Which penguin species forms large huddles to conserve heat during Antarctic winters?

The emperor penguin is the penguin species that forms large huddles to conserve heat during Antarctic winters.

Emperor penguins breed during the Antarctic winter, when temperatures can fall far below freezing and powerful winds increase heat loss. Males remain on the sea ice to incubate a single egg while females travel to sea to feed. Huddling lets the birds share warmth and reduce the energy each one spends maintaining body temperature.

The huddle is constantly changing rather than being a fixed cluster. Penguins gradually move from the cold outer edge toward the warmer center, allowing others to take their place. This rotation spreads the benefits across the group and helps males survive their long breeding fast.

Emperor penguins are often confused with king penguins, which are similar in appearance. King penguins also form groups, but emperor penguins are the species especially associated with massive winter huddles and breeding on Antarctic sea ice. Their large body size, dense plumage, and specialized blood-flow control provide additional insulation.