Photo of the Week: Bison on the March

Panagiotis Laskarakis was visiting Yellowstone National Park’s Lamar Valley when he spotted a herd of bison marching in his direction. “I had the feeling of being attacked by a bison army,” the resident of Greece wrote. Laskarakis quickly photographed the moving herd despite the -22 degree temperature. He used a Canon EOS 7D camera and a 100-400mm lens.