If the swan is healthy, there is nothing wrong with him/her being left alone. In fact, most swans if they have lost a mate or never had a mate may not accept another swan in the habitat. The only way to introduce such as swan is to sex the lonely swan to find an opposite gendered swan. Again, after all of this trouble, there are no guarantees that it will accept a potential mate.

In a retirement facility, it is quite difficult to find someone who can adequately prepare for the introduction of another swan, as you have to build a pen, etc. You cannot just dump another swan into the habitat and expect the swan to accept the new swan. Without an introduction pen, both could fight with one or both swan seriously injured from fights.

Finally, to get an opposite gendered swan means the possibility of baby swans (cygnets) being produced. This means more laborious care and time that the retirement facility may or may not have.

In most states, you would need a breeder's license if the swans are not grandfathered and even then, you may still need such a permit. This will also involve extra money for additional veterinary care, pinioning, vaccinations, etc. and permits to find the swans a new home when they are eventually chased from the habitat.

In some states, wildlife officials may even prevent the possession of the swans and even kill them. In light of all of the above, it would be better to let him/her live his life in a habitat that is familiar and has been the only home known by the swan. No sense in upsetting a stable setting. Many times people try to equate people feelings to animals/birds such as loneliness, grief, etc. This usually is the exact opposite of what actually occurs in nature. Yes, there may be some grief at the loss of a mate, but the grief does not last as in humans or it could be detrimental to the individual member of the flock as well as the entire flock due to failure to eat, produce etc. This can also go with the thought of possible loneliness. If the habitat has geese, ducks and other birds and wildlife, it is not likely that loneliness even enters the equation as survival is most important. The Regal Swan