We adopted a swan (Henry) a little less than a year ago. He is now approximately 3 years old, he has full run of our pond which takes up approximately 1 acre (on about 3.5 acres of ground) and he is the only swan. For the first couple of months he was pretty friendly (at least with me). I could be within a couple of feet from him and all was good. Suddenly he became very aggressive towards everyone including me. He charges everyone in his vicinity on a regular basis. He even leaves our yard to charge at the neighbors. I am sure he is frustrated because he can't fly (pinioned) and possibly because he doesn't have a mate. If I get him a mate would it help or make things worse? Do I find a wildlife sanctuary for him? So far the neighbors have been pretty good about him but I am waiting for the day the police arrive due a complaint about him. I really want Henry to be a happy bird, I just don't know what he needs from us.