Penguins and their noisy world.

Penguins identify their mate or chick by an acoustic signal, the display call. This identification is realized in a particularly constraining environment: the noisy world of a colony of thousands of birds. To fully understand how birds solve this problem of communication, we have done observations, acoustic analysis, propagation and playback experiments with 6 species of penguins studied in the field. According to our results, it appears that penguins use a particularly efficient "anti-confusion" and "anti-noise" coding system, allowing a quick identification and localization of individuals on the move in a noisy crowd.