Penguins are perhaps some of the most popular and best-loved of all birds. They appear throughout human culture, and are featured in children’s books, in magazines, cartoons, and in the movies; indeed, March of the Penguins was one of the highest-grossing documentary films of all time. When people think of penguins, they think of the Antarctic, and imagine a pristine wilderness occupied by numerous sleek, fat, well-fed penguins.
When encountered in the wild, penguins can seem querulous, angry, and argumentative. After breeding penguins moult their feathers they are anything but sleek. In fact, they cannot enter the water again until they have grown new feathers.
There are 18 species of penguins and they do not all live in the Antarctic. Many species are classified as Endangered or Vulnerable by the International Union for Conservation of Nature. These at-risk populations live mainly in South America, Africa, New Zealand, or in the sub-Antarctic.
Seven species of penguins are found in the Antarctic: Adélies (Pygoscelis adeliae), chinstraps (Pygoscelis antarctica), gentoos (Pygoscelis papua), king (Aptenodytes patagonicus), emperors (Aptenodytes forsteri), macaronis (Eudyptes chrysolophus), and southern rockhoppers (Eudyptes chrysocome).
Penguins spend the majority of their life at sea, diving for small fish, squid, and crustaceans, such as Antarctic krill (Euphausia superba), on which they feed. They return to land to reproduce and breed in colonies. The largest known penguin colony is on Zavadovski in the South Sandwich Islands where a million pairs of chinstraps breed annually. Feeding so many penguins requires enormous amounts of marine prey.
In the Antarctic and sub-Antarctic, Adélie, chinstrap, gentoo, macaroni, and emperor penguins depend upon Antarctic krill, particularly during the breeding season. Understanding how penguins find their food and how they compete with seals, whales, and other seabirds, as well as how fishing activities impact their prey sources, is vitally important if penguin populations are to thrive.