I have a Minecraft world in bedrock and I have never tamed a bird and neither has my friend but when I started playing after leaving the window open to let my friends play while I worked and a parrot jumped on my shoulder I dropped it and my other friend walked into it picking it up. We messed around for a while until a third player came and put the bird on a lead taking it off our shoulders at any time. The bird wont follow anyone whether in water, in the air or just standing on the ground. No one can make it sit either.
Leashing and getting on the shoulder isn't limited to the owner.