First, you may need a permit to bring swans into your state. There are no guarantees that swans will or will not chase the geese. It totally depends on the species and the individual swans. Some swans have no problem with the geese while others become so territorial that the geese will eventually leave.

Black swans may not be a good idea because of the cold winters and the need to bring them in under extreme cold temperatures. This time lapse may cause the geese population to thrive even more. Also, black swans are about 20 pounds lighter than a mute swan (which is adaptable to cold temperatures as white swans are nothern hemisphere swans and swans with black coloring are southern hemisphere swans).

Although black swans are much more aggressive, they may be too little to go up against an aggressive goose. You really need to discuss this issue with Bob at Knox Swans. Bob provides swans and dogs to alleviate geese problems. The Regal Swan