We have 3 pairs of ducks. 1 pair of Pekins ,1 pair Cyugas, 1 pair flying Mallards. All are in a common pen, when we are ready to start incubating eggs, how long will we have to isolate the pairs to get pure bred ducklings. I know chickens can stay furtile for up to 14 days after mating. are ducks the same. The Pekin Drake Draco mates with the cyuga hen and the pekin hen and visa versa with the cyuga drake.We have not seen them try do mate the mallard hen, maybe because she can fly better than them. Any sugestions would be helpful. 
