Thousands of penguins huddle in a slow-moving swirl to survive -50°C winds

Emperor penguins breed through the Antarctic winter by packing into huddles of thousands, each bird taking turns at the freezing outer edge before shuffling back toward the warmer centre. The huddle raises the temperature at its core far above the outside air, and the whole mass constantly reorganises so no single bird is stuck outside for long. It's one of the only ways any animal survives Antarctic winter without migrating.

— British Antarctic Survey, Emperor penguin — Species research summary