Winter in Yellowstone National Park is long and brutally cold. It was -20F in Yellowstone and the roads icy and white when I came across a lone bison accompanied by a magpie. The bird was flying around the bison and would not leave him. When the magpie was not flying in the cold air, it would sit on the bison’s head and back to stay warm and seemed to be cleaning the bison’s fur. On one occasion the magpie flew off the bison’s back and landed right in front of the face of the bison and they gazed into each other’s eyes for a moment before the magpie returned to bison’s back. This photo captured that moment.