Well I am thinking you should try feeding him at least every other day so he has extra besides what he is foraging for. But of course it's up to you. I just know when I met the 3 Muscovy drakes in our mountain river they were always happy for me to bring food down to them. Only problem I can see is in a setting like you have once he gets use to you feeding him he may come across someone who doesn't like Muscovy and if he tries to get friendly he may get hurt. Being on here for so long I have heard some really sad stories of how Ducks and geese are treated by humans. Can you tell I am a worry wort. lol