Just one left?

Went over to Hampton Wick Pond today. Haven't been for a couple of months and wondered how the swans and their young were doing. Last time I went there were three cygnets which had been there for months. There were getting very big. Unfortunately today there was only one. Maybe the other two have 'flown the nest', but it seems a bit early for that. Having watched their progress for quite a while I felt quite sad.