Should I Be Concerned? (long)

I was wondering if I should be concerned about the way my mallard duck male is treating my female.

I got four mallard ducklings last summer, kept two and gave the other two to a friend. My ducklings ended up being both female and my friend's ended up being both male. We kept our's separate for awhile, but a few weeks ago I decided to borrow one of her males because he was being very aggressive toward her other male. After a few days I gave him back because he seemed to be favoring one female over another and he was keeping the smaller female from eating and drinking.

I stopped taking the eggs away from both of my girls and they made two nests right next to each other and haven't been leaving them. But sadly early this morning I discovered that some kind of wild animal climbed into the cage and killed my smallest female...leaving the larger one alone.

I was very surprised that the remaining female moved the other female's eggs into her own nest and is sitting on them. I candled all eggs today and have a total of 11 fertilized eggs. When they hatch should I be concerned that the female will kill the ducklings that are not hers? Should I move those eggs to an incubator when time comes closer for them to hatch?

And another question: since the remaining female was going to be by herself, I brought the male back today to give her company. My mom said that she saw him being very rough with her and almost drowning her in the swimming area. Should I be concerned with him? Will he kill my female or will it get better the longer he stays?

Thanks for any help!

 

Well they should all be the same brown/yellow color since they're all mallards so I'm hoping she won't be able to discriminate by color! =]

 

So I should remove the male?

 

Okay I'll move him.

Thanks! =]