Did you get the swans from a reputable breeder? Are you in a state that requires veterinary checks on the swans prior to sale? If so, the person who sold or delivered the swans is responsible for replacing the second swan.

If there is any predator in the area, no matter what you do, the swans will probably not survive unless you train them to be released onto the pond one hour after daybreak and bring them indoors or into a pen (enclosed top to bottom with feeder inside, pen 1/in water and 1/2 on land) one hour before dusk. The pen or enclosure must be protected from predators digging under the pen or climbing into the pen.

Most predators start preying between dusk and dawn. Even then, a rogue nocturnal predator may hunt during the daytime if resources are not available due to inclement weather, flooding, drought or other adverse conditions.

Using the same qualifications for the pen described above, you must keep the swans in the pen for approximately 2 weeks so that they understand how to get food from their feeder, introduce themselves to the new habitat and you. Good luck. The Regal Swan