Penguins are birds that cannot fly. Early penguins lived in warm seas, so penguins did not begin in the cold. Fossil bones suggest penguins began in the Zealandia region, the land around New Zealand. A fossil penguin named Kumimanu biceae stood about 1.65 meters tall and weighed about 100 kilograms. The Kumimanu fossil is about 55 to 60 million years old, close in age to the oldest known penguins. The name Kumimanu, given to a giant fossil penguin, means "monster bird" in Maori. The emperor penguin is the biggest penguin. A grown emperor penguin stands about 1.1 meters (45 inches) tall. A big emperor penguin can weigh about 40 kilograms (88 pounds). Penguins as big as or bigger than emperors lived between about 50 and 20 million years ago.

Only two kinds of penguin, the emperor and the Adelie, are true residents of the Antarctic continent. Not every penguin lives in snow and ice. The Galapagos penguin lives on islands on the equator, and it is the only wild penguin found north of the equator. Galapagos penguins lay eggs in cracks and caves in lava rock near the sea. As of November 2026, the Galapagos penguin is endangered. As of November 2026, only a few thousand Galapagos penguins are left; counts differ, from 1,200 to about 2,000-3,000. An African penguin weighs about 3.1 kilograms (6.8 pounds) on average. As of November 2026, African penguins are critically endangered, and their numbers have been falling since the early 1900s.

Emperor penguins breed in the middle of the Antarctic winter. Emperor penguins build up fat before winter and live on it while they fast during breeding. Emperor penguins breed on sea ice and also hunt along its edge, so they depend on it. Most emperor colonies sit on fast ice, sea ice that is frozen to the land or to grounded icebergs. Emperor penguins rely on stable fast ice for about eight months of the year, from breeding until chicks leave. Early sea ice breakup can be deadly to chicks: in 2016 more than 10,000 emperor chicks died at one colony when ice dissolved too soon.

As of April 2026, satellite images show about a 10 percent loss of emperor penguins across Antarctica between 2009 and 2018. As of November 2026, climate change is the main cause of the fall in emperor penguin numbers. As of November 2026, emperor penguins are officially listed as at risk of extinction: threatened under the United States Endangered Species Act and Endangered on the IUCN Red List. As of November 2026, the main reason is shrinking sea ice, which is expected to keep shrinking for decades. At least one emperor penguin colony has all but disappeared as the sea ice changed.

Words to know

• Zealandia: New Zealand region
• fossil: old remains
• equator: Earth's middle line
• endangered: nearly gone
• lava: volcano rock