It was noted that, by the time of the 2006 Academy Awards, this Best Documentary winner had out-grossed all 5 Best Picture nominees ($77 million vs. $75 million for Brokeback Mountain (2005)).
The Emperor Penguin (Aptenodytes forsteri) is the tallest and heaviest of all living penguins and the only one to breed during the winter in Antarctica.
When released, became the second highest grossing theatrical documentary (after Fahrenheit 9/11 (2004)).
Morgan Freeman almost passed on narrating the film, having told his agent that he was tired of being typecast as a narrator and to stop sending him those offers. He was persuaded to take a look at this film and changed his mind.