American Buffalo (Bison bison), portrait of a bull in heat, Yellowstone National Park, Wyoming, USA

america american animal animals area areas artiodactyla bison bison bisons bovid bovidae bovids bovinae bovine bovines buffalo buffalo buffaloes buffalos bull bulls conservation day daylight daytime during even even toed exterior exteriors fauna head heads heat horn horns in kingdom male mammal mammalia mammalian mammalians mammals mating national national natural nature nobody north of one outdoor park park parks photo photos portrait portraits preserve preserves reserve reserves ruminant ruminants rut rutting sanctuaries sanctuary season separate separately shot shots single singly snout snouts the toed toed ungulate ungulates usa vertebrate vertebrates wild wildlife world wyoming yellowstone