Doug Allan / Emperor penguin males incubating eggs huddle for warmth at -40 degrees centigrade, winter, Antarctica. Green is excrement on snow. {Aptenodytes forsteri}

Stefan Christmann / Emperor penguin (Aptenodytes fosteri) male peering out, looking over the huddle during polar night, Antarctic winter, Atka Bay, Antarctica. July. Bookplate.

Guy Edwardes / Brown tent-making bats (Uroderma magnirostrum) roosting under a palm leaf, lowland rainforest, Costa Rica. November.

Ernie Janes / Ring-tailed lemur (Lemur catta) two huddled together for warmth. Captive.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony, males huddling whilst incubating eggs. Atka Bay, Antarctica. July. Winner of the Portfolio category of the Wildlife Photographer of the Year Awards 2019.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony huddled together under the Southern Lights, Aurora australis, Atka Bay, Antarctica. September.

Lorraine Bennery / Red-bellied lemur (Eulemur rubriventer) huddling together in tree branches. Anjozorobe Special Reserve, Madagascar. Vulnerable species, endemic.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony with with creche of huddling chicks, Atka Bay, Queen Maud Land, Antarctica. October.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony huddled during polar night, males incubating eggs. Atka Bay, Antarctica. July 2017.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony, males huddling whilst incubating eggs. Atka Bay, Antarctica. July.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony, males huddling whilst incubating eggs. Atka Bay, Antarctica. July.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) males huddling whilst incubating eggs,under full moon during polar night, Atka Bay, Antarctica. July.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony huddling, males incubating eggs, on sea ice under full moon in polar night. Atka Bay, Antarctica. July 2017.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) males in breeding colony incubating eggs, huddling during winter storm. Penguins on outside repositioning themselves to gain protection from weather. Atka Bay, A...

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) males in breeding colony huddling during winter storm. Atka Bay, Antarctica. July.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) breeding colony, mainly males brooding eggs, huddled together on sea ice. Atka Bay, Antarctica. June.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) breeding colony, adults brooding chicks. Atka Bay, Antarctica. September 2017.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), two chicks aged six to eight weeks huddling together. Atka Bay, Antarctica. September.

Klein & Hubert / Emperors penguins (Aptenodytes forsteri) group of chicks on fast ice near colony, Antarctica.

Jack Dykinga / Burrowing owl (Athene cunicularia), two huddled together. Marana, Pima County, Arizona, USA.

Jussi Murtosaari / Blackcap (Sylvia atricapilla) female and two males huddling together for warmth while sleeping, Finland, May.

Fred Olivier / Close-up of a group of Emperor penguin (Aptenodytes forsteri) chicks huddled together in a blizzard, covered in snow, Adelie Land, Antarctica, January.

Fred Olivier / Emperor penguin (Aptenodytes forsteri) chicks huddled together during a blizzard, Adelie Land, Antarctica, January.

Cyril Ruoso / Golden monkey (Rhinopithecus roxellana) females sitting close together with baby inbetween, Qinling Mountains, China.

Markus Varesvuo / Capercaillie (Tetrao urogallus) chicks huddled together, Kuhmo, Finland, June.

Tui De Roy / Little blue / fairy penguin (Eudyptula minor) walking on pathway to nesting burrows, Neck Game Reserve, Bruny Island, Tasmania, Australia, December.

Sergey Gorshkov / Musk ox (Ovibos moschatus) herd, Wrangel Island, Far Eastern Russia, March.

Sergey Gorshkov / Musk ox (Ovibos moschatus) portrait, Wrangel Island, Far Eastern Russia, March.

Konrad Wothe / Chimpanzee (Pan troglodytes) sitting in the rain, Mahale Mountains National Park, Tanzania.

Denis-Huot / Wildebeest (Connochaetes taurinus) herd in the rain, Masai-Mara Game Reserve, Kenya

David Tipling / Emperor Penguins, (Aptenodytes forsteri), young huddling together to form a creche to keep warm, during storm, Dawson Lambton Glacier, Weddell Sea, Antarctica

David Tipling / King Penguins (Aptenodytes patagonicus) group huddled together in storm, Right Whale Bay, South Georgia, November

David Tipling / King Penguins (Aptenodytes patagonicus) group huddled together in blizzard, Right Whale Bay, South Georgia, November

Markus Varesvuo / Common Raven (Corvus corax) huddled down amidst snow storm, Utajarvi Finland, February

Andy Rouse / Walrus (Odobenbus rosmarus) colony discharging gas on beach. Svalbard, Norway, August 2011.

Sven Zacek / Small herd of Roe Deer (Capreolus capreolus) looking back at the photographer against forested background. Virumaa, Estonia, Europe, February.

Mark Carwardine / Common shelduck (Tadorna tadorna) ducklings huddled together, Slimbridge, Gloucestershire, UK, June

Anup Shah / Impala herd (Aepyceros melampus) huddled together in the rain, Masai Mara National Reserve, Kenya. April

Charlie Summers / King Penguin (Aptenodytes patagonicus) adult surrounded by huddled chicks, riding out a snowstorm at Gold Harbor, South Georgia.

David Tipling / King Penguin {Aptenodytes patagonicus} colony huddled together during storm, adults and juveniles, Right Whale Bay, South Georgia, November

David Tipling / King Penguin {Aptenodytes patagonicus} colony huddled together during storm, Right Whale Bay, South Georgia, November

David Tipling / King Penguin {Aptenodytes patagonicus} colony huddled together during storm, Right Whale Bay, South Georgia, November

David Tipling / King Penguin {Aptenodytes patagonicus} colony huddled together during storm, Right Whale Bay, South Georgia, November

David Tipling / King Penguin {Aptenodytes patagonicus} colony huddled together during storm, Right Whale Bay, South Georgia, November

David Tipling / King Penguin {Aptenodytes patagonicus} colony huddled together during blizzard, Right Whale Bay, South Georgia, November

David Tipling / King Penguin {Aptenodytes patagonicus} colony huddled together during storm, Right Whale Bay, South Georgia, November

Anup Shah / Gelada baboon (Theropithecus gelada) group huddled together, resting and grooming in the early morning, Simien Mountains National Park, Ethiopia, November

Fiona Rogers / Gelada baboon (Theropithecus gelada) mature male and juvenile huddled together from the rain, Simien Mountains National Park, Ethiopia, November