Your cockatiel may be screaming because he does not feel well. He could be struggling with nutritional issues, or he might be suffering from an illness.
01.
He is just merely trying to voice his request in his own less-than-subtle way. Birds like routine, so any sudden change in their schedule can throw them for a loop.
02.
Check to see if your cockatiel has his crest up or is bobbing from side to side while he screams.
03.
Is your feathered friend tired of the same old toys? Cockatiels are very smart, and they need lots of stimulation in an enriched environment.
04.
Birds, like people, show significant behavioral changes and health issues when their sleep is disturbed night after night.
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