The ice need not be very thick for animals to make tracks across it. That has surprised me. I realized it needn’t be as thick for them as it must be for me, but still it seems to be one good hard freeze and a layer will support most of the denizens of the riverbank. Perhaps not the beaver.
I laughed when I saw this pair of prints where even the surefooted animal hadn’t been able to keep their balance. It may have been that it was moving in a hurry, since animals seem to be quite careful about where their feet are going.