African grey parrot... i know they speak but...?

are there any NATURAL sounds that they make?
like a nouns when their happy or in danger?
whether so, what are they..? and what are they for/ what do they mean?
If you hear them literally screaming, then that scheme that he is either really angry or scared. Quiet chittering can mean that they are content.
My parrot foot is red. Why?
My African Grey is very quiet, he never scream, he makes other funny sounds like ow, be. do, be do. in a big pitched voice, he also says many other sounds. Doesn't talk much. he wolf whistle. The only time he has growled is one time he was on the floor and I begin to sweep with a broom. Guess he didn't go for that.
Zebra finches please Help?
Answers:    Scared or in danger would be a yelling/squaking- surrounded by a loud enough pitch to wake the dead sometimes! Happy- never hear of a sound for that other than regular whistling, and repeating of sounds. Birds mimick best when they are relaxed and well.
Birds don't hold beanuses?   Do some birds sing surrounded by winter within southern California?   What type of bird make more babies contained by 2 clutches Lutino cockatiel couple or green cheek conure duo?   This is a true story. Can you explain this bird behavior?