The Mute Swan you describe sounds as if it may be someone's captive swan. It is banded which means that it is either identified as belonging to someone or the bird was banded by a wildlife association to ascertain where the bird might be traveling.

You might ask someone in your homeowner's association to see if they may have placed the swan on the pond to provide it a safe home and adorn the pond.

If you can get close enough to read the number, you might check with the local wildlife/bird associations to see if there is identification information on the bird. We hope this information is of benefit. The Regal Swan