You've obviously have hatched them yourself. As they are soooo tame! This is why I want to hatch myself. I want to create tame animals and not birds that are just mass produced! It makes it so much nicer for others who want birds as pets. !
I hatched Goosey, but not "Aflack". Goosey was a lone gosling, so when I went to an animal swap, I purchased "Aflack" to be her buddy. "Aflack" was 1 week old and was in a box with nearly 100 other ducklings. He was definitely massed produced, but I purchased him and bonded with him all the same. He's really sweet.
The key to tame birds is lots of contact. I snuggle them up to my neck from day 1.