In the morning after a snowy night, Bison in Yellowstone National Park are encrusted with snow. If they sleep near a thermal feature or hot springs the snow turns to ice that clings to their pelt in clumps. When they arise in the morning, they shake off the snow that has accumulated on them during the night. The Bison cow on the left has just begun to shake off the snow. The calf to her right is still encrusted.