We just got a female goose and female duck for our gander and drake and put them in the same pen at night. Pen is plenty large for all 4 but the drake goes nuts and tries to herd both females and it freaks out the gander. The ducks are Muscovy and geese are emblem (not sure of spelling). We kept the drake out last night and things were alot more peaceful in there. They are out during the day and free to roam the property.