How old is he? Mine occasionally try to pull that kind of stunt when they've just noticed their hormones . . . and when I inform them to please stop, that's the end of it. If he's under/about a year or so, I wouldn't worry about it very much. He'll grow out of it if you teach him not to.
None of mine have ever been vicious when they've gotten older, but it should be possible to stop an older drake's bad behavior, too. But let me tell you how I deal with this.
Ducklings big enough to cause bruises: While it's chomping on you, grab its bill. Grabbing just the top part will keep you from getting bitten. Or you can grab the bottom of his mouth and hold on - it'll stop once it's uncomfortable and try to pull away. Hold on for a minute until it calms down. You're not hurting it - just teaching it that biting can result in something it doesn't like. My babies never get scared and run away when I have to do this - it's awkward for them, but not cruelty. Their own siblings will pull out feathers. Grabbing their bills just gives them something to think about.
Adolescent drakes with hormonal problems: They usually go for my shoes, claws and all. I pick them up by their necks and put them down a few feet away, still holding on. Once the hormonal cloud around their judgement is gone, I let them go and they don't bother me again.
Okay, now before I go on to dealing with adult birds, let me mention a little something about birds. Have you ever seen two adult birds fight? It's upsetting to watch, but it's
perfectly natural, and when there's plenty of space,
the losing duck does not get injured (unlike pecking birds, which are a whole different ballgame). The winner sits on top of the loser, sticks his bill in those back feathers, and pulls at them for a minute. Then the losing bird leaves. I've seen this thousands of times, from both my ducks and geese, and
that's how ducks learn. Now, since ducks establish dominance by pulling at feathers for a minute, I think this is something to take note of. You don't want to ever hurt a bird, but you do want to find a way that the bird will actually
understand what you're trying to teach it.
I would never pluck feathers from any bird. But I do recognize that this is a way that ducks naturally communicate with each other. Therefore, here is my advice on dealing with a problematic bird:
Adult duck: Pick it up. Waterfowl will not be harmed if they are picked up by their necks - or anything you can get at, really. Your safety is more important - pick the bird up by its neck and move it away from your body. Then put it on the ground. Hold its head to the ground (this will prevent scratching and will not hurt your bird. It's also what the dominant bird does to the losing bird, so it will help the lesson you're trying to teach your bird). Give it a bit of time to calm down. Then use your other hand to ruffle the feathers at the base of its neck (again, this is natural for birds and you do not need to pull feathers). Stay there for at least a minute, still with your hand in its feathers. Then let the bird go. If it comes at you again, repeat the process. (If you need to get your point across more effectively, you can hold the bird in the air for longer and ruffle his feathers a bit harder.)
Birds respect each other, and it's not fair to birds when people try to hold them to human standards. Talking to a bird in its own language is how it will learn best - and I promise, none of this will hurt or even traumatize your bird.
My ducks are perfectly behaved. The few that have needed a talking-to have never continued their aggressive behavior.
Best of luck to you! I'm sure your Muscovy will settle down soon.
Oh, and if anyone reading this has had problems with aggressive geese, this applies to them, too. Mine are very polite - but only to people who know how to properly deal with aggressive birds.
And let me say that I
love my Muscovies, and I could never bear to hurt them. I think they love me, too, but then again, I do feed them and spoil them.
<3
