A couple of options:

- separate out groups of 2 to 3 females to house together who will give birth at the same, leaving the male alone.

- feed off the male so you have one more tub to do the above and grow up a male stud from one of the babies.

I tried to keep a 1.2 group together when one of the mommas gave birth. The babies were nommed instantly. Right now, I keep my male is a shoebox size kritter keeper type tub and introduce ladies to him. When they're a few days from giving birth, I move them into their own enclosure to give birth, with one exception when I have 2 preggers in my grow tub. In that case, I fed or froze off the rest of the growers and left the 2 preggers to have birth and raise their young together, which they did fine. I haven't had babies nommed in a while. =)