Been living with muscovies for several years now, and here are my observations -
They hang out where the food and
water is - we
feed, as we haven't done any forage plantings for them. They would probably act differently if we didn't feed them. The females will go somewhat farther to find good nesting spots - they like brush piles, or similar hidden nooks and crannies. Ours nibble on green stuff, and will eat certain plants to the ground, but they seem most interested in leaf piles, I suppose that is where the good creepy-crawlies are. Next year, I am going to experiment with moving the water around - currently, we supply water in those rubber pig feeders, but I want to use a larger trough and move it around, to spread their use out. The adult birds are hefty, and those flat feet can really trample an area. They are really attracted to mud puddles, and will dabble until the water is all gone.
In the condition we provide, the issue is getting them to range further and not stick so close to one spot!
They don't fly far - a full-grown drake hardly ever flies.