Antarctic Animals: Penguins, Seals and Life Around the Ice

Why are there no polar bears or land mammals in Antarctica?

Antarctica has been isolated by the Southern Ocean for tens of millions of years, and about 98% of the continent is buried under ice, so there is almost nothing on land for a large animal to eat. All the food is in the sea, which is why every Antarctic bird and mammal is a swimmer or a seabird.

Polar bears evolved from brown bears in the Arctic and have never crossed the tropics to reach the far south; see do polar bears live in Antarctica? for the full story. Without land predators such as bears or foxes, penguins and seals can nest and rest on open ice, and many show little fear of people.

1. Emperor penguin

The emperor penguin is the largest penguin, standing about 1 m (39 in) tall and weighing 22–45 kg (49–99 lb). It is the only penguin that breeds during the Antarctic winter. After the female lays her single egg, the male balances it on his feet under a fold of skin and incubates it for just over two months, eating nothing while temperatures fall to about −40 °C (−40 °F) and winds blow at up to 144 km/h (89 mph).

Males survive by huddling in tightly packed groups that slowly shuffle so each bird takes turns in the warm center. Emperors are also superb divers: one was recorded at 564 m (1,850 ft) on a dive lasting almost 22 minutes.

2. Adélie penguin

The Adélie penguin is the classic black-and-white penguin with a white ring around each eye. It is 70–73 cm (28–29 in) long and lives all around the Antarctic coast, along with the emperor. It was named after Adélie Land, which the French explorer Jules Dumont d’Urville named after his wife, Adèle. Adélies build nests from small stones, and pebbles are so valuable that birds often steal them from their neighbors.

3. Chinstrap and gentoo penguins

The chinstrap penguin is named for the thin black line under its chin, which looks like a helmet strap. It breeds mainly on the Antarctic Peninsula and nearby islands. A 2023 study found that nesting chinstraps take more than 10,000 microsleeps a day, each lasting about 4 seconds, adding up to around 11 hours of sleep.

The gentoo penguin, recognized by its orange bill and white patch over each eye, also breeds on the peninsula and sub-Antarctic islands. It is the fastest swimming penguin, reaching up to 36 km/h (22 mph) underwater. To see where all penguin species live, read where do penguins live?

4. Weddell seal

The Weddell seal lives on the fast ice attached to the coast and breeds farther south than any other mammal. Adults are 2.5–3.5 m (8.2–11.5 ft) long and weigh 400–600 kg (880–1,320 lb). In winter they stay in the water under the ice, which is warmer than the air above, and keep breathing holes open by scraping the ice with their teeth. They can dive to about 600 m (2,000 ft) and stay under for up to an hour, and their eerie underwater trills can be heard through the ice.

5. Leopard seal

The leopard seal is the top predator among Antarctic seals. It is 2.4–3.5 m (7.9–11.5 ft) long and weighs 200–600 kg (440–1,320 lb), with females larger than males. It has a huge, reptile-like head and spotted throat, and it hunts penguins, fish, squid and the pups of other seals. Its back teeth lock together into a sieve, so it can also strain krill from the water.

6. Crabeater seal

Despite its name, the crabeater seal eats almost nothing but Antarctic krill, which it strains through elaborately lobed teeth. It lives on the pack ice all around Antarctica and is by far the most numerous seal in the world, with estimates ranging from at least 7 million to as many as 75 million animals. Many crabeaters carry long scars from escaping leopard seals when they were young.

7. Southern elephant seal

The southern elephant seal is the largest seal on Earth. Adult males weigh 3,000–3,700 kg (6,600–8,200 lb) and grow up to 4.6–5.8 m (15–19 ft) long, while females weigh 350–900 kg (770–1,980 lb). It breeds on sub-Antarctic islands such as South Georgia and Kerguelen and feeds on squid and fish, often diving 400–1,000 m (1,300–3,300 ft) deep for 20 minutes or more at a time.

8. Whales of the Southern Ocean

In summer, the Southern Ocean becomes a feeding ground for great whales. Antarctic blue whales, the largest animals that have ever lived, humpbacks, fin whales and Antarctic minke whales come south to eat krill, then most migrate to warmer waters to breed. The humpback whale is among the most familiar, often feeding close to the Antarctic Peninsula. Commercial whaling in the 20th century killed hundreds of thousands of whales in these waters, and the blue whale has recovered only slowly.

The orca is the top predator of the region. Several types live around Antarctica, each with its own diet: some hunt minke whales, others eat fish, and one type works as a team to make waves that wash seals off floating ice.

9. Antarctic krill

Antarctic krill are small, shrimp-like crustaceans that grow to about 6 cm (2.4 in) and live up to six years. They gather in swarms that can hold 10,000–30,000 animals in a single cubic meter of water. Their total weight is estimated at hundreds of millions of tonnes, making them one of the most abundant animals on the planet. Krill graze on microscopic algae, including algae growing under sea ice, and in turn feed whales, seals, penguins, fish and seabirds, so almost the whole Antarctic food web depends on them.

10. Icefish

Icefish are among the strangest fish in the sea. They are the only known backboned animals that have no hemoglobin in their blood as adults, so their blood is clear rather than red. They manage without it because icy polar water holds plenty of oxygen, and they have large hearts and wide blood vessels that pump a lot of blood. Like other Antarctic notothenioid fish, they also make antifreeze proteins that stop ice crystals from growing inside their bodies in water at about −1.8 °C (28.8 °F). In 2021, scientists found a breeding colony of an icefish species in the Weddell Sea with an estimated 60 million nests spread across about 240 km² (92 sq mi) of seafloor.

11. Snow petrel

The snow petrel is a pure white seabird about the size of a pigeon, with a black bill and dark eyes. It nests farther south than any other bird, on rocky peaks poking through the ice far inland, and it is one of only three birds ever seen at the geographic South Pole. When an intruder comes too close, it defends its nest by spitting a smelly, waxy stomach oil.

12. Wandering albatross

The wandering albatross has the longest wingspan of any living bird, up to 3.7 m (12 ft) and averaging about 3.1 m (10 ft). It breeds on sub-Antarctic islands such as South Georgia and roams the Southern Ocean almost without flapping, gliding on the strong westerly winds. Some birds fly around the whole Southern Ocean several times in a year. It is listed as Vulnerable, mainly because many drown after taking baited hooks from longline fishing boats.

13. South polar skua

The south polar skua is a brown, gull-like seabird that breeds along the Antarctic coast. It steals food from other birds and preys on penguin eggs and chicks, so skuas are often seen patrolling the edges of penguin colonies. Along with the snow petrel and the Antarctic petrel, it is one of the few birds recorded at the South Pole.

14. Antarctic midge and other tiny land animals

The largest animal that lives its whole life on land in Antarctica is the Antarctic midge, a flightless insect only 2–6 mm (0.08–0.24 in) long. Its larvae survive being frozen in winter and dried out in summer, and the species has one of the smallest known insect genomes. Springtails, mites, roundworms and tardigrades also live in patches of moss and lichen, especially on the Antarctic Peninsula.

How Antarctic animals survive the cold

Antarctic seals and whales are wrapped in thick blubber, while penguins have a layer of fat under very dense, overlapping feathers that trap warm air. Many animals have a heat exchange system in their flippers, legs or feet, where warm blood flowing out passes cold blood flowing back and warms it before it reaches the body. Living in the sea also helps, because seawater never gets colder than about −1.8 °C (28.8 °F), while winter air on land can be far colder.

Threats to Antarctic wildlife

Climate change is the biggest long-term threat. Emperor penguins need stable sea ice until their chicks grow waterproof feathers, and in late 2022 early ice breakup caused breeding failure at four of five known colonies in the Bellingshausen Sea region. Shrinking sea ice can also reduce krill, the food at the base of the web. Krill fishing is managed by an international commission set up in 1982, and the Antarctic Treaty protects wildlife on the continent. Since late 2023, the H5N1 bird flu has reached the region, and scientists are monitoring seal and penguin colonies closely.

The far north has a very different set of animals; compare this list with our guide to Arctic animals.