Emperor penguins

The largest of the penguin species, the emperor grows up to 1.15 metres tall and weighs up to 40 kg. They are very deep divers, often plunging down to about 250 metres with dives lasting on average 3–6 minutes. Their menu is varied and includes fish, krill and squid.

A truly a hardy animal, it is the only warm-blooded creature that breeds during the Antarctic winter, surviving blizzards, darkness and wind chill equivalent of temperatures as low as -60 C. Every year around late March, adult emperor penguins leave the pack ice and may walk up to 200 km over its frozen surface to their breeding sites. They need stable, long-lasting fast ice on which to breed.

In May or June, the females lay one egg and then make the long walk back to open water, eating again for the first time in about two months. In the meantime, the egg is kept on the feet of the father, protected under the layers of feathers and fat of its abdomen.

During the next two months, the father fasts while keeping watch until its chick hatches. Miraculously, at that time the mother returns with food. By that time of year (July-August), food can then be obtained more easily because adjacent ocean areas have been swept free of sea ice by strong winds. Read more here.

Four Emperor penguin (Aptenodytes forsteri) chicks with an adult at Snow Hill Island colony. Antarctica
© naturepl.com / Bryan and Cherry Alexander / WWF

Adelie penguins

Named in the 1800’s by the French explorer Jules Dumont d'Urville for his wife Adéle, these penguins stand 46-75 cm high and weigh from 3.9-5.8 kg. They eat mostly krill but fish, squid and amphipods also appear on their menu. The Adélie penguin needs access to sea ice and open water for foraging but only breeds on land without ice. Although Antarctica is big, less than 1% of its land is ice-free.

An ideal Adélie penguin breeding site needs to be accessible from the sea with minimal walking; have a gently sloping beach free of snow, ice or meltwater; and have a plentiful supply of little pebbles that these penguins use to build their nests. The pebbles keep eggs and small chicks out of puddles and mud formed after . In recent decades, populations of Adélie penguins have decreased dramatically along the northwestern coast of the Antarctic Peninsula due to warmer temperatures and decreasing sea ice. Read more here.

Adelie penguin (Pygoscelis Adeliae) on glacial ice along the western Antarctic Peninsula, Southern Ocean
Adelie penguin (Pygoscelis Adeliae) on glacial ice along the western Antarctic Peninsula, Southern Ocean © naturepl.com / Steven Kazlowski / WWF

Become a virtual penguin scientist

Help monitor penguins in remote Antarctic regions. Scientists have travelled to some of the coldest areas on the planet to learn more about penguin populations. Help by adding explanations to their images of wildlife in Antarctica and the Southern Ocean. Visit www.penguinwatch.org