Adélie penguins
Scientific name: Pygoscelis adeliae
Physical description and related species
Adélie penguins were named in 1930 by the French explorer Jules Dumont d'Urville for his wife Adélie.
The penguins are 46 to 75 cm long and 3.9 to 5.8 kg in weight. They are distinguished by the white ring surrounding the eye. Males and females are of similar size and difficult to tell apart.
Adélie penguins are closely related to two other penguins, the Gentoo (Pygoscelis papua) and the Chinstrap (Pygoscelis antarctica).
Distribution and abundance
Adélie penguins breed around the entire coast of Antarctica in places where there is exposed rock. Their main predators are leopard seals. Skuas take eggs and chicks from breeding colonies.
Conservation status: least concern
Breeding
After spending the winter in the pack ice, Adélie penguins move into their breeding colonies on land. They begin arriving at Béchervaise Island on about the 18th of October. They return to the same nest and the same mate as in the previous year if they can. They build nests out of small rocks, then mate and lay two eggs by mid-November.
The male and female take turns incubating the eggs over the next 34 days until the chicks hatch. Each off-duty bird spends 15-20 days at sea feeding to regain the weight it has lost during courtship. Once chicks hatch (mid to late December) the parents alternate guard and feeding duties. They swap over every couple of days. The adult birds head out to sea to catch krill, fish and amphipods which they regurgitate for the chicks.
The chicks on Béchervaise Island have been shown to grow by 80 grams per day. When chicks are three weeks old (mid January) they are big enough to be left alone, allowing both parents to simultaneously collect food for them. The chicks group together in 'crèches' for protection and warmth.
At 7-9 weeks of age (mid to late February) the chicks have replaced their down with adult feathers and are ready to go to sea. Once they depart the breeding colonies, most will not return until they are old enough to breed (three to five years of age). Adélie penguins have a life expectancy of 10 to 20 years.
Diet and feeding
Adélie penguins feed mainly on krill (Euphausia crystallorophias and E. superba), but will also eat fish, squid and other crustaceans.
Breeding adults travel between five and 120 km offshore to catch food for their chicks. Feeding trips range from five to 72 hours in duration.
Adélie penguins are capable of diving to depths of up to 175 m but usually feed within the upper 70 m of the water column.
