As stupid and irresponsible some pet owners can be, the cygnets may or may not have been killed by the dog. There are no guarantees that the swans will or will not return. The dog may just have scared the cygnets and the parents took off, abandoning the brood and something else may have gotten to the cygnets while the parents fled such as hawk, owl, egret, heron, turtle, etc.

So, unless someone was present during the cygnet's death, there is no way to tell if the dog was responsible. We have seen swans attacked by predators only to return to the same area time and time again because of the nesting and food resources. If this was a one time occurrence and the parents had habitually nested in this area for years, they may return, knowing that this was a one time event. However, if they were new parents and they were repeatedly wary of predators, they may not come back to the exact location, but stay in the surrounding area. Please let us know if they return. The Regal Swan