even be kept in a separate cage. Think first, though. If you, the owner, do not have time for one bird, are you going to have time for two? Is it fair to the birds? You may want to seriously consider finding a new home for your bird until your life style changes and is better suited towards having a pet.For many birds, an alternative outlet for the bird's energy needs to be provided. Exercise on play gyms, flapping sessions in the shower, supervising the bird while you take her outside, or leaving the television or radio on can all help relieve pent-up energy. Don't turn on nature shows on the television, though, as they may scare a bird into thinking a predator is in the room. Old phone books, natural, non-toxic tree branches with leaves, and paper cups can be given to the parrot to play with (and destroy). Use foraging toys to hide her food, so she has to work to get it. This gives much-needed mental stimulation, and provides a way of feeding that more closely resembles what a bird would do in the wild. Short daily training sessions should begin ideally from the first day the bird is brought home. Parrots respond to facial expressions and verbal praise. This type of positive reinforcement should be used when an appropriate response is given by the bird and no response should be given for incorrect responses. No aggression or punishment is involved in the training. The daily lessons need to continue until the bird responds willingly to the commands. Once the commands are followed, discontinue the training but continue to use the commands during the daily handling of the bird.Remember, parrots use vocalizations as warnings and as ways to find the rest of the flock when separated from it. Screaming can often be prevented from starting by simply answering the parrot when she calls to you, and letting the bird know when you are leaving and have returned. The screaming behaviors of parrots can often be resolved or minimized. This may take time and help from an experienced avian behaviorist (please see here: www.dacvb.com), but if it allows the bird to stay in the house, it is worth it. ** Seeds should compose less than 20% of her diet. Ideally, a balanced pelleted diet such as can be found here: www.harrisonsbirdfoods.com or here: www.lafeber.com/pet-birds should be fed as well as hard boiled egg yolk, pancakes and cornbread, the tops of fresh greens, dairy products such as yogurt and cheese, fresh fruits such as apples, pears, melon, kiwi, and berries, vegetables such as broccoli, carrots, beets, asparagus, cabbage, sweet potato, and squash, and even tiny pieces of meat.