Penguins fall into the family, Spheniscidae and the order Sphenisciformes, of aquatic, flightless birds living almost exclusively in the Southern Hemisphere, especially in Antarctica. They’ve highly adapted for life in the water, with countershaded dark and white plumage and with wings that evolved into flippers. Most penguins feed on krill, fish, squid and other forms of sea life caught while swimming underwater. They spend about half their lives on land and half in the oceans.
Although most penguin species are native to the Southern Hemisphere, they are not just found in cold climates like Antarctica. There are actually only a few species of penguin which live so far south. Several species are found in the temperate zone, and the Galapagos Penguin lives near the equator.
The largest species of penguin is the emperor penguin (Aptenodytes forsteri), which gets to an average height of 1.1 meter (3’7″) and a weight of 35 kg (77 lb) or more. The smallest penguin is the little blue penguin (Eudyptula minor), also known as the fairy penguin, which stands around 40 cm (16″) tall and weighs 1 kg (2.2 lb). Larger penguins in habit colder regions, while smaller penguins are generally found in temperate or sometimes tropical climates. Some prehistoric species of penguins attained enormous sizes, becoming as tall or as heavy as an adult human.