So, turns out one of the tricks to emperor penguins being able to stay under water so long is that they can metabolize anaerobically-that is, without oxygen. Not so surprising for bacteria (at least we’ve known about that for a while), but for a bird, pretty awesome adaptation. Read about it here, and find out about the technical mechanisms and triggers for the switch here.
Don’t Hold Your Breath! (You’re not a penguin)