Swans

I spotted one of these swans walking across the ice at the tarn today.  I say walking, but it was obvious the ice was somewhat slippy.  

It walked across the width of the tarn before cracking the ice and falling through at which point it's mate came over from the other side and they did the "heads moving together thing".

Swan sliding video here: https://youtu.be/iitgBVqd01U