Ingo Arndt / Caribou (Rangifer tarandus) herd crossing a Kongakut River during summer migration, Arctic National Wildlife Refuge, Alaska

Katherine Feng / Giant Panda (Ailuropoda melanoleuca) cubs arranged to photograph all 16 cubs together, Wolong Nature Reserve, China, sequence 3 of 3

Katherine Feng / Giant Panda (Ailuropoda melanoleuca) sixteen cubs escape photo attempt, Wolong Nature Reserve, China, sequence 2 of 3

Richard Du Toit / Cape Buffalo (Syncerus caffer) herd, Okavango Delta, Botswana

Mitsuaki Iwago / Cape Buffalo (Syncerus caffer) herd chasing African Lion (Panthera leo) pair, Serengeti National Park, Tanzania

Gerry Ellis / African Elephant (Loxodonta africana) herd of adults and calves running, Linyanti Swamp, Botswana

Yva Momatiuk & John Eastcott / Mustang (Equus caballus) family band running together in desert, Fifteen Mile Herd Management Area, central Wyoming

Michio Hoshino / Caribou (Rangifer tarandus) herd stampeding, Arctic National Wildlife Refuge, Alaska

Jim Brandenburg / American Bison (Bison bison) herd stampeding, South Dakota

Jim Brandenburg / American Bison (Bison bison) herd stampeding, South Dakota

Michio Hoshino / Caribou (Rangifer tarandus) stampeding herd crossing river, Arctic National Wildlife Refuge, Alaska

Jim Brandenburg / American Bison (Bison bison) herd stampeding, South Dakota