This flock of swans decided to "winter" in Minnesota rather than flying south. They found a lake that had open water all winter (the lake had an aeration system). One morning after it had snowed overnight, I went out to take photos of the swans. I was surprised to see all the swan tracks in the fresh snow coming the other side of the lake. I'm not sure where they had been, but they were back in the water by the time I got there.