I have one malllard duck(male) and 4 females I started to notice that he is only mating with 2 of the 4 and they are losing feathers and running away from him. How do I get him to mate with all of them? I separated the 2 females to give them a break and he doesn’t touch the other two but as soon as I try to put them all together he goes straight to mate with them. How can I fix this? Thanks in advance I’m new here!