Pelicans are a genus of large water birds comprising the family Pelecanidae. They are characterised by a long beak and large throat pouch used in catching prey and draining water from the scooped up contents before swallowing. They have predominantly pale plumage, the exceptions being the Brown and Peruvian Pelicans. The bills, pouches and bare facial skin of all species 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 as well as from polar regions and the open ocean. Fossil evidence of pelicans dates back at least 30 million years, to the remains of a beak very similar to that of modern species recovered from Oligocene strata in France.