There's no way to keep them separated. They ducks & chickens have a fence, he's never hurt one (hell, the ducks are bigger than him) but where Mom goes, he goes.
I have a 10 year old schnoodle that HATES* our 6 month old Pekin ducks. (We have 6). He also hates our two year old Teddy Bear Hamster & he hated our 6 previous hens(a weasel got to them, but we are getting more). He can tolerate them, until I have to go in their pen to change water & such. What...