Penguin

The largest living species is the emperor penguin: on average, adults are about 3 ft 7 in ((1.1 m)) tall and weigh 77 lb ((35 kg)). The smallest penguin species is the little blue penguin, also known as the fairy penguin, which stands around 16 in ((40 cm)) tall and weighs 2.2 lb ((1 kg)). Among extant penguins, larger penguins inhabit colder regions, while smaller penguins are generally found in temperate climate. Some prehistoric species attained enormous sizes, becoming as tall or as heavy as an adult human. These were not restricted to Antarctic regions. The fastest species is the Gentoo Penguin, which can reach swimming speeds up to 22 mph. Unlike most birds—which lose and replace a few feathers at a time—penguins molt all at once, spending two or three weeks land-bound as they undergo what is called the catastrophic molt. All but two species of penguins breed in large colonies of up to one thousand birds. If a female Emperor Penguin's baby dies, she will often "kidnap" an unrelated chick.