The Adélie penguin (Pygoscelis adeliae) is a species of penguin common along the entire Antarctic coast, which is their only residence.
They are among the most southerly distributed of all seabirds, along with the emperor penguin, the south polar skua, Wilson’s storm petrel, the snow petrel, and the Antarctic petrel.
During the warmer months Adélie penguins are found primarily in breeding colonies along rocky, ice-free coasts of Antarctica; colonies also occur on some islands including the South Shetland, South Orkney, and South Sandwich islands. During the winter months they migrate northward to forage in areas of open water in the pack ice.
Adélie penguins were discovered in 1840 by scientists on the French Antarctic expedition led by explorer Jules Dumont d’Urville. D’Urville named Adélie Land, in southern Antarctica, after his wife, Adéle. Scientists Jacques Hombron and Charles Jacquinot also attributed this name to the species.
The lifespan of the Adélie penguin is about 10-20 years in the wild and up to 30 years in captivity.
These penguins are mid-sized, being 46 to 71 cm (18 to 28 in) in height and 3.6 to 6 kg (7.9 to 13.2 lb) in weight.
Their back, tail, head, and face are black. They have a white belly and a white ring around their brown eyes. Their feathers cover half of their bill, which is black with an orange base. They have dull white to pink legs and feet with black soles.
Like all penguins, Adélies are excellent swimmers. Some have been recorded swimming as far as 300 km / 186 miles (150 km / 93 miles each way) to forage for their chicks.
Adélie penguins usually swim at around 8.0 km/h (5 mph). In short bursts, in order to avoid being caught by leopard seals or in pursuing prey, they can move 5-6 times that fast.
Normally, Adélie Penguins, while feeding, stay submerged for 2-3 minutes, although the longest recorded submergence is almost 6 minutes.
During those 2-3 minutes they most frequently dive to 40-50 meters (130-165 feet) but occasionally to 120-140 meters (395-460 feet) deep; the deepest recorded dive by this species is 175 meters (575 feet).
During deep dives, Adélie Penguins reduce their heart rate from 80-100 beats per minute (bpm) down to about 20 bpm.
The primary food source for Adelie penguins is krill. They also consume fish, such as lantern fish and and Antarctic silverfish. Squid, other cephalopods, and amphipods are part of their normal diet as well.
Adelie penguins have a thick layer of feathers and fat that keeps them warm. They also eat a lot to keep generating body heat.
Adélie penguins are very social birds. They are constantly interacting with others in their small group or colony.
Penguins communicate by voice and by body gestures to court a mate, recognize their mate after an absence, fend off intruders on their territory and find their chick in the crowd. These behaviors are called social displays.
Adélie Penguins can not see well in the dark. Therefore they must “follow the sun.” This means that during the winter the sun does not rise south of the Antarctic Circle, but sea ice grows during the winter months and increases for hundreds of kilometers from the shoreline, and into more northern latitudes, all around Antarctica, so that as long as the penguins live at the edge of the fast ice, there will be sunlight. As the ice recedes in the spring, they remain on the edge of it, until they are once again on the shoreline during a sunnier season. The longest treks have been recorded at 17,600 kilometers (10,900 miles).
Adélie penguins arrive at their breeding grounds in October or November, at the end of winter and the start of spring. They build nests out of the pebbles they find on dry land during spring. They choose a sloping site so that when snow melts, the water runs away from the nest.
By mid-November there are two eggs in the nest. Both parents take turns to incubate the eggs, while the other goes to sea to feed. The eggs incubate for about 36 days. The parents alternate caring for the young for about 4 weeks post-hatching, when the young enter a creche with other juvenile Adelie penguins for protection. At the age of 7–9 weeks they are ready to go to sea. Most chicks will not return to the breeding colony until they are 3–5 years of age and capable of breeding.
The Adélie is the smallest, and also the most widespread, species of penguin in the Antarctic.
Studies show that several populations are increasing. Much of this increase has been attributed to the breakup of ice shelves along certain parts of the Antarctic coast, especially on the Antarctic
Peninsula since the 1990s. The loss of ice coverage has created additional ice-free habitat for Adélie penguins.
Distributed around the Antarctic in about 161 colonies are about 2.5 million breeding pairs (5 million birds), as well as an equal number of non-breeders (5 million). The total, then, is about 10 million ‘adults.’
Many pairs will stay together for several years, but sometimes a mate will not return, so a new mate will be found.
Adélie penguins may cheekily steal rocks from their neighbours’ nests to use for their own nest construction.
Predators of Adélie penguin are leopard seals and killer whales; also polar skuas are known to prey upon their eggs along with chicks that have strayed from the group.
The penguins in the 2005 animated feature film Madagascar are presumed to be Adélie Penguins, and the main character in the 2006 film Happy Feet is an Emperor Penguin who befriends a group of Adélie Penguins with a Mexican accent.