Okay so this female swan just one has been taking care of 20 we counted the 20 ducks about a few months old but she hunts for them and feeds them and just why there is only her there we set up cameras to see and here she watches them like crazy they go out on the pond if 1 of us comes she herds them back to her they are mallard ducks we know that and she is a mute swan

Can you pls answer why she would do this THX