The pond could support a number of swans, but realistically, black swans are the most aggressive of the swan species, so problems will arise if you keep more than 2 pair of swans on this particular pond. As long as the parents are good parents, and keep each of the families away from each other (separate sides of the pond), you could keep the cygnets until they are approximately 5-6 months of age, which is when the parents will tell the cygnets it is time to leave before the next breeding season.

Because Black swans mate and produce 2 clutches a year, 5-6 months of age, is probably not going to work. Realistically, the cygnets will need to be placed in another pond at 4 months of age or when the parents begin letting them go around the pond by themselves. Again, this is going to cause a major war if the two families come together as the opposite parents may try to kill the cygnets from the other family. Also, if the more dominant pair are successful, they will keep the other family completely out of the pond and from eating, bathing and cooling themselves in the water. If this happens in the summer heat, all swans could perish.

If the dominant pair of swans run the other swans completely out of the pond, then you will have another problem, wandering swans. The swans may pick-up and take their cygnets to find another pond and now you risk the possibility of predators, both animals and humans causing them great harm.

Therefore, our suggestion would be that only 2 pairs of swans (max) be kept on the lake and that the cygnets be removed by 4 months of age. Also, many states require permits for the swans and it is a neccessity to have the cygnets pinioned at 1-3 weeks of age so that they cannot fly. The major issue is where the young swans will be placed so that the care provided to keep them alive is not lost within the next few months because there is not a suitable home to place the cygnets. The Regal Swan