Flamingos or flamingoes are a type of wading bird in the genus Phoenicopterus, the only genus in the family Phoenicopteridae.
There are four flamingo species in the Americas and two species in the Old World. A wide variety of birds have been proposed as their closest relatives, on a wide variety of evidence. As a result, flamingos are generally placed in their own order. Traditionally, the long-legged Ciconiiformes, probably a paraphyletic assemblage, have been considered the flamingos' closest relatives and the family was included in the order. Usually the ibises and spoonbills of the Threskiornithidae were considered their closest relatives within this order. Earlier genetic studies, such as those of Charles Sibley and colleagues, also supported this relationship. Relationships to the waterfowl were considered as well, especially as flamingos are parasitized by feather lice of the genus Anaticola, which are otherwise exclusively found on ducks and geese. Other scientists proposed flamingos as waders most closely related to the stilts and avocets, Recurvirostridae. The peculiar presbyornithids were used to argue for a close relationship between flamingos, waterfowl, and waders but they are now known to be unequivocal waterfowl with a peculiarly derived morphology paralleling waders and flamingos.
Flamingos often stand on one leg, the other tucked beneath the body. The reason for this behavior is not fully understood. Some species of Flamingos have the ability to have half of its body to go into a state of sleep, and when one side is rested, the flamingo will swap legs and then let the other half sleep, but this has not been proven. Recent research has indicated that standing on one leg may allow the birds to conserve more body heat, given that they spend a significant amount of time wading in cold water. As well as standing in the water, flamingos may stamp their webbed feet in the mud to stir up food from the bottom. Young flamingos hatch with greyish reddish plumage, but adults range from light pink to bright red due to aqueous bacteria and beta carotene obtained from their food supply. A well-fed, healthy flamingo is more vibrantly coloured and thus a more desirable mate; a white or pale flamingo, however, is usually unhealthy or malnourished. Captive flamingos are a notable exception; many turn a pale pink as they are not fed carotene at levels comparable to the wild. This is changing as more zoos begin to add prawns and other supplements to the diets of their flamingos.