Endemic to Antarctica, the emperor penguin is the biggest such bird. It is the only penguin that breeds during the frigid winter: trekking 50–120 kilometers over the ice into the continental interior to form huge breeding colonies. When bitter cold comes, thousands tightly huddle together to keep from freezing to death.
“Penguins in a huddle are packed so tightly that individual movements become impossible.” ~ German physicist Daniel Zitterbart
Holding precious eggs between their legs, huddled fathers-to-be travel 5–10 centimeters every 30–60 seconds. When one penguin moves a single step, others must also move to close the open space and stay warm. Each step creates a cascading wave of movement. If 2 waves travel toward each other, they merge. To stay warm, gaps just 2 centimeters wide instigate a reorganization.
“If you look at the huddle in real-time, it seems very steady – every penguin seems to stay at a fixed location.” ~ German zoologist Richard Gerum
“Individual penguins do not change their position relative to their neighbors, and they do not force their way in or out of a huddle.” ~ Daniel Zitterbart
The coordinated wave movement allows optimal warmth for the entire huddle by circulating penguins from the colder outer region into the warmer inner region, and vice-versa.
“They definitely have to be altruistic in their behavior to survive.” ~ Daniel Zitterbart
Emperor penguin huddle movement is an example of complex social behavior from precocious knowledge, as there is no way this slow-motion ballet is learned; and it is impossible to imagine how such savvy could be imparted by DNA.