Penguins on Stamps
Penguins (order Sphenisciformes, family Spheniscidae) are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have become flippers. Most penguins feed on krill, fish, squid, and other forms of sealife caught while swimming underwater. They spend about half of their lives on land and half in the oceans.
Although all penguin species are native to the southern hemisphere, they are not found only in cold climates, such as Antarctica. In fact, only a few species of penguin live so far south. Several species are found in the temperate zone, and one species, the Galápagos Penguin, lives near the equator.
The largest living species is the Emperor Penguin (Aptenodytes forsteri): on average adults are about 1.1 m tall and weigh 35 kg or more. The smallest penguin species is the Little Blue Penguin (Eudyptula minor), also known as the Fairy Penguin, which stands around 40 cm tall and weighs 1 kg. Among extant penguins, larger penguins inhabit colder regions, while smaller penguins are generally found in temperate or even tropical climates. Some prehistoric species attained enormous sizes, becoming as tall or as heavy as an adult human. These were not restricted to Antarctic regions; on the contrary, subantarctic regions harboured high diversity, and at least one giant penguin occurred in a region not quite 2,000 km south of the equator 35 million years ago, in a climate decidedly warmer than today.
Living species and recent extinctions
The number of extant penguin species is debated. Depending on which authority is followed, penguin biodiversity varies between 17 and 20 living species, all in the subfamily Spheniscinae. Some sources consider the White-flippered Penguin a separate Eudyptula species, while others treat it as a subspecies of the Little Penguin; the actual situation seems to be more complicated] Similarly, it is still unclear whether the Royal Penguin is merely a color morph of the Macaroni penguin. The status of the Rockhopper penguins is also unclear.
Updated after Marples (1962), Acosta Hospitaleche (2004), and Ksepka et al. (2006).
|Aptenodytes – Great penguins||King Penguin||Aptenodytes patagonicus|
|Emperor Penguin||Aptenodytes forster|
|Pygoscelis – Brush-tailed penguins||Adélie Penguin||Pygoscelis adeliae|
|Chinstrap Penguin||Pygoscelis antarctica|
|Gentoo Penguin||Pygoscelis papua|
|Eudyptula – Little penguins||Little Blue Penguin||Eudyptula minor|
|Spheniscus – Banded penguins||Magellanic Penguin||Spheniscus magellanicus|
|Humboldt Penguin||Spheniscus humboldti|
|Galapagos Penguin||Spheniscus mendiculus|
|African Penguin||Spheniscus demersus|
|Megadyptes||Yellow-eyed Penguin||Megadyptes antipodes|
|Eudyptes – Crested penguins||Fiordland Penguin||Eudyptes pachyrynchus|
|Snares Penguin||Eudyptes robustus|
|Erect-crested Penguin||Eudyptes sclateri|
|Rockhopper Penguin||Eudyptes chrysocome|
|Royal Penguin||Eudyptes schlegeli|
|Macaroni Penguin||Eudyptes chrysolophus|