Ben Hall / Mountain hare (Lepus timidus) on snow covered moorland at last light, Derbyshire, UK.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), two adults brooding begging chicks aged five weeks. Atka Bay, Antarctica. September.

Jenny E. Ross / Polar bear (Ursus maritimus) cubs, age 2-3 months, in den, Wapusk National Park, Manitoba, Canada. March.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) pair courting, Atka Bay, Antarctica. Bookplate.

Carol Walker / RF - Percheron horse trotting through snow. Alberta, Canada. Febraury. (This image may be licensed either as rights managed or royalty free.)

Danny Green / Arctic fox (Vulpes lagopus) walking in heavy snow. Hornstrandir Nature Reserve, Iceland. February.

Danny Green / North American river otter (Lontra canadensis) on snow covered bank, reflected in icy water. Yellowstone National Park, USA, January.

Stefan Christmann / Emperor penguins (Aptenodytes fosteri) chicks huddling, Antarctica. Winner of the Portfolio Award, Wildlife Photographer of the Year 2019. Bookplate.

Ross Hoddinott / Robin (Erithacus rubecula) in snow, Broxwater, Cornwall, UK. March.

Marie Read / Northern Cardinals (Cardinalis cardinalis) male and female in the snow, photographed from low angle, Freeville, New York, USA. April 2020.

Marie Read / Red-winged Blackbird (Agelaius phoenicus) male singing from snow-covered red maple (Acer rubrum) in flower, Ithaca, New York, USA. April 2020.

John Cancalosi / Portrait of White-tailed deer (Odocoileus virginianus) doe in snow, New York, USA

John Cancalosi / White-tailed deer (Odocoileus virginianus) doe standing in snow, New York, USA

Danny Green / Willow Tit (Poecile montanus) on a snowy branch. Utsjoki, Finland, February.

Danny Green / Whooper Swans (Cygnus cygnus) in snow. Japan, February.

Danny Green / Mountain hare (Lepus timidus) resting Cairngorms, Scotland, March

Laurent Geslin / Red fox (Vulpes vulpes) at edge of woodland in winter snow, Jura, Switzerland

Markus Varesvuo / Great Grey Owl (Strix nebulosa) Kuhmo Finland, March.

Markus Varesvuo / Bullfinch (Pyrrhula pyrrhula) in flight, Kuusamo, Finland, March.

Markus Varesvuo / Golden eagle (Aquila chrysaetus) landing in snow, Kuusamo, Finland, December..

Jen Guyton / A white-tailed deer (Odocoileus virginianus), habituated after being fed by locals and tourists, sticks its head into the photographer's car in New Brunswick, Canada.

Emanuele Biggi / European red fox (Vulpes vulpes) peeking out of a snow bank. Gran Paradiso National Park, Italy.

Jenny E. Ross / Polar bear cubs (Ursus maritimus) triplets age 2-3 months next to their mother. Wapusk National Park, Manitoba, Canada. February

Jenny E. Ross / Polar bear (Ursus maritimus) cubs, age 2-3 months, in den, Wapusk National Park, Manitoba, Canada. March.

Jenny E. Ross / Polar bear (Ursus maritimus) cubs, age 2-3 months, in den, Wapusk National Park, Manitoba, Canada. March.

Jenny E. Ross / Polar bear (Ursus maritimus) cubs, age 2-3 months, in den, Wapusk National Park, Manitoba, Canada. March.

Jenny E. Ross / Polar bear (Ursus maritimus) and her twin cubs (age 6 months ) at the edge of fjord ice near Nordaustlandet, Svalbard Archipelago, Norway,

Jenny E. Ross / Polar bear (Ursus maritimus) mother and her yearling cub (age 22 months) resting near the edge of the sea ice in Western Hudson Bay, Wapusk National Park, Canada.

Jussi Murtosaari / Snow covered forest in afternoon light. Central Finland. January 2019.

Marie Read / House finch (Carpodacus mexicanus) male in breeding plumage perched amid snow-covered branches in winter, Ithaca, New York, USA, February.

Carol Walker / Percheron horses, two including one dappled grey walking through snow, frosty trees in background. Alberta, Canada. February.

Carol Walker / Haflinger stallion galloping through snow. Quebec, Canada. January.

Carol Walker / Gypsy vanner stallion cantering through snow. Alberta, Canada. February.

Carol Walker / Percheron horses, two walking through snow. Alberta, Canada. February.

Nick Garbutt / RF - Adelie penguin (Pygoscelis adeliae) on iceberg. Graham Passage, Antarctic Peninsula, Antarctica. (This image may be licensed either as rights managed or royalty free.)

Stefan Christmann / Emperor penguins (Aptenodytes fosteri) standing in snow drift, Atka Bay, Antarctica. October. Bookplate.

Stefan Christmann / Emperor penguin (Aptenodytes fosteri) close up, profile with a dusting of snow, Atka Bay, Antarctica. August. Bookplate.

Stefan Christmann / Emperor penguin (Aptenodytes fosteri) chick, aged 9-12 weeks, sheltering against its parent, Atka Bay, Antarctica. October. Bookplate.

Danny Green / Red Deer (Cervus elaphus) Stag in the snow. Scotland, March

Danny Green / Coniferous trees under a thick layer of frozen snow, Northern Finland, February

Danny Green / Great Spotted Woodpecker in snow (Dendrocopos major), Scotland, February.

Nick Garbutt / RF - Red fox (Vulpes vulpes) walking through deep winter snow. Yellowstone National Park, USA. January (This image may be licensed either as rights managed or royalty free.)

Nick Garbutt / RF - North American river otters (Lontra canadensis) (probably female with two juveniles) on the frozen river edge.Yellowstone National Park, USA. January. Digitally stitched image. (This image may be...

Nick Garbutt / RF - North American river otters (Lutra canadiensis) on the frozen river edge. Yellowstone National Park, USA. January (This image may be licensed either as rights managed or royalty free.)

Nick Garbutt / RF - Red fox (Vulpes vulpes) on the edge of coniferous forest. Yellowstone National Park, USA. January (This image may be licensed either as rights managed or royalty free.)

Nick Garbutt / RF - Lodgepole pines (Pinus contorta) covered in heavy early morning hoar frost. Yellowstone National Park, USA. January. Digitally stitched image. (This image may be licensed either as rights managed...

Nick Garbutt / Red fox (Vulpes vulpes) walking through deep winter snow. Hayden Valley, Yellowstone, USA. January

Konrad Wothe / Great tit (Parus major) male in flight, Parus major, winter, Bavaria, Germany, February.