I purchased these ducklings as a rescue from a lady that had to move. She said she purchased them from Tractor Supply. They are Approx 2 months old. When I got them, they were white feathered on the wings and yellow body down... I assumed they were Pekins. As the past weeks have gone, thier heads have turned black; and ones tail turns down, while the other up. Their beaks are pink & red. I began thinking they may be Muscovys; but the only black is on thier heads. Anyone have any ideas?