It all depends on how they hatch and how you raise them....
Poultry, or birds in general, imprint when they are born. They imprint on a species, not a person.... If they see a duck first (like a duck hatching it) it imprints on ducks a s a species. If the bird is brooded by a chicken, it will think it's a chicken... If it is incubated and see's humans first, it will imprint on humans.
But that is not all..... then.....
The individual bird needs to bond to it's individual "parent" whether it's fowl or not. Normally the adult duck or chicken would be taking care of the bird and providing for it. As a human parent, it requires you to constantly be around and caring for your bird. It means holding it as often as possible, feeding it both regular feed and treats, picking it up often, holding it on your lap often. Walking around allowing it to follow you. It also means not being away from it for long periods of time if you can help it. When I had baby ducks (Ming Mei was by herself) I would hire my 10 year old nephew to babysit her. I'd also give her toys/mirrors,feathers etc to help as well. Whenever I left a room, I carried her brooder with me. Out of all my ducks, she is the most heavily imprinted and bonded to me. All of my other ducklings I got in sets of two, but kept them in separate brooders to ensure they would bond to me. They weren't allowed to see each other (or live in the same house/brooder) until they were about 5 weeks old or so. All of the ducks I raised as day olds (Got them from Metzer, who uses incubators) are very loving and good pets. They like to be pet, go for walks, sit on the couch/bed with us, and just over all like our company. I have one duck, Ollie who I did not raise as a baby and her owner did not spend enough time with her, so she's a bit of a snot towards me (But we still love her and attempt to pet her, lol, she's not so bad when she's not molting or broody).
Bonding to a duck/chicken/goose etc from the time they hatch will produce the most loving of people kind of bird. Imprinting and bonding doesn't necessarily mean they will love only one person or act the way a dog woulds. All birds have different personalities. Ming Mei only loves me and tolerates joe aka Duck_feeder, while Moxy (she imprinted on joe) loves every person she comes across, begging to be pet and loved (She even demands love and attention from our vet, lol). Victor is the only duck who enjoys being held like a baby while being snuggled. Norie enjoys standing on a lap with her head shoved into an arm pit. Vinny is a dope who also loves everyone, while Ollie is very weary of everyone and is only nice/listens to Joe.
I will give a little warning... If you spend enough time with your duck for it to bond to you, throwing it outside and never visiting it would be cruel (and you'll lose the bond over time). Sure they can go live outside with the other birds, but you'll have to visit the bird a lot, bring it treats, pet it, pick it up, not chase it, etc.... So you can maintain the bond you develop.