Penguins move in sync to keep warm, study shows By Los Angeles Times, adapted by Newsela staff Jan. 15, :00 AM

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1 Penguins move in sync to keep warm, study shows By Los Angeles Times, adapted by Newsela staff Jan. 15, :00 AM A group of emperor penguins pictured on Antarctica s Ross Island. 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, the congestion is probably keeping you alive. Scientists studying huddles of emperor penguins in Antarctica have discovered that waves of movement travel through gathered masses of flightless birds. It s similar to the waves moving through cars stuck on the freeway during rush hour. But penguins move in ways that maximize the huddle s density and keep the birds warm as they incubate their eggs. Emperor penguins are the only large, complex animal species that breeds during the Antarctic winter. They face freezing winds that blow as fast as 124 miles per hour 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. Small Moves Start Big Waves At first glance, the penguins may not appear to move much. The males probably can t run anywhere in a rush, in any case: The fathers-to-be cover their eggs with feathered skin known as a brood 1

2 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. He is a physicist at the University of Erlangen-Nuremberg in Germany and first author of the study published in the New Journal of Physics. But watch this huddle of shuffling penguins close enough and long enough. You will see distinct waves of motion emerge 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. Penguin Traffic Control 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. But unlike cars in a traffic jam, any penguin can initiate movement, whether they re in the front, to the back or to the side. (A car trying to initiate movement from the back would end up rear-ending the car in front of it.) The waves, said a previous study, travel through the huddle at regular intervals of 35 to 55 seconds. The new study found that whenever a penguin moved a threshold distance of about 2 centimeters, it triggered one of these traveling waves. The 2-centimeter threshold is no accident: That s roughly twice the thickness of a penguin s properly fluffed layer of insulating feathers. This suggests that the penguins touch each other only slightly when standing in a huddle, the study authors wrote. The penguins avoid compressing the feather layer so as to maximize the huddle density without compromising their own insulation. Keep Your Distance, But Not Too Much So if a penguin moves too far away allowing heat to escape the penguin next to it moves closer. But if a penguin moves too close to another crushing its neighbor s insulating layer of feathers this will also cause the neighbor to move. Such waves aren t determined by a penguin s rank in the group. Any penguin can start them, and 2

3 they re a product of a simple set of rules governing the space between each penguin and its immediate neighbors. And yet, these tiny movements can add up to a large-scale, complex order. It s similar to the impressive patterns seen in schools of fish, flocks of birds or swarms of ants. These rules allow the penguins to stay organized, to maximize heat conservation and even to merge two smaller penguin huddles together. So although these emperor penguins don t dance like the characters in the movie Happy Feet, they still perform some pretty fancy footwork. 3

4 Quiz 1. Select the paragraph from the first part of the article which provides the most support for the idea that penguins need the huddle to survive in a harsh environment. 2. Select the paragraph from the section Keep Your Distance, But Not Too Much which provides the most specific information about the distances penguins need to keep. 3. According to the article, how is a traffic jam connected to the penguin huddle? (a) Both follow a specific, organized pattern. (b) Both are created by random movements. (c) Both consist of moving to fill an empty space. (d) Both can be caused by any movement from any spot. 4. According to the article, a traffic jam is different from a penguin huddle in all of the following ways EXCEPT: (a) There are accidents in traffic, but not so in a penguin huddle. (b) People are unhappy with traffic congestion but male penguins rely on huddle congestion. (c) A car behind another car cannot initiate a wave, but a penguin behind another penguin can do so. (d) Waves of traffic happen about 20 to 30 seconds, but waves in a penguin huddle are every 35 to 55 seconds. 4

5 Answer Key 1. Select the paragraph from the first part of the article which provides the most support for the idea that penguins need the huddle to survive in a harsh environment. 3 Emperor penguins are the only large, complex animal species that breeds during the Antarctic winter. They face freezing winds that blow as fast as 124 miles per hour 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. 2. Select the paragraph from the section Keep Your Distance, But Not Too Much which provides the most specific information about the distances penguins need to keep. 12 So if a penguin moves too far away allowing heat to escape the penguin next to it moves closer. But if a penguin moves too close to another crushing its neighbor s insulating layer of feathers this will also cause the neighbor to move. 3. According to the article, how is a traffic jam connected to the penguin huddle? (a) Both follow a specific, organized pattern. (b) Both are created by random movements. (c) Both consist of moving to fill an empty space. (d) Both can be caused by any movement from any spot. 4. According to the article, a traffic jam is different from a penguin huddle in all of the following ways EXCEPT: (a) There are accidents in traffic, but not so in a penguin huddle. (b) People are unhappy with traffic congestion but male penguins rely on huddle congestion. (c) A car behind another car cannot initiate a wave, but a penguin behind another penguin can do so. (d) Waves of traffic happen about 20 to 30 seconds, but waves in a penguin huddle are every 35 to 55 seconds. 5