Frozen ponds

With this cold snap the ponds have been gradually freezing over and there is only one remaining with a small water hole, where all the ducks gather each day, see the attached photos.
Three additional Swans arrived on the long pond yesterday but had gone today, how did they manage to take off? it took all their skills just to remain standing. One of them had a Blue ring with White writing, I think it was ringed at Ormsgill reservoir.

Lynne, Bob and Bri.