I have been free-ranging my Muscovys for a year where my land is a mix of woods and meadow. So far no problem with predators, but I always secure them in the coop at night. They have learned to come to the coop and enclosed run when I call them before dark. I give them a treat that they only get for this behaviour. My neighbour's cat and my ducks have come to a truce so now they pretend the other does not exist. But I have Muscovys - big ducks. Good luck. I remember how nerve wracking it was in the beginning.