Research: Penguins warm up with wave
LOS ANGELES — If you’re in stop-and-go traffic, you’re probably pretty unhappy about it.
If you’re a male penguin balancing an egg on your feet in the freezing Antarctic, that traffic jam is probably keeping you alive.
Scientists studying huddles of emperor penguins in Antarctica have discovered that waves of movement travel though huddled masses of flightless birds rather as they do through cars stuck on the freeway during rush hour — but in ways that maximize the huddle’s density and keep the birds warm as they incubate their eggs.
Emperor penguins are the only vertebrate species that breeds during the Antarctic winter, and they face freezing winds that can blow up to 124 mph in an icy landscape that can be as cold as 58 degrees below zero.
So they huddle together against the harsh elements, and together, their bodies can raise the temperature within two hours to as high as 98.6 degrees.
At first glance, the penguins may not appear to move much. The males probably can’t rush anywhere, in any case: The fathers-to-be cover their eggs with feathered skin known as a brood pouch, with the eggs resting on top of their feet.
“If you look at a penguin huddle in real time, you hardly see any movement at all — they are all standing very still,” said Richard Gerum, a physicist at University of Erlangen-Nuremberg in Germany and lead author of the study published in the New Journal of Physics.
But watch this huddle of shuffling penguins long enough, and there emerge distinct waves of motion through the feathered masses as one penguin takes a step and the rest follow.
It’s a way of maintaining order — something humans have trouble doing, Gerum pointed out.
“When a big human crowd is together, there can be accidents,” Gerum said. “And this is something that never happens in a penguin huddle.”
To understand how these waves begin and behave, the scientists analyzed video footage gathered on penguin colonies near the French and German research bases on Antarctica.
Just like cars do in a traffic jam, the penguins would move to fill in an empty space.
The study found that whenever a penguin moved a threshold distance of less than an inch, it triggered a traveling wave.