Witnessed this several times - males killing females babies. One male killed 2 babies right in front of me, he just kept going in the nest pulling babies out and killing them one at a time. Even with me trying to chase him away, he would not leave as he was not afraid of me. He also dropped 2 more babies to the ground, one was alive and in good shape the other was barely alive, bloodied up and dying in my hands from the males attack. I agree with IR - just keep an eye on him.