Well sounds like a Muscovy's paradise there especially if they are fenced from dogs. But do yours fly? I have to clip the wings on my females we have a mountain river down below us that if they were to fly too most likely I'd never get them back. Oh and don't worry about getting ducklings next year you'll have more than you can imagine if you don't practice birth control they are very similar to cats and kittens they like to produce a lot of ducklings. So you might want to limit the amount of eggs you let your females sit and hatch.