Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your situation, and wanted to help.
First, this does sound like you have a male mallard.
Second, I agree that this lad needs to live a duck's life (even if he cannot be released back into the wild). And I have to say that to do so, he'd be best with a rehabilitation center that has other ducks. This would be our best middle ground as opposed to remaining a pet or being tossed out at a local pond with other wild ducks. It would allow him to have access to others of his species (in a controlled manner and without having to rush to be able to survive). And this is critical for Jerry since there is no easy way for you to teach him those natural traits he never learned. He needs to see other ducks foraging and swimming (and the benefit of each) to figure out and catch up with his natural developement. So, that would be the best option for his long term life. In regards ***** ***** your local rehabilitation center, you can check:
Wildlife Rehabbers: http://wildliferehabber.com/rehabber-search
NYC Audubon: http://www.nycaudubon.org/animal-hospitals-and-rehabilitation
City Birder: http://citybirder.blogspot.co.uk/p/wildlife-rescuers.html
Please take care & best wishes for Jerry,