No matter how widely they are known, penguins always seem to fascinate people the world over. A lot has been known till date, about these pretty birds and their endearing ways. Popular culture speaks volumes about them, and they are often portrayed as being friendly, smart, and playful creatures. Some real-life accounts also describe them as being very amicable towards humans. Penguins, as it is known, are aquatic, flightless birds, inhabiting the southern hemisphere, mostly Antarctica. Numerous species of penguins are known to exist on the continent of Antarctica, each of which has certain peculiar traits that make them stand out. The Adélie penguin is one species that is found abundantly along the entire Antarctic coastline, alongside other penguin species and Antarctic fauna. The Adélie penguins may have been known since long, but it was not until 1840 that the bird was studied and described scientifically. A naturalist, Jacques Bernard Hombron and a zoologist, Honoré Jacquinot, collected specimens and published their report on Adélie penguins in 1841. Both these gentlemen were part of a French expedition led by Jules Sébastien César Dumont d'Urville, a French explorer and a naval officer. In the course of this expedition, several Antarctic islands were visited and a part of Antarctic mainland, where the Adélie penguin colonies were first visited by the humans and studied, was named after d'Urville's wife, Adéle. It was called the Adélie Land and the penguin, in turn, gets its name from this place. The Adélie penguins are the best studied among all the penguin species till date. Physical Features ✩ Adélie penguins are essentially medium-sized birds, weighing somewhere between 7 to 13 lbs. Their body weight goes on varying as the seasons change, and during the annual molt (the time when they shed their old feathers) that happens between February and March, they lose as much as half their weight. ✩ They are about 18 to 30 inches in height, which makes them one of the smallest species of penguins in the Antarctic. ✩ One of the distinguishing features of the Adélie penguins are the white rings that surround their eyes. It is not found in any other penguin species. ✩ The red beak is covered with feathers, and hence it seems to be black from a distance. ✩ The tail is brush-like and is a little longer than that of the other species. In fact, Adélie penguins (Pygoscelis adeliae) are one of the three extant species of penguins having a peculiar kind of tail. They belong to the genus Pygoscelis. The other two are the Gentoo penguins (Pygoscelis papua) and the Chinstrap penguins (Pygoscelis antarcticus). These three species of penguins are collectively called 'brush-tailed penguins' as their tail resembles a thick brush. ✩ Adélie penguins have robust and sturdy wings that help them push through the currents and facilitate swift underwater flying. ✩ On an average, an Adélie penguin can fly under water at a speed of 3 to 6 mph. However, in case of an emergency, such as protecting itself from a predator, it can increase its speed to about 15 mph. ✩ Their webbed feet and sturdy tail aid the Adélie penguins to control their movements under the surface of the water. They also use their feet and their flipper-like wings when they toboggan on ice i.e., when they lie on their bellies and slide down the ice cover. ✩ They have a uniform plumage over the entire body. It is invariably black and white in color - black on the back and while on the belly - such that the bird nearly resembles a tuxedo. ✩ The life expectancy of an Adélie penguin is about 10 to 15 years, if they do not fall prey to predators such as the lion seal and baleen whales. Habitat ✩ Around 38 colonies of the Adélie penguins are known to exist along the whole of the Antarctic coast. About 5 million of these inhabit the Ross Sea region and some 160,000 live on Cape Bird, the northern extremity of Ross Island. ✩ Adélie penguins spend nearly all their lives at sea, under the pack ice (colossal, immobile mass of ice, formed due to freezing of sea water) that covers Antarctica. ✩ They only come ashore during the breeding season. At this time, they surface on barren beaches and rocky slopes in colossal numbers. ✩ They build nests out of stones, and become highly hostile whenever another mating pair attempts to steal the stones they have collected to build their nest. ✩ Once the breeding season is over, they return to the sea to look for new breeding grounds. They form groups while returning to the sea, so that they can save themselves from predators. Behavior ✩ Adélie penguins are foragers by nature and display a highly social behavior. They are rarely found alone, and their flock is known as a 'colony'. ✩ They flock in crowded colonies, with an average colony consisting of about 250,000 pairs of birds. ✩ Adélie penguins are excellent swimmers, owing to all the adaptive features which they possess, but are a little clumsy on land. Due to their short legs, which are placed at the far back of their body, they have to walk awkwardly, in an upright position. ✩ For them, tobogganing seems like a better way to move around on land than walking. However, they seem to be quite agile when it comes to hopping over low obstacles or rocks. ✩ The main diet of the Adélie penguins comprises ice krill, Antarctic silverfish, and glacial squid. However, this varies depending on which region of the Antarctic coast the penguins inhabit. Reproduction ✩ The Adélie penguins assemble at their breeding grounds when the winter ends and the spring is about to begin. This is roughly between the months of October and November. ✩ Each pair, then occupies a certain spot and enacts some complex mating rituals, before building their nest out of stones, as mentioned before. ✩ Two eggs are laid, and in December, the warmest month in the Antarctic, the parent penguins take turns to incubate the eggs; one goes to get food, while the other stays back to warm the eggs. The parent who incubates, fasts. ✩ In the month of March, the parents and their young ones, return to the sea. ✩ Interestingly, about 80% of Adélie penguins remain faithful to their partners. Sometimes, they tend to separate, but not before at least 5 to 6 years of being together. ✩ Adélie penguins possess some unusual mating habits, the most prevalent among which are homosexuality, physical and sexual abuse of young chicks, and mating with dead females. With a total population of about 4 to 5 million birds, the Adélie penguin is not a threatened species as of now. However, the International Union for Conservation of Nature (IUCN) has included it in its Near Threatened List that pertains to species which may be threatened with extinction in the near future. Increasing human disturbance in their habitat, in the form of tourism or scientific installations, is certainly resulting in the decline in the number of their colonies.