Introduction to Adélie Penguins
|Diving Adélie penguins|
The Adélie penguin (Pygoscelis adeliae) is one of three brush-tailed penguins with a relatively long tail compared with other penguin species. It was first discovered in 1840 by a naturalist onboard one of the exploration ships of Jules Dumont d'Urville and named after d'Urville's wife, Adéle. Adélie penguins are one of several species of penguins you will see on one of our cruises to Antarctica.
Distribution and Migration of Adélie Penguins
A true antarctic penguin, the Adélie is one of two penguin species that breed only on the Antarctic continent, and population estimates put them at nearly 2.5 million birds. They generally stay within the waters of the Southern Ocean to the south of the Antarctic Convergence (the region where the great oceans—the Atlantic, the Pacific and the Indian oceans—meet in the cold waters of the Southern Ocean surrounding Antarctica). They are only rarely spotted in the South Atlantic waters surrounding the Falkland Islands and in the waters of the South Pacific near New Zealand.
Identifying Adélie Penguins—Physical Characteristics
Adélie penguins have the classic look of the tuxedoed penguin made so popular by cartoons. Their black head and back with white undersides are accented in full adult plumage by a brilliant white eye ring. Pink feet and a pink blush on the undersides of their flippers complete the look.
Juveniles are more of a blue-gray rather than black and will not have their full adult plumage until they molt in their second year. From a distance, their white throat, as compared with the black throat of the adult, is a noticeable characteristic of these younger birds.
Very young chicks have gray down with a blue-gray bill. In three weeks the down becomes browner and thicker, and in five weeks they begin to molt and fill in with the plumage of the juvenile stage.
Standing next to a person, their heads reach to a little above the knee or about 28 inches high. As with other penguins they have enormous fluctuations in their weight depending on whether it is summer—the season of plentiful food—or winter, when they live off their stored fat. The males are slightly larger than the females and can weigh between 7 and 13 pounds, while the females weigh between 6 and 12 pound
Adélie Penguin Habitat
The preferred habitats of breeding Adélie penguins are the rock slopes, ledges, cliffs and beachfronts of the continent of Antarctica—an area not known for its lush greenery.
|Adélie penguins on iceberg|
Adélie Penguin Diet
Antarctic krill, the shrimp-like crustacean that spends the summer at the surface of the Southern Ocean feeding on the lush bloom of microscopic plant life (plankton), in turn serves as the primary food of many penguin species, including Adélies. Studies of different penguin populations show that they can shift to eating more fish and squid—almost a quarter of their diet in eastern Antarctica where these other food sources are more plentiful. Generally considered shallow divers, consistently diving to no more than 150 feet, they do have the ability to dive deeper and have been recorded feeding at a depth of 577 feet.
Adélies shift their feeding distances from the colony depending on the developmental stage of, first, the eggs and, later, the chicks. While one parent incubates the eggs, the other will frequently spend up to four days 50 miles away, stocking up on rich sources of krill. After the chicks hatch, the adults tend to stay no more than 30 hours away, which generally keeps them within 12 miles of the colony.
Because the penguins breed on the Antarctic continent, the extent of the season pack ice can affect their ability to feed the chicks. If the ice remains late into the breeding season, many of the chicks do not get enough food and will not survive.
Adélie Penguin Behavior
There are a couple of signs to look for that indicate Adélie penguins are being stressed. If they raise their flippers and wave them around outstretched, if the feathers at the back of their neck rises, and/or if the white part of their eye dilates, they are exhibiting anxious behavior.
As one of the two truly Antarctic species, Adélies exhibit tobogganing and use their feet to propel themselves over snow and ice on their bellies.
|Adélie penguins on ice floe|
Adélie Penguin Breeding and Mating
Adélie Penguins do not attempt to breed until they are at least three years old and, sometimes, not until they are eight years old. To arrive at the breeding site at the beginning of October (early spring in the southern hemisphere) with the rest of the colony, they must travel over pack ice that is still in place—sometimes 50 miles of ice. Their nest is very basic; a shallow depression in the ground with outer edges lined with pebbles. In fact, some of the most amusing behavior of these penguins is watching the males while they prepare the nest by gathering rocks and pebbles from all around the area—including other Adélie nests. When the male is finished with his preparations, he stands on top, points his bill skyward and cackles. A passing female may or may not respond. When she does, they bow to each other and he spreads out the pebbles in the nest with his chest and bill and makes it comfortable for their breeding behavior. Adélies not only stay with one partner through the breeding season, but frequently for life. The breeding bond is reinforced through mutual displays—beginning with the bills of both birds first pointing downward, then skyward, with flippers stretched straight out while facing each other. They perform this behavior even when they return from feeding to relieve their partners.
Two greenish-white eggs are laid and, because of the short breeding season, there is no chance for a replacement clutch if the first is disturbed by predators. Both parents incubate for 32–37 days. After the chicks are 2–3 weeks old, both parents leave to feed at the same time in order to keep up with the demand, while the young chicks gather in a crèche—a grouping of all the chicks in the colony. They take refuge from the elements in the warmth of their combined down coats and have increased shelter from predators while waiting for their parents to return with food.
Adélie Penguin Social Behavior
Adélies exhibit a number of aggressive behaviors, all of which occur in the vicinity of their nests:
- Bill-jousting—wrestling between birds at adjacent nests
- Bill-to-axilla—rotating their heads from side to side
- Alternate stare—arching their necks while twisting their heads back and forth so that alternate sides of the face can be seen
- Head tuck—tucking their heads under an outstretched flipper
on large iceberg
Adult with chick
A gathering of
More Resources For Information On Adélie Penguins
Adélie penguin monitoring program administered by the Australia Antarctic Division
Adélie Penguin: Bellwether of Climate Change by David Ainley, Columbia University Press
Hear the various sounds of Adélie penguins and what scientists believe these sounds mean.
University of Washington's Center for Penguins as Ocean Sentinels