Two emperor penguins

A cold day. Emperor penguins have a range of stances according to how active they are and what the temperature is. Sometimes they can stretch upwards and become tall and thin, at other times like this they sort of slouch down and become short and fat, (this gives scientists a problem when measuring them as they're not so amenable as people when being measured!). This pair probably have an egg or chick each under their brood flaps and so are not a mated couple as first appears, but are waiting for their respective mates to return from a fishing trip.

Squatting down like this will decrease the penguin's surface area to volume ratio and so make them more efficient at retaining heat.

This picture by Jérôme Maison. © 2005 Bonne Pioche Productions / Alliance De Production Cinématographique.
From the Warner Brothers film The March of the Penguins used here by permission of Warner Brothers.