Pelicans (genus Pelecanus) are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before swallowing. They have predominantly pale plumage, except for the brown and Peruvian pelicans. The bills, pouches, and bare facial skin of all pelicans become brightly coloured before the breeding season. The eight living pelican species have a patchy global distribution, ranging latitudinally from the tropics to the temperate zone, though they are absent from interior South America and from polar regions and the open ocean. Long thought to be related to frigatebirds, cormorants, tropicbirds, and gannets and boobies, pelicans instead are now known to be most closely related to the shoebill and hamerkop, and are placed in the order Pelecaniformes. Ibises, spoonbills, herons, and bitterns have been classified in the same order. Fossil evidence of pelicans dates back at least 36 million years to the remains of a tibiotarsus recovered from late Eocene strata of Egypt that bears striking similarity to modern species of pelican. They are thought to have evolved in the Old World and spread into the Americas; this is reflected in the relationships within the genus as the eight species divide into Old World and New World lineages. This hypothesis is supported by fossil evidence from the oldest pelican taxa. (Source: Wikipedia.org, CC BY-SA)