Busking not as in a street performance, but a threat display or the same posture used for “wind-assisted transportation” per Wikipedia.

The wind assist was not something I’ve seen described elsewhere, but there was a stiff breeze this day. Two Mute Swans were traveling the length of this 600 foot (185M) long pond in no time, so it would not surprise me.

A water performance and no tips expected, the Mute Swans at Middleton Place were very entertaining.
Like ballet! these pics are precious.
ps. I shared on twitter.
Yes, very dance-like in their moves. Thanks, Liz!
How pretty!