Hi Lee,
Some males will do this in captivity. It’s not known why. Generally it is during incubation. In that case, you take out one bird during the day, and let the other sit on the eggs, and then switch them to let the other sit at night. With chicks hatching, it’s not the best time for him to start this aggression. Can you tell if he has fed the chicks? I would probably still try rotating the parents. He might settle down after they are separated once or twice. All you can do is keep trying them both together and see if he does better. If not, you have to keep rotating them. Hopefully each parent will sit on the eggs and chicks and feed the chicks during their shift. I would not try to let the hen do this by herself. It would be too exhausting and she might abandon the eggs and chicks. Whatever happens, once they are finished with this clutch – hopefully resulting in healthy chicks – remove the nest box once the chicks are out and rest the pair for 6 months before you let them breed again. If he does this again, then I would not breed this anymore. Some birds do not make good breeders.
Take care,
Brenda
