I'm not sure how you would be able to tell. The ones that can fly are really small in size but other than that I'm not sure. Treats will help but with them being outside they will be less inclined to come to you. Or at least that's what I've discovered. If they have access to dirt then they...
Your Pekin is crested I see. There's a link on here somewhere about crested ducks. As the crest is a deformity in the skull. Have you read it already? The Cayuga I can't tell its probably still to young. And or welsh harlequin kinda looks like my fawn and white runner did growing up. Does that...
If its a mallard then yes but if its a Rouen then no. Domestic ducks like the ones you listed can't fly. Mallards, Muscovy, and calls are the only ones that can fly. And of course the ornamental ducks can too. If you post a picture of it I could help you to identify it. Do you have any predatory...