Thanks for all of the responses! To the point of the duck being transgender, I can't really say. The people we got her from said that they got her as an egg laying hen, but she stoped laying, and developed drake feathers, but it's always possible he has always been a male. As for quarantining her, I'm thinking I probably won't. It sounds like the seller has taken good care of his ducks, and he's never had any issue with disease. However, this is the first time I've ever had to deal with this. If this is a terrible idea, and I should quarantine him, somebody please let me know. Thanks!