The Adelie Penguin is the smallest and most widely distributed species of Penguin in the Southern Ocean and is one of only two species of Penguin found on the Antarctic mainland (the other being the much larger Emperor Penguin). The Adelie Penguin was named in 1840 by French explorer Jules Dumont d'Urville who named the Penguin for his wife, Adelie. Adelie Penguins have adapted well to life in the Antarctic as these migratory Birds winter in the northern pack-ice before returning south to the Antarctic coast for the warmer summer months.
The Adelie Penguin is one of the most easily identifiable Penguin species with a blue-black back and completely white chest and belly. The head and beak of the Adelie Penguin are both black, with a distinctive white ring around each eye. The strong, pink feet of the Adelie Penguin are tough and bumpy with nails that not only aid the Adelie Penguin in climbing the rocky cliffs to reach its nesting grounds, but also help to push them along when they are sliding (rowing) along the ice. Adelie Penguins also use their webbed feet along with their small flippers to propel them along when swimming in the cold waters.
Adelie Penguins are strong and capable swimmers, obtaining all of their food from the sea. These Penguins primarily feed on krill which are found throughout the Antarctic ocean, as well as Molluscs, Squid and small Fish. The record of fossilised eggshell accumulated in the Adelie Penguin colonies over the last 38,000 years reveals a sudden change from a Fish-based diet to Krill that started two hundred years ago. This is thought to be due to the decline of the Antarctic Fur Seal Seal in the late 1700s and Baleen Whales in the twentieth century. The reduction of competition from these predators has resulted in there being an abundance of Krill, which the Adelie Penguins are now able to exploit as an easier source of food.
Adelie Penguins return to their breeding grounds during the Antarctic summer months of November and December. Their soft feet are well designed for walking on land making the trek to it's nesting ground much easier as the Penguin fasts during this time. Adelie Penguin pairs mate for life in large colonies, with females laying two eggs a couple of days apart into a nest built from rocks. Both the male and female take it in turns to incubate their eggs while the other goes off to feed, for up to 10 days at a time. The Adelie Penguin chicks have an egg-tooth which is a bump on the top of their beaks, which helps them to break out of the egg. Once hatched, the parents still take it in turns to look after their young while the other goes off to gather food. After about a month, the chicks congregate in groups called crèches and are able to fend for themselves at sea when they are between 2 and 3 months old.
Adelie Penguins inhabit one of the coldest environments on Earth and so have a thick layer of fat under their skin helping to keep them warm. Their feathers help to insulate them and provide a waterproof layer for extra protection. The Adelie Penguin is a highly efficient hunter and is able to eat up to 2kg of food per day, with a breeding colony thought to consume around 9,000 tonnes of food over 24 hours. The flippers of the Adelie Penguin make them fantastic at swimming and they can dive to depths of 175 meters in search of food. Adelie Penguins do not have teeth as such but instead have tooth-shaped barbs on their tongue and on the roof of their mouths. These barbs do not exist for chewing but instead assist the Penguin to swallow slippery prey.