But English swans retain their willingness to live at close quarters with humans. We should repay the compliment. Like most of us, swans just need space. Keep dogs on leads near them.

The counters on the River Thames recorded 94 cygnets, as young swans are called, compared to 155 last year. That’s a roughly 40 percent drop, and a worry for conservators and animal lovers alike.

Swan Lake from English National Ballet is produced for English National Ballet by Ad Lib Productions (1x130) for BBC Two and BBC iPlayer. It was commissioned by BBC Arts.