That I don't know might be the less dominate ones would get raped by the biggest and most dominant. What you might want to do just in case is to have a plan B where you have more than one pen. I started out with 3 Muscovy drakes that I met in the river below my home, Long story too. Anyway I fell in love, so my dh says if you want ducks go get your own, so off I go bringing home 3 females Muscovy. Well the boys found out I had females and started visiting during the day and going back to the river in late evening. Come to find out fighting was going on now and one of the drakes killed another which left just 2 down at the river and then only one so I brought him home to live with us. I learned alot during that time about Muscovy ducks. Drakes are fierce fighters and will kill maybe not intentionally but it did happen. I have had 4 at one time, Had to keep each one in separate areras of the fenced property to keep the peace. I'm not saying this will happen with your ducks just be prepared for anything when you have these critters.