Yes, you have a problem, especially during mating/breeding season which is going to be three times in your case. Black swans mate and produce cygnets twice a year and the mute swans mate and produce cygnets once a year. This problem is going to get extremely hectic once the cygnets are hatched and parents do not want anyone or anything near their young.

There are a couple of ideas that might work. One would be to increase the feeding stations around the dam. Place two or three more feeders throughout the habitat so that, hopefully, the various pairs will claim one as their own and will stay in that section of the pond.

Two, build a veterinary pen (1/in water, 1/2 on land with feeder inside). Ensure that the pen is covered on the bottom and top so that no predator can access the family by digging under or climbing over the pen. You will need to use this pen as a breeding pen, meaning that any nesting that takes place by any pair, must occur in this pen. This will allow the parents to worry more about taking care of their cygnets rather than chasing and terrorizing the other swans. Unfortunately, this means that the cygnets must be about 4 months of age in order to have the family released. This will allow the young birds to get big enough that they will either learn to stay away from the other swans or be astute and large enough to escape from any attacks from other adult swans. THIS STILL MAY NOT SAVE cygnets from being caught in the middle of parental fights or attacks from the older swans which may result in serious injury or death. Once the cygnets are approximately 8-10 months of age, you will need to find them another home or there are going to be increased fights and problems on the pond.

Three, fence off a section of the pond for black swans and one section for mute swans and add feeders. Fencing should be such that the birds and their young cannot get their heads or necks stuck in the fencing to drown or cause injury. If you use a chain link fence, you can add slats through the fencing so that the birds cannot try to get through the fencing nor see to the other side. IF A SWAN CANNOT SEE THROUGH SOMETHING, IT WILL NOT TRY TO GET TO THE OTHER SIDE! Fencing should also be at least 4 feet high so that the birds cannot attempt to climb over the fence and get hurt.

Usually, black swans are much more aggressive than the mute swans, but all of this changes during mating/breeding season. Again, you have a situation in which there is going to be a pair of swans and their cygnets in a territorial fight throughout the year due to the number of breeding seasons. If this problem does not get rectified with new feeders or veterinary pens, we're afraid that one of the pair of swans will need to be found a good home. Good luck. Please let us know how this situation progresses. The Regal Swan