Penguin

Everyone knows penguins can't fly. Far fewer people know that emperor penguins dive to 565 meters and hold their breath for 22 minutes, that male emperors incubate eggs through Antarctic winters at -60°C in rotating huddles that generate internal temperatures of 37°C, or that penguins recognize each other's calls individually in a colony of tens of thousands.

Facts you didn't know

• 1

  Emperor penguins dive to 565 meters and hold their breath for up to 22 minutes — deeper than most submarines operate in routine service, and longer than any competitive breath-hold swimmer has lasted.

• 2

  Penguins 'fly' underwater. Their stroke mechanics, wing anatomy, and hydrodynamic efficiency are directly analogous to bird flight — the same muscular adaptations used by flying birds, applied to a denser medium.

• 3

  Male emperor penguins incubate eggs through the Antarctic winter at -60°C, standing in rotating huddles that generate 37°C at the center. Each male takes turns on the cold outer edge, sharing the worst exposure evenly.

• 4

  Penguins recognize each other's voices individually in a colony of tens of thousands. Parents and chicks locate each other by call alone after months apart, and mated pairs identify each other with specific vocal sequences.

• 5

  Penguin guano has formed deep geological strata visible in Antarctic ice cores, providing a population history going back thousands of years before any human records — the birds have been inadvertently documenting themselves.