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

Doug Allan / Emperor penguin {Aptenodytes forsteri} males huddle for warmth in minus 40 degrees centigrade while incubating eggs in winter, Antarctica Winter extreme cold survival birds seabirds nesting-behaviour

Wim van den Heever / King penguins (Aptenodytes patagonicus) at sunrise. Two males and a female, with the males fighting for the attention of the female. Falklands Islands. 2018 Wildlife Photographer of the Year LUMIX Peo...

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) chick begging for food, on parent's feet. Atka Bay, Antarctica. August.

Stefan Christmann / Cameraman Lindsay McCrae filming Emperor penguin (Aptenodytes forsteri) colony for BBC Dynasties Penguin programme. Chicks are on sea ice whilst parents fish at sea. Atka Bay, Antarctica. December 201...

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) group clambering up slope during journey to bring back food for young. Atka Bay, Antarctica. September.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) group in procession across ice shelf to provide food for young. Atka Bay, Antarctica. September 2017.

Frederique Olivier / Emperor penguin (Aptenodytes forsteri) chick begging for food from parent, Adelie Land, Antarctica, January.

Heike Odermatt / King Penguin (Aptenodytes patagonicus) chick begging for food, Saunders Island, Falkland Islands

Stefan Christmann / Emperor Penguin (Aptenodytes forsteri) huddling with chicks for warmth, Queen Maud Land, Antarctica

Stefan Christmann / Emperor Penguin (Aptenodytes forsteri) colony huddling for warmth, Queen Maud Land, Antarctica

Stefan Christmann / Emperor Penguin (Aptenodytes forsteri) colony huddling for warmth, Queen Maud Land, Antarctica