Everyday They’re Shufflin’ – Emperor Penguins’ Huddles

A new model proposed by French and German scientists suggests that the shifts and movements of an emperor penguins’ huddle resemble those of traffic jams. Pre-existing video recordings had shown wave-like patterns, but whether these waves always originated from the same individual, and how the resulting ripples extended, was unclear.

This model, published in the New Journal of Physics on December 16, is based on images taken in 2005 of two emperor penguin colonies at Pointe Géologie and Atka Bay, Antarctica. Time-lapse images were taken every 1.3 seconds for 4 hours, creating films that show the waves occurring every 35-55 seconds. After analyzing these movements, and creating analogous computer simulations, the scientists are able to propose that that the wave movements are not dependent on a hierarchical social structure and can be started by any individual penguin moving as little as 2cm. This model would also explain how two huddles merge, and demonstrate how the waves seamlessly extend to include the new individuals.

These huddles are typically formed by males during the winter, when they are left to incubate their eggs for as long as two months while the females return to the ocean to feed. During this time they have no food and must survive some of the harshest conditions on the planet, with temperatures as low as -50 C and wind speeds sometimes reaching 200 km/h. Conserving energy is therefore critical, and the penguins form huddles in order to increase body temperature and protect against the elements. By modeling how the penguins move within these huddles, we can begin to understand how the penguins achieve and maintain a maximally dense structure.

The full article can be read here: http://iopscience.iop.org/1367-2630/15/12/125022/pdf/1367-2630_15_12_125022.pdf