Konrad Wothe / Coyote (Canis latrans) in winter, Alleens Park, Colorado

Thomas Mangelsen / Polar Bear (Ursus maritimus) rolling in snow, Hudson Bay, Churchill, Manitoba, Canada

Sumio Harada / Mountain Goat (Oreamnos americanus) leaping in snow, Rocky Mountains, Glacier National Park, Montana

Sumio Harada / Bighorn Sheep (Ovis canadensis) males butting heads while a third looks on, Rocky Mountains, North America

Konrad Wothe / Siberian Tiger (Panthera tigris altaica) in snow, Siberian Tiger Park, Harbin, China

Konrad Wothe / Siberian Tiger (Panthera tigris altaica) walking in snow, Siberian Tiger Park, Harbin, China

Yva Momatiuk & John Eastcott / Bald Eagle (Haliaeetus leucocephalus) adult flying against clear blue sky, spring, south central Alaska

Konrad Wothe / Whooper Swan (Cygnus cygnus) pair arguing at wintering site, Kussharo-ko, Hokkaido, Japan

Yva Momatiuk & John Eastcott / Barn Owl (Tyto alba) portrait against blue sky in desert, spring, Arizona-Sonora Desert Museum, Arizona

Thomas Mangelsen / Polar Bear (Ursus maritimus) sitting up, Churchill, Manitoba, Canada

Matthias Breiter / Polar Bear (Ursus maritimus) mother with cub in snow, Churchill, Manitoba, Canada

Matthias Breiter / Polar Bear (Ursus maritimus) mother with cub, Churchill, Manitoba, Canada

Tim Fitzharris / Timber Wolf (Canis lupus) portrait of pair sitting in snow, North America

Colin Monteath / Climber enjoying view of Mt CookÆs Caroline Face from Ball Pass, Mt Cook National Park, New Zealand

Thomas Mangelsen / Short-tailed Weasel (Mustela erminea) camouflaged against snowbank, Grand Teton National Park, Wyoming

Thomas Mangelsen / Polar Bear (Ursus maritimus) mother and cub, Churchill, Manitoba, Canada

Colin Monteath / Climber hauls load above 4,200 meter camp on the west buttress route of Mt Denali or Mt McKinley which reaches 6,194 meters elevation, Denali National Park and Preserve, Alaska

Matthias Breiter / Polar Bear (Ursus maritimus) adult male charging opponent, Churchill, Manitoba, Canada

Konrad Wothe / Giant Panda (Ailuropoda melanoleuca) eating bamboo, Wolong Valley, China

Konrad Wothe / Siberian Tiger (Panthera tigris altaica) resting in snow, Siberian Tiger Park, Harbin, China

Konrad Wothe / Emperor Penguin (Aptenodytes forsteri) parents with chicks, Antarctica

Konrad Wothe / Giant Panda (Ailuropoda melanoleuca), Wolong Valley, Himalaya, China

Gerry Ellis / Snowy Owl (Nyctea scandiaca) camouflaged against snow, North America

Matthias Breiter / Polar Bear (Ursus maritimus) male resting on ice, Churchill, Manitoba, Canada

Matthias Breiter / Polar Bear (Ursus maritimus) adult portrait, Churchill, Manitoba, Canada

Norbert Wu / Orca (Orcinus orca) pod surfacing in icebreaker channel, must find open pockets of water to breathe, McMurdo Sound, Antarctica

Konrad Wothe / Chinstrap Penguin (Pygoscelis antarctica), Antarctica

Mitsuaki Iwago / Blue Wildebeest (Connochaetes taurinus) herd descending cliff during migration, Serengeti

Mitsuaki Iwago / Polar Bear (Ursus maritimus) close up portrait, Churchill, Canada

Jim Brandenburg / Timber Wolf (Canis lupus) camouflaged amid snowy trees, Minnesota

Jim Brandenburg / Timber Wolf (Canis lupus) pack, Minnesota

Michio Hoshino / Bald Eagle (Haliaeetus leucocephalus) perching on a snag, Alaska

Tim Fitzharris / Red Fox (Vulpes vulpes) pair in snow fall showing the black and red markings of their cross phase, Montana

Jim Brandenburg / Timber Wolf (Canis lupus) trio running through deep snow, Minnesota

Jim Brandenburg / Timber Wolf (Canis lupus) howling in light snowfall, Minnesota

Jim Brandenburg / Timber Wolf (Canis lupus) pair running through deep snow, Minnesota

Jim Brandenburg / Timber Wolf (Canis lupus) portrait, Minnesota

Michael Quinton / Long-tailed Weasel (Mustela frenata) camouflaged in white winter coat, Idaho

Michael Quinton / Northern Hawk Owl (Surnia ulula) perching on branch during snowfall in spring, Alaska

Michio Hoshino / Arctic Ground Squirrel (Spermophilus parryii) peeking out of its hole, Alaska

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

Michio Hoshino / Polar Bear (Ursus maritimus) pair loafing, Churchill, Manitoba, Canada

Mitsuaki Iwago / Saint Bernard (Canis familiaris) puppies nuzzling in snow, Japan

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) pair sky pointing to keep cool in hot sun, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Blue-footed Booby (Sula nebouxii) pair overlooking nesting colony, Punta Vicente, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Gentoo Penguin (Pygoscelis papua) commuting flock climbing snowy slope, Couverville Island, Antarctica

Tui De Roy / Adelie Penguin (Pygoscelis adeliae) group crowding on melting summer ice floe, Possession Island, Ross Sea, Antarctica

Tui De Roy / Bearded Seal (Erignathus barbatus) resting on ice floe near Wagon Way Glacier, Magdalenefjorden, Spitsbergen, Svalbard, Norwegian Arctic

Michio Hoshino / Polar Bear (Ursus maritimus) cubs on snow field, Churchill, Manitoba, Canada

Mitsuaki Iwago / Adelie Penguin (Pygoscelis adeliae) with wings outstretched, Antarctica

Jim Brandenburg / Arctic Wolf (Canis lupus) in blizzard, Ellesmere Island, Nunavut, Canada

Mitsuaki Iwago / Harp Seal (Phoca groenlandicus) pup portrait, Gulf of St Lawrence, Canada

Jim Brandenburg / Siberian Tiger (Panthera tigris altaica) portrait, Asia

Jim Brandenburg / Timber Wolf (Canis lupus) emerging from snowy forest, Minnesota

Tui De Roy / Adelie Penguin (Pygoscelis adeliae) group crowding on melting summer ice floe, Possession Island, Ross Sea, Antarctica

Tui De Roy / Emperor Penguin (Aptenodytes forsteri) group, near Ekstrom Ice Shelf, Weddell Sea, Antarctica

Michio Hoshino / Harp Seal (Phoca groenlandicus) portrait, Gulf of St Lawrence, Canada

Michio Hoshino / Harp Seal (Phoca groenlandicus) pup, Gulf of St Lawrence, Canada

Michio Hoshino / Harp Seal (Phoca groenlandicus) mother and pup, Gulf of St Lawrence, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) sunning, Churchill, Manitoba, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) portrait, Churchill, Manitoba, Canada

Jim Brandenburg / Timber Wolf (Canis lupus) walking, Northwoods, Minnesota

Jim Brandenburg / Timber Wolf (Canis lupus) standing in snow, Minnesota

Michio Hoshino / Polar Bear (Ursus maritimus) cub nuzzling mother, Churchill, Manitoba, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) mother and two cubs, Churchill, Manitoba, Canada

Michio Hoshino / Harp Seal (Phoca groenlandicus) pup portrait, Gulf of St Lawrence, Canada

Michio Hoshino / Harp Seal (Phoca groenlandicus) pup portrait, Gulf of St Lawrence, Canada

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

Jim Brandenburg / Arctic Wolf (Canis lupus) walking into wind, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Muskox (Ovibos moschatus) herd in defensive formation, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Timber Wolf (Canis lupus) pack at White-tailed Deer (Odocoileus virginianus) kill, Minnesota

Jim Brandenburg / Timber Wolf (Canis lupus) trio tugging on White-tailed Deer (Odocoileus virginianus) skin, Minnesota

Michio Hoshino / Polar Bear (Ursus maritimus) mother and cubs in snow storm, Churchill, Manitoba, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) mother and two cubs, Churchill, Manitoba, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) standing, Churchill, Manitoba, Canada

Mitsuaki Iwago / Japanese Macaque (Macaca fuscata) young holding a snow ball, Japan

Michio Hoshino / Polar Bear (Ursus maritimus) mother and two cubs crossing icefield, Churchill, Manitoba, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) laying on stomach, Churchill, Manitoba, Canada

Michio Hoshino / Harp Seal (Phoca groenlandicus) pup, Gulf of St Lawrence, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) portrait, Churchill, Manitoba, Canada

Michio Hoshino / Polar Bear (Ursus maritimus) pair, Churchill, Manitoba, Canada

Tim Fitzharris / Timber Wolf (Canis lupus) trio playing in snow, Montana

Mark Raycroft / Siberian Husky (Canis familiaris) in winter, North America

Jeff Foott / Tourists and Delicate Arch, Arches National Park, Utah

Jeff Foott / Tourists at Delicate Arch, Arches National Park, Utah

Alan Murphy/ BIA / Steller's Jay (Cyanocitta stelleri) in snowfall, Alaska

Ralf Kistowski/ BIA / Coyote (Canis latrans) in winter, Yellowstone National Park, Wyoming

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) standing in front of huddling breeding colony. Atka Bay, Antarctica. August 2017.

Sven Zacek / Great tit (Parus major) flying in falling snow. Vorumaa, Southern Estonia. February.

Sven Zacek / Black grouse (Tetrao tetrix) male displaying at frozen lek. Vorumaa, Southern Estonia. April.

Sven Zacek / Black grouse (Tetrao tetrix) male displaying at lek, in frost. Vorumaa, Southern Estonia. April.

Sven Zacek / Roe deer (Capreolus capreolus) fawn in snow. Tartumaa, Southern Estonia. November.

Sven Zacek / Black grouse (Tetrao tetrix) male displaying at lek in frost. Vorumaa, Southern Estonia. April.

Paul Hobson / Brown-hooded parrot (Pyrilia haematotis), two perched on branch in rain. Costa Rica.

Donald M. Jones / White-tailed Ptarmigan (Lagopus leucura) in winter plumage, browsing on Willow (Salix sp) buds, Alberta, Canada

Donald M. Jones / Red Squirrel (Tamiasciurus hudsonicus) in winter, Montana