Yes, this is normal behavior. In the animal world, there are alpha males which control the flock or herd. In this case, this alpha male may be so territorial and such a terror that the swans are actually moving away from his territory instead of engaging him which could result in a fight leading to a possible injury or even death. In other words, what you might be seeing is not herding, but running away from a fight. And, yes, this is still normal behavior. The Regal Swan