There are no guarantees that he will re-mate. Usually, depending upon species and the individual swan, most males will not re-mate once they have lost their female mates. Females, on the other hand will usually re-mate.

Are you absolutely sure it is a male? Has there been DNA Sequencing or probing done by a licensed laboratory or veterinarian? Should you place the same gender on the pond, it may mean death or serious injury to one or both swans.

Additionally, it is now required by some states to have a permit to possess a swan and if you have a mating pair, you may require a breeders' license because the pair can produce cygnets and you will be responsible for any pinioning, micro-chipping, veterinary care and finding the cygnets a new home once they are chased from the pond during the next breeding cycle. Depending on swan species, a pair of swans can produce anywhere from 1-8 cygnets a year, with Black swan pairs producing 2 clutches a year. This is a lot of swans for someone to maintain.

We would suggest that you not try to find it a new mate because not only is there no guarantee that the swan will accept another bird, but if the age of the bird is quite old, he/she could succumb to old age and then you would still have a new bird with no mate.

You describe his behavior as aggressive, but it may be defensive, which is entirely two different things. The aggressive/defensive behavior may be due to the fact that he saw his mate being killed or tried to fend off the attack and he is now very wary of humans and predators. It also might be the time of the season if his hormones have not settled from the last mating/nesting season, he may be showing some aggression/defensive/territorial behavior. In any case, this may be a means for him to protect himself from injury or death like his mate. The Regal Swan