Normal Vocalization. Very loud singing, chirping or squawking at sunrise and sunset are normal types of vocalization. Listen to the wild birds outside. This is when they are the most vocal and active, as  flocks are gathering to forage food in the morning and  gathering  to roost in the evening. Our pet birds are no different and they will vocalize at sunrise and sunset as well.  Birds in the wild will also call out to each other throughout the day to keep in contact with other members of the flock so they are not abandoned. This is known as flock calling. Our pet birds will flock call, to keep in touch with their human flock members as well. If you leave the room , your bird may scream trying to locate you. This is normal. Your bird needs reassurance that he/she has not been abandoned by you. Calling back to your bird from where you are and establishing a flock call, (a specific word or whistle to repeat whenever your bird screams when you're out of his sight) will reassure your bird that you have not abandoned him. A simple wolf whistle or a phrase like "YooHoo, YooHoo", once recognized by your bird, is usually enough to stop the screaming.

Other Causes of Screaming: Birds in the wild also scream when they are frightened or when they  perceive danger. The purpose of the "alarm call" is to warn other flock members of that danger.  It's an instinctive behavior and one necessary for survival. If your pet bird is frightened by a stranger, an intruder or a perceived danger in your home, it's normal for him to scream too. You may have already noticed that your cockatiel is a  very effective "watch bird", screaming when he hears you coming home from work or when he hears the mail carrier approaching your front door.  Birds are tiny animals compared to other objects and creatures in the environment so they are always on high alert for predators. From a bird's perspective, the new picture hanging on the wall or the new, colorful toy or rope perch you put inside the cage can seem like big, frightening, bird eating monsters. 

A cockatiel that feels threatened or frightened will scream. Cockatiels are afraid of the sudden movements of small animals or children, deep voices, humans screaming or yelling, the high pitched voices of some toddlers, loud music or televisions, slamming doors, barking dogs, thunder, fireworks, firecrackers, the sounds of outdoor workers near the home, the sound of the wind and wild birds. Any of these factors can cause a cockatiel to scream. There are other causes besides fear, that will spark an episode of screaming. Pet birds exhibit problematic vocalization in homes that are, hectic, chaotic or overly energetic.  Cockatiels that are  hormonal during longer hours of daylight in Spring and Summer, birds that are bored or never taken out of the cage, birds that are  overly excited, cranky, not feeling well, tired from not getting enough sleep at night (10-12 hours), birds that have had a change in their environment or routine, grieving birds who have lost a cage mate and single birds who are left home alone all day may also scream. In all of these situations, a certain amount of screaming is to be expected and it's normal. 

Reinforcing Screaming Although screaming is a part of owning a parrot and a flock behavior, it's not normal for a pet bird to be screaming all day. If 1 cockatiel screams, it's more than likely that your other cockatiels will learn how to scream too. Screaming becomes a behavior problem when a parrot learns to scream excessively for attention. Our reaction to excessive vocalization will determine whether or not this behavior becomes a habitual problem. Birds who are considered screamers have in some way been rewarded for this behavior, even though their reason for screaming is rational from a bird's perspective. It's up to us to identify what has caused screaming in the first place and to either eliminate the source if possible, or to slowly  desensitize the bird to the source. We must then identify what we have been doing to reward and reinforce screaming. If screaming is being caused by seeing wild birds outdoors, move the cage away from the window. If a barking dog in the bird's room causes screaming, don't let the dog in the bird room. 

Most avian behavior consultants agree that negative behavior like screaming should always be ignored and positive behavior, like being quiet, playing, doing tricks, talking or singing, should be rewarded. However, we often do the exact opposite of what we should be doing by encouraging and rewarding screaming.  It's common for even the most dedicated and loving cockatiel owner to ignore a bird when the bird is quietly playing then reacting with strong emotion and drama when a negative behavior like screaming is exhibited. Your bird perceives any type of reaction to screaming as attention and a reward. If your bird screams and you come rushing into the room or go up to his cage or he if he screams and you yell at him to simmer down and be quiet,  you are giving him the attention he wants, You are reinforcing the behavior. It doesn't matter if it's negative or positive attention, it's still attention. 

Solutions: It's much easier to prevent screaming than it is to deprogram a bird and stop screaming once it becomes a habit and a constant call for attention. It takes a great deal of patience to stop screaming but it can be done. Avian Behavior Consultant Liz Wilson states that it takes about 10 days to eliminate an undesirable sound, like an annoying word, from a bird's repertoire, and you do this by ignoring the word. Getting a bird to stop screaming can take much longer. The habit did not develop overnight it's not surprising if it takes just as long to undo the behavior that we reinforced for so many months. There's also a pretty good chance that the screaming will get louder and longer at first. Have patience and be firm. Ignore the screaming and do not show any reaction to it at all.

• Do not reward screams. Whenever you rush over to your bird in response to a scream, you are teaching your bird that screaming gets the results he wants.
• Establish a flock call so your bird can keep in contact with you when you leave the room. Choose a word or whistle that your bird recognizes to let your bird know you're home.
• Use your flock call when you leave the room so your bird knows where you are.
• Yelling, punishing, responding with anger, banging on the cage bars or any other negative responses will damage the trust your bird has in you. It also teaches your bird that screaming gets desirable results.
• Make vocal  contact with your bird first, before he has a chance to scream for you.
• Ignore the screaming and only give your bird attention when he is quiet.
• Walk out of the room and don't come back until your bird stops screaming.
• Reward and praise your bird for good behavior like playing with toys or making pleasant sounds like chirping, talking or whistling.
• Lower your energy level. If you are prone to talking or moving  quickly and you show excitement in your voice, use a more quiet, slower and calmer voice tone.
• Keep the cage away from doors and put it up against a wall, near a corner for security.
• Keep the back of the cage covered so your bird has a place to retreat when frightened.
• When your bird is hormonal, during Spring and Summer, cover the cage for 14 hours each night for 2 weeks to break the hormonal cycle.
• If your bird always screams when you have company, move his cage into another room where he will be more comfortable, before your guests arrive.
• If you know your bird screams when you are cooking, walking the dog, watering the garden or on the telephone, distract him with some millet seed or a favorite toy before you start.
• Although not always effective and as a last resort, covering the cage may help to calm a bird that has been over stimulated by noisy children, barking dogs or outside noises. Take the cover off when your bird is quiet.
• Take your bird out of the cage several times a day when he's quiet, not when he starts screaming, to break up boredom and give him the attention he needs.. 
• Put your bird on a play gym when you are in another room folding laundry, paying bills, reading etc. This gives your bird extra out of cage time.
• Keep a supply of colorful, interesting  shreddable and movable toys in the cage and rotate them every week to keep your bird busy.

Exceptions: Sometimes screaming should not be ignored. If your cockatiel's cage has been pounced on by a dog or if he has just been frightened by your neighbor shooting off a package of bottle rockets, it's necessary and appropriate for you to go over to your bird and reassure him that he's safe. Screaming to greet you when you come home from work is another exception. If you use your flock call then go over to the cage and say hello to your bird when you come home each day, you can prevent screaming from becoming habitual. Birds who have lost a mate also need reassurance so it's appropriate for you to spend more time with them as well. If your bird's screaming seems to be completely devoid of meaning, it's a good idea to walk near the cage without maintaining eye contact or speaking, and check to make sure that your bird is OK. The scream may be from having a toe caught in a toy, or you may have forgotten to replace the water dish this morning or a mouse or fly may have taken up residence in the cage. You may also want to consider taking your bird to an avian vet for a check up to rule out pain caused by a health problems.