I had three swans that got along fine for about a year. Then suddenly the largest one ran one of the others away to a nearby lake. I assume the remaining pair are male and female. The lone swan seems to have traits similar to the paired off female(size of neck and gentle nature) Both the paired off female and the loner will eat out of my hand but the larger necked aggressor of the pair acts as if he would starve before eating from my hand. This leads me to believe that the one chased away is a female but logically I would think the aggressor would only chase away another male. We want to get a mate for the lone swan but need advice as to whether you think this lone swan to be male or female based on this information. Also, with a mate is it ever likely that they could all live together in harmony on a 1 acre pond?