A family of swans live in our lake....male, female, and five young swans that were born this spring. One of the young swans was most likely bit in the head by a snapping turtle while feeding. The family left it alone. We rescued the near death swan. Brought it to shore where we surrounded it with a wire cage to protect it from harms way. After one day of rest and coaxing to drink lake water with seaweed, its family showed up by shore and the injured swan stood up and followed its family in the water. All seemed well for a few minutes when we saw that the male (father) started snappy at the injured swan to make it leave the family unit. The injured swan is now a lone in the lake. Question: Why did the family not welcome the injured swan back into its fold?