Penguins are a group of aquatic flightless birds from the family Spheniscidae of the order Sphenisciformes. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapted for life in the ocean water, penguins have countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill, fish, squid and other forms of sea life which they catch with their bills and swallow whole while swimming. A penguin has a spiny tongue and powerful jaws to grip slippery prey.
A group of emperor penguins (Aptenodytes forsteri) in Antarctica
Adélie penguin (Pygoscelis adeliae) feeding young. Like its relatives, a neatly bi-coloured species with a head marking.
Magellanic penguins (Spheniscus magellanicus). The closed neck collar denotes this species.
Southern rockhopper penguin (Eudyptes chrysocome) displaying its distinctive crest
A water bird, alternatively waterbird or aquatic bird, is a bird that lives on or around water. In some definitions, the term water bird is especially applied to birds in freshwater ecosystems, although others make no distinction from seabirds that inhabit marine environments. Some water birds are more terrestrial while others are more aquatic, and their adaptations will vary depending on their environment. These adaptations include webbed feet, beaks, and legs adapted to feed in the water, and the ability to dive from the surface or the air to catch prey in water.
Geese and ducks are just two types of water birds, which include seabirds, shorebirds, waterfowl, and numerous other forms of birds.
A yellow-billed loon, a diving bird in the order Gaviiformes, swimming on a lake in the northern area of Alaska, United States
The Brown pelican (Pelecanus occidentalis) has an enlarged throat pouch to aid it in feeding on schools of small fish. It is a member of the order Pelecaniformes, which also contains the herons, bitterns, and ibises
Pacific black ducks, one of the dabbling ducks, feeding in a wetland
