Hi Bob,
Separating them was a good move for now. It depends on whether or not you plan to breed them. If these are meant to be pets, just keep them in separate cages. The male will adjust to the change after some time. Birds will almost always bond with another bird when they share a cage, even if they are the same sex. As to why the male did this, my guess is they are both under 2 years old. Cockatiels should not be caged with the opposite sex until they are old enough. If one becomes mature before the other one, the mature bird will get frustrated and start picking on and then attacking the immature bird. Possibly the male is interested in mating and the female isn’t receptive, so he attacked her. It’s definitely not a good idea to have an immature female with a mature male. Not only are attacks likely, but her hormones can get triggered and she might try to lay eggs at too young of an age. This puts her at a high risk of becoming egg bound and dying. If these birds are too young, but you do want to breed them, then you can try to reintroduce them once they are both 2 years old. If these birds are over 2, then it’s hard to say why the male attacked her. It could still be that he wants to mate and she doesn’t. But in captivity, some cockatiel males seem to short circuit and turn against the hen. Sometimes they do it when they are both already sitting on the eggs – the male will start chasing and attacking the hen and not allow her in the nest box. We don’t know why this happens, but generally it means the male should not be used as a breeder again because once they act this way, they are likely to repeat the behavior.
Thank you for asking Lafeber,
Brenda
