Hi M.L.
We have not seen anything in literature regarding this issue, but that doesn’t mean that it does not exist. We just have not seen it. Yes, there are several reasons for this behavior:
The male has already been in a scuffle, lost the battle and is extremely frightened and avoiding another fight. He could been injured and trying to recover before engaging in a future battle. There is also one other reason that could be in play. During the summer months, usually in July, but could be later, swans moult. This means old feathers drop out and new feathers are grown. At the time of moult, the birds cannot fly. Each parent will moult at a different time so that at least one parent can fight and fly to escape if necessary. This might be the behavior you are seeing. Once the male’s feathers are ready for flight, you may see him engaging with the other male. On another note, most male swans (and most animals) may significantly injure or even possibly kill another male, but they usually do not try to injure a female. Although this can happen, it may be by accident as the male is larger. Remember the old adage, “a man should not hit a woman”, even applies in the wild because a female is more valuable to increase the flock/herd as she can mate with another member if something happens to her mate and she can be taken as a mate by a stronger rival member.
Male swans can also severely injure smaller cygnets that get in the way if a scuffle occurs or they enter someone else’s territory. This why one parent must always be able to fight and protect their young. We hope this information is of benefit. The Regal Swan