Yes, the swans could be migrating into your area since it is now migratory season. They are looking for a habitat with a food source.

Our best suggestion would be to take Carl indoors (garage, etc.), for a couple of days. Remove all food from the area (do not feed any swans or ducks). If there is no food, the other swans should leave. Once they are gone, then place Carl back on the pond and give him plenty of food so that he stays around. (We would suggest building a pen for Carl, but during the winter/migratory season, you risk a predator getting to him and killing him, so this is not a real option)

Moving him indoors is the only viable solution even though it comes with some negative possibilities. One is that since Carl is no longer on the pond, the swans may think forget the food, at least we have the pond to ourselves and they hang around. The second negative possibility is that Carl lands up hating being indoors and will no longer want to get near you because he thinks he will be caught and taken indoors.

We're not sure that the first scenario will not happen, nor the second. However, you can eliminate some of Carl's displeasure by giving him lots of attention and food. As long as he knows he is eating and getting extra treats, he may forget that you brought him indoors. You can possibly dissuade the other birds from hanging around by shooing them away and not allowing them to come up on land near your home. If they have no dry resting spot, they may be persuaded to go elsewhere. Good luck. Please let us know how this situation transpires. The Regal Swan