Jeff Vanuga / Bull Bison (Bison bison) warming himself in the steam from the Firehole River, Upper Geyser Basin, Yellowstone National Park, Wyoming, USA, January

Sumio Harada / American Bison (Bison bison) free roaming wild herd along river, Yellowstone National Park, North America

Pete Oxford / Cape Buffalo (Syncerus caffer) veterinary fence to control foot and mouth disease transmission, Moremi Game Reserve, Okavango Delta, Botswana

Yva Momatiuk & John Eastcott / American Bison (Bison bison) herd near river, Yellowstone National Park, Wyoming

Tony Heald / African Buffalo {Syncerus caffer} feeding on aquatic vegetation in Chobe river, Chobe National Park, Botswana

Tony Heald / Buffalo {Syncerus caffer} feeding in Chobe River, Chobe National Park, Botswana

Richard Du Toit / Cape Buffalo (Syncerus caffer) adult male with a Cattle Egret (Bubulcus ibis) feeding on flies gathering near its head, Chobe River, Chobe National Park, Botswana

Ingo Arndt / American Bison (Bison bison) herd at Madison River, Yellowstone National Park, Wyoming

Ingo Arndt / American Bison (Bison bison) mother and calf crossing river, Yellowstone National Park, Wyoming

Jeff Turner / Storm brewing over Peace-Athabasca river Delta, Wood Buffalo NP, Alberta, Canada

Anup Shah / Cape buffalo herd drinking at river {Syncerus caffer caffer} Katavi, Tanzania

Konrad Wothe / American Bison (Bison bison) group along snowy riverbank, Yellowstone National Park, Wyoming

Sumio Harada / American Bison (Bison bison) free roaming wild herd along river, Yellowstone National Park, North America

Bernard Castelein / Meandering river at Alum Creek, Hayden Valley, with buffalo grazing, Yellowstone NP, USA.

Richard Du Toit / Cape buffalo feeding in river {Synceros caffer caffer} Chobe NP, Botswana

Sumio Harada / American Bison (Bison bison) females and calves crossing river, Yellowstone National Park, Wyoming

Michael Quinton / American Bison (Bison bison) herd gathering along misty Yellowstone River, Yellowstone National Park, Wyoming