Hi Regal Swan, I wanted to update you on this situation. I was mistaken when I said the cygnet was 13.5 week. He is 14.5 weeks.
I was able to catch him from channel and return him to the pond with the swan family. The time he was missing from the pond was about 24 hours.
The adult female immediately started pursuing the cygnet. The male and female continue to do so and the other cygnets do as well. He has been able to keep out of their reach. And mine, too. I have been trying to recapture him since Tuesday morning but have not been successful. I have called in for assistance.
Will let you know what happens.