How long ago did you see these guys? Not sure if they're just inbreds from the wild population or what, but its very possible that they could be dumped. If these are the only ones you saw, they might be sitting ducks. Easy catch for an areal predator.
Edit to add: I believe your boys are some kind of mixed duck. Unlikely that you have a goose/duck cross, and if I remember correctly I'm pretty sure that its not possible for ducks and geese to produce offspring. Could be wrong though.
Glad you can keep them! Good on you for finding those eggs!