Yes, swans are a little different as they can really imprint on people and territories. You might try the island, but we're not sure how far out into the pond you can secure the island. You will need to be directly in the middle so that predators cannot swim to the swans. As far as training them to use the island at night, there are no guarantees that they will stay there all the time. If they get bored and start to roam around the edges of the pond at night instead of staying on the island, they will be killed by predators. We're sure that you do not wish to stay up all night watching them, and even if you did for the first couple of nights, they may get used to you being around and once you leave, they may try to follow you in the middle of the night, which would still end up with a predator issue. Let us know how this progresses. The Regal Swan