Hi,
I just joined in on this conversation and noticed it's a month or so old, how are your swans doing? Are they penned up or loose on a pond? I'm a newbie too and was looking through the posts. Something I didn't see stated here is that the parents may attack the young ones when they get a little older. I read that it takes a "lot" of space to even be able to have a second pair of them to keep them from fighting. I just bought a single male mute swan and I'm looking for a female. Your little ones would be too small I'm afraid but if anyone else sees this they're welcome to PM me.
I am picking mine up next week and have 40 acres here and I still would not have more than one pair, just because. I read that even if they can see or hear the other pair there is trouble. I hope they're all doing great but unless they can be penned apart, you might want to check into this so you don't have the parents attacking the youngsters in the spring when breeding season starts again.
Also, I just finished reading about the royal and the polish types of mutes, then I found it here, too cool