That information helps a lot! She hasn’t laid eggs too often, or too young, so that isn’t the issue. I think the main issue is that you handle her, and try to handle him. It helps to understand wild parrot behavior. Young parrots interact with flock members, and engage in some mutual grooming – but stick to the head & neck mostly. Which is why we recommend the same for owners when petting your bird. Once a parrot is old enough to bond with a mate, the physical contact with flock members pretty much ends. Pairs keep more to themselves within the flock, and other flock members who get too close will be reprimanded, generally by the male. And once breeding season starts, the pairs distance themselves from the flock and establish a nest and territory. They are less tolerant of any others being too close. If a rival approaches, and won’t back off, the males have been known to turn on the female, to force her back into the nest. I suspect this is what sparked your male’s attack on the female. And it’s also why he is more likely to bite you. When our pet birds bond, it creates confusion when we continue to want to handle them.
Reading back, you never said if you were trying to breed them and if they have a nest box. I think no? But if yes, then you need to really distance yourself from both birds during nesting. Otherwise, if not interested in breeding them, then when you notice signs of hormones in either bird, make the changes I recommended. If she lays eggs, keep him separate, to avoid any outbursts. As they get older, the hormones seem to get stronger. In fact Dr. Lamb was talking about how some senior birds suddenly lay eggs for the first time, or the males suddenly get really hormonal – maybe nature’s last effort to pass down the genes. Since they each have a cage, and you can move them around, I think now that you know he might do this, you can better predict when he is likely to have another jealous rage. I think he was either reprimanding her for paying attention to you, or just trying to keep her away from you. And it’s probably more of an urge that he doesn’t fully understand, so he gets frustrated and takes it out on the nearest living being, which was her at the time.
Thanks for the update!