Your babies are no longer babies but adults getting ready to mate and produce their first cygnets. If this is the second or third time to produce cygnets, then the birds have now learned how to become parents and protect their youngsters. He thinks you and the family are now a threat to his cygnets.

Black Swans are usually the most aggressive of all swan species, but we have seen this species be just as docile as any other species in the right setting. Black Swans are also the only species of swans that produce two broods a year. Once in the winter and once in the summer. So, your swans are getting ready to go into the winter breeding season and this might be the reason for his behavior. You will just need to give him his space or grab him when he threatens you and tell him NO. Let him know that his behavior is unacceptable around you or your family. However, note that this conditioning could cause him to lose all defensiveness around other people or predators and may not protect himself.

The ideal situation is to pen his food, his wife, his area and his pool to a 12-24 foot pen (completely enclosed top to bottom to prevent any predators from digging under the pen or climbing into the pen). Let him go through his mating and nesting in the pen. Once his hormones settle, he'll go back to being his loving self.

Also, ensure that the pool is sunken into the ground, zero level entrance or the parents and especially the young cygnets can damage their feet and legs to the point that they may not recover from the injuries. You will need to clean (pump) the pool out daily to provide clean water for the young cygnets and add their food to the pool so that they learn from their parents how to retrieve food in the water. Good luck. The Regal Swan