Flamingos usually stand on one leg while the other is tucked beneath their bodies. The reason for this behaviour is not fully understood. One theory is that standing on one leg allows the birds to conserve more body heat, given that they spend a significant amount of time wading in cold water. However, the behaviour also takes place in warm water and is also observed in birds that do not typically stand in water. An alternative theory is that standing on one leg reduces the energy expenditure for producing muscular effort to stand and balance on one leg. A study on cadavers showed that the one-legged pose could be held without any muscle activity, while living flamingos demonstrate substantially less body sway in a one-legged posture. As well as standing in the water, flamingos may stamp their webbed feet in the mud to stir up food from the bottom.
Flamingos are capable flyers, and flamingos in captivity often require wing clipping to prevent escape.
Flamingos in flight at Rio Lagartos, Yucatán, Mexico
Young flamingos hatch with greyish-red 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 colored, thus a more desirable mate; a white or pale flamingo, however, is usually unhealthy or malnourished. Captive flamingos are a notable exception; they may turn a pale pink if they are not fed carotene at levels comparable to the wild.
The greater flamingo is the tallest of the 6 different species of flamingos, standing at 3.9 to 4.7 feet with a weight up to 7.7 pounds, and the shortest flamingo species (the lesser) has a height of 2.6 feet and weighs 5.5 pounds. Flamingos can have a wingspan as small as 37 inches to as big as 59 inches.