I have 1 male runner (Donald) and 2 female runner ducks Daisy and Daphne. The females both started sitting so I left the eggs to see what would happen. To cut a long story short only one hatched. I call it little Lucy, hatched 15th May. Up until yesterday Donald accepted and protected little Lucy but now he’s started to attack it. Little Lucy has changed colour from yellow to white but as yet I haven’t determined the sex. Could Donald already know the chick is male and that is why he has started to attack it or is there any other reason. Usually I free range all my poultry but because the ducks all getting along so well and the duckling can’t be free ranged until 8 weeks ive left them all in the pen together. Please advise. Ps I have now taken Donald out of the Duck side of the pen and put him in with the chickens for the moment