Order Spenisciformes Introduction Penguins are perhaps among the best-known birds on Earth, although ironically at first glance they scarcely seem to belong to that class. All are built around a similar body pattern, being flightless with long flippers instead of wings and having webbed feet. While appearing somewhat clumsy on land, in the water they are superb, agile and fast swimmers. They prey on marine invertebrates such as krill and small squid, as well as small fish depending on the species of the penguin. In turn they are predated on by larger marine mammals such as seals and killer whales.
Most penguins are extremely social animals and live in colonies of vast numbers.
This also has some practical importance, since Emperor Penguins at least use this density of numbers to huddle together against the cold during those times when they await the return of their mates with food. Normally one or two eggs are laid, but in times of hardship usually only one chick will survive, the stronger receiving any food available. Despite this apparent hardship and the threat to penguins from environmental pollution and global warming, this group of birds is for the most part quite healthy in numbers, although some local declines, eg in the Falkland Islands, have been reported. They are entirely located in the southern hemisphere, being distributed mainly around Antarctica and the South Atlantic but also found in South Africa, South America, and Australia and New Zealand. There are six genera of penguins, comprising a total of 16-18 species.