This is not something that we recommend unless you bring your swans inside at night. If the strobe light affects geese or other birds, it is going to have the same detrimental effect on your swans. The swans may become stressed, try to leave the area (not good because they probably can't fly and will walk into an area with domestic or wild predators and be attacked or killed), or due to the stress, stop eating, get sick and die. Not good. Usually, especially during nesting season, the swans will start to act up (become territorial) and chase the geese. Is this not something that they do during nesting season? The Regal Swan