Emperor penguins are known to huddle together during the winters to retain body heat and keep warm. They are also known to move in waves and scientists have now used a mathematical model to explain this movement.
Using a mathematical model used to study traffic jams, flocks of birds and schools of fish, scientists have found that an individual penguin needs to move only 2 centimeters in any direction to set off a chain reaction.
The model is used to predict how autonomous individuals can incrementally move step-by-step within a tightly packed huddle, much like cars inching forward in a traffic jam.
But unlike traffic jams, the movement of the penguins could be initiated by a single penguin as soon as the gap between two penguins was greater than the "threshold distance" of 2 cms. This threshold distance was calculated to be twice the thickness of a penguin's compressive feather layer.
This suggests that the penguins touch each other only slightly, in order to maintain a fluffy feather layer, which provides insulation in the cold Antarctic weather.
"We were really surprised that a travelling wave can be triggered by any penguin in a huddle, rather than penguins on the outside trying to push in," said researcher Daniel Zitterbart. The findings are published in the New Journal of Physics.
Earlier research used time-lapse videos to ascertain that the massive groups did not stay still and moved every 30 to 60 seconds. But they found that all the penguins moved in a synchronized manner, much like a wave, never understanding how these movements were initiated.
[New Journal of Physics] [Science World Report]