Quaker parrots are feral here. They shriek in the trees and my one tiel Freddy outscreamed them no question. You could hear him six houses down the street. And he just did it for fun!
Lol, they can get going sometimes, can't they? Fizz really likes to yell at his bell when he's banging it around. It's a mix of screaming, human words, and bell ringing.
My sun conure was the loudest parrot I've had, hands down. But then, they are pretty 'famous' for their volume. At full volume, they can be heard a mile away. Luckily, Larrikin never really screamed to scream, he'd mostly just scream his contact call.
Where do you live that quakers are feral? I know there are colonies of them in New York City and also in Florida, I think.