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) breeding colony, males huddling on sea ice during polar night, incubating eggs, ice shelf in background. Atka Bay, Antarctica. July 2017.

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.

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.

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.

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

Chadden Hunter / King penguin (Aptenodytes patagonicus) chick creche enduring harsh weather, South Georgia. Taken on location for BBC Frozen Planet series, 2008

Diane McAllister / Newly hatched Western scrub jay chicks (Aphelocoma californica) huddling together in their nest near one last egg. This nest is in a backyard in Reno. Nevada, USA, June

Yukihiro Fukuda / Two groups of Japanese macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, Japan

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, Japan

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, Japan

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) faces looking up, huddling together for warmth on a cold day, Shodoshima, Japan

Yukihiro Fukuda / Japanese macaques (Macaca fuscata) huddling together for warmth on a cold day, Shodoshima, Japan

Anup Shah / Group of Banded mongoose {Mungos mungo} huddling together, bonding by close contact, Queen Elizabeth NP, Uganda

SIMON KING / Young Meerkats huddling together {Suricata suricatta} Tswalu Kalahari Reserve S Africa

David Tipling / Adult Emperor penguin {Aptenodytes forsteri} with chick at feet huddling for warmth, Weddell Sea, Antarctica

David Tipling / Emperor penguin chicks in creche huddling together for warmth {Aptenodytes forsteri} Weddell sea, Antarctica Dawson-Lambton glacier

Sebastian Kennerknecht / Mountain Lion (Puma concolor) six month old female and male kitten, Torres del Paine National Park, Patagonia, Chile

Cyril Ruoso / Verreaux's Sifaka (Propithecus verreauxi) trio huddling, vulnerable, Berenty Private Reserve, Madagascar

Cyril Ruoso / Ring-tailed Lemur (Lemur catta) group huddles for warmth as they sleep, vulnerable, Berenty Private Reserve, Madagascar

Cyril Ruoso / Barbary Macaque (Macaca sylvanus) male with infant in snow-covered tree, winter, Middle Atlas Mountains, Morocco

Rosl Roessner/ BIA / Guira Cuckoo (Guira guira) group huddled together, native to South America

Thomas Marent / Gelada Baboon (Theropithecus gelada) male and females huddling for warmth, Simien Mountains National Park, Ethiopia

Thomas Marent / Gelada Baboon (Theropithecus gelada) group huddling for warmth, Simien Mountains National Park, Ethiopia