Realistically, they are wild animals that are hatched domestically by hatcheries. They are not domestic in the sense that they have been domesticated by humans. It would be like calling a tiger a domesticated animal if fed by the zoo. It might be raised at a zoo, but it is not a domesticated animal. They will probably fly away eventually. I called a few hatcheries that sell true mallards and I was told they will fly away if you don't clip their wings. I don't plan to because its cruel and usual to harm them. There are mallards around where I live (in fact 7 minute walk away). That's why the person thought it was a good place to put them. There is no need to release them anywhere nor do I plan to. I actually like them.
If you go on Wikipedia and look at Mallards or more credible websites, the very definition of a mallard is a wild duck. Domesticated animals are the result of domestication. It hasn't been domesticated.
To make you sleep easier, I don't plan to release it anyways. They are only interested in seeing me when I have foods. A few month later, they will probably fly away.
I think the source that I gave out anyways clearly indicated it is not illegal to release it if its not a domesticated duck. If you check what counts as a domesticated duck, you will not find mallards on the list. There are cases where people have raised orphaned mallard ducklings and released them. I have not heard of them being fined or drag to court. If raising orphaned ducklings or saving abandoned eggs means heavy fines and jail time, I am pretty sure this will be all over the front page of the New York Times and every other major newspaper by now. To the best of my understanding, this has not occurred. There hasn't been any precedent concerning this aspect in relating to mallard. If anyone can find a case like it, I would be very thankful as would hundreds if not tens of thousands of other people. In Florida, it specifically stated (recently in the last decade) that releasing Mallards are illegal because it destroyed the native black duck's habit. I have yet to see anything remotely similar or a case similar to Florida's in other states.
Also, in terms of survival. If you read the study (too long for my attention span), I didn't read the whole thing, but I skimmed it. They said they were released when it was 2 weeks old. At two weeks old, it can't even fly at 2 weeks! They also released over 100 per test group. If you were a bird trapped with 100 other bird for 2 weeks probably in a small area for the experiment, I can not imagine you would want to return back to the people that kept them there. I think that partially explains the low rate. In theory, they are genetically as fit as the wild ones. I can't imagine them not wanting to migrate to escape it. Especially since the researchers stated specifically they introduced diversity and prevented inbreeding. I think too many birds flew away and never came back I think thats why the results were much poorer. If they treated them nicer, I bet it would be higher for returning ones. I will read the whole study tomorrow when I am not exhausted.
I am not releasing any birds. They are already moving further and further away, but still come back at night. I still feed them fruits and leafy vegetables, but they are starting to eat grass and other plants. I think this topic gets too emotional for too many people. Until I see mallard classified as domestic animals or livestock or that seeing people dragged to court for releasing abandoned ducklings or saving eggs, I am not buying this you will be dragged to court for this and be locked up in jail smoke and mirror stuff. If the wild game officers didn't stop factory farming, I can't imagine they would hunt down people releasing genetically wild ducks identical to other mallards while other people dump actual domestic ducks into waterways and ponds. I know some people might feel offended, but let's just let this topic end. No one is releasing any ducks and there hasn't been any precedent for people locked up for releasing domestically raised wild mallards. I can't even find people who were fined or charged under the so called "animal cruelty law" [It would really be stretching it] for it. Like I said, the only state that said it is illegal is Florida and you don't even find cases of strict enforcement of it. Never mind the states that doesn't even have something like it.