I'm really, really sorry to keep asking questions. It's just that, I can't tell whether the father is being too rough. I don't think he knows how to feed the chick either. He sometimes tries to interrupt the mother and feed it for himself, but it doesn't work - I don't believe he knows how to regurgitate. I also can't tell if he's nipping at the chick, or just trying to move it underneath him. (It's still only the chicks wing that is slightly bruised.) Sometimes I look in and he's sitting on the chick and eggs like normal, but sometimes the chick is on its back or scrambling around a bit, while the father 'pecks' at it or tries to get it underneath him. The mother can feed it perfectly and is gentle, but is usually busy sat on the eggs, leaving him to cover the baby. I just can't tell whether anythings wrong. As I'm here typing, the baby is being fed and is actually stronger than I thought a baby cockatiel would be, and chirping away. But since I've never had a chick before, it's hard to tell if there's an issue.