Lots of good information here but being the proud (and often ticked off) steward of muscovy, I do have to warn that muscovy are very unlike most other ducks you'll read about. They're incredibly smart, more stubborn than an old mule, and though large bodied, able fly really, really well. They're not all that skittish or flighty, make top-notch mothers and even enjoy perching if they have the option available. They don't quack but instead making chirping and whomping sounds, often sounding like someone coughing, but are overall usually so quiet that someone could easily miss the fact that they're around.
As for flying, our girls often do loops around the lower part of our property, around 30ft in the air and circling over 1/2 an
acre at a time before making a perfect landing on the roof or splashing down in a pond. In fact, over the winter months, they had decided the roof was just plain awesome and spent all their outdoor time up there where the snow was shallow and sun was strong. The fact that the wind was also strong didn't seem to bother them any - feathers ruffling in the -5*F windchills, they'd sit up there for hours at a time sunning themselves.
You pretty much have to cut every single feather on their wings to "ground" these birds, and even that doesn't quite do the trick. Drakes aren't as bad simply because they get so heavy that all the flying takes too much
energy, but they too can really surprise you sometimes with flight capability. They're like flying gallon wine jugs when they get going, usually no more than 5-7ft off the ground, and god help you if you get in the way
Gardens (especially heavily mulched gardens), and this one might even apply to all ducks, are a highly prized location for the trampling around in search of buried slugs and seeds. They absolutely love to completely strip the mulch from the soil, creating piles of the mulch outside the garden as they go. Thankfully, this is mostly a spring chore for them as they search out all the slugs buried down there overwintering. Sunflowers, beans, peas and squash are their preferred
seed thefts right now, but they're also good at rooting out just about any brassica or chard/beet seed, adore lettuce seedlings, and will at least try just about anything else you might think to plant from seed. As for transplants, if nibbling it a little doesn't give them enough of a thrill to bother with devouring the whole plant, they'll just trample it into non-existence instead. It's as thought they're trying to stomp out the non-tasty plants so only the tasty ones grow. They're often more stubborn than they are smart, however, and even after being chased out of an area dozens of times in a single day will keep returning to it to continue their mission.
Without plenty of training, fences don't mean a darn thing to them because they can easily fly over or even climb. I had to not only fence around gardens to keep them out but also fence *over* the top - this makes it trickier for them to sneak in and do damage, but they often find ways (literally trampling the fence down, finding a hole to sneak through at ground level, digging a hole if they can't find one, or even tearing right through if the fencing isn't strong enough). Once, I caught two of the girls actually digging around a fence post with their bills in what I can only imagine was an attempt to take it down!
And oh they are stubborn. Stubborn to the point of driving a person mad at times. Our girls decided to try laying eggs in our
greenhouse garden last year. It was like going up against a chess grandmaster trying to figure ways to keep them out of there - they found every single weakness in our "system" in their persistent attempts to lay eggs in there, going so far as to claw their way through the 2 layers of 6 mil plastic at one point. It was a team effort with 4 ducks participating - each morning we'd do battle with at least two of these 4 as they poked and prodded, testing every inch of the structure, chasing them away only to have them return moments later trying to get in again. We eventually won that battle, but really, it could have gone either way there for a while.
All this said, I love our ducks - they're incredible! They're smart, curious creatures that often look at you with an understanding in their eyes beyond that of even half the "humans" out there. They'll often crowd around watching as I'm out building structures or digging new ponds and gardens, quietly chirping amongst themselves as if discussing what I'm up to today. Their eggs are enormous, creamy, wonderfully flavorful and have nice hard shells that make them difficult to break accidentally. They make fierce and dedicated mothers when allowed to that will defend their nests and young at all costs. They handle the cold way better than even I can and produce copious amounts of what can only be called magic fertilizer mulch. They're smart enough to put themselves "away" as the sun sets if you let them and both agile enough, and imposing enough, to fend for themselves when it comes to many predators. And yes, roast beef is a good way to describe the meat - very lean and bordering on outright "tough" if you don't get them young enough, but unmistakably beefy.
Very different from other duck breeds.