Emperor penguin huddle
 - Aptenodytes forsteri

Emperor penguins in a huddle during a snow-storm. Normally penguins are very territorial and will not approach each other easily, but this behaviour is one of the ways that emperor penguins manage to survive successfully in the depths of the Antarctic winter. Scientific measurements and calculations have shown that by huddling together, emperor penguins use about half the energy that they would otherwise and would starve to death over the winter rather than come through and raise chicks as well.

There is a constant changing of position from the outside to the inside and during a snow storm lasting days, the whole huddle will slowly move a couple of hundred meters or more.