If they are all females, then there should not be a problem. If there is a male and two females, there will be a female left out during mating season, and they may chase her, but usually, the male is the one less tolerant during mating season. In this case, he will not harm a female, but if you have two males, then there could be fights and other problems. You need to get them sexed to determine exactly what you have. A licensed veterinarian can take a feather with some genetic material and have it processed. The DNA sequencing will provide you with the necessary information on what to do with this situation.

Also, can you capture the swan that can fly? If so, you need to clip her/his wings so that he/she cannot fly. In most states, if a captive Mute Swan can fly, state wildlife officials will shoot it or kill it in some manner. The reason for this is that the federal and state wildlife agencies throughout the U.S. are trying to eradicate all Mute Swans from wetland habitats so they can introduce the larger Trumpeter Swans for Trophy Waterfowl hunting purposes. So, in order to keep you swans safe, they need to stay on your pond. Should you have two males, you need to find the extra swan a good safe home. The Regal Swan