Known for their long legs and striking bright pink feathers, flamingos are wading birds found in the Americas, Asia, Africa and parts of southern Europe, although they have been known to flourish as far north as Germany.
The name flamingo comes from the Portuguese/Spanish word ‘flamengo’ which translates to ‘flame-coloured’ in relation to their vibrant feathers, however, they aren’t actually born pink. Instead, when flamingo chicks hatch they have a dull grey colouration to their feathers.
The reason why flamingos are pink is down to their diet of algae, shrimps and crustaceans. The wetland habitats they call home are packed with blue-green algae, which despite their name are actually red or orange in colour due to a chemical known as beta carotene. This chemical has a red-orange pigment in it known as carotenoid, which is also found in carrots, sweet potatoes and spinach.
Once eaten, enzymes in the flamingo’s digestive system break down the beta carotene and the red-orange pigments are absorbed by the fat in its liver. These fats are then deposited in the flamingo’s feathers and skin as it grows. As their diet is almost exclusively from sources rich in beta carotene, flamingos gradually become pink.
The colouration of flamingos can vary because carotenoid levels in algae and crustaceans also vary across the world. Flamingo species found in the Caribbean are often bright red or orange, while those in drier areas tend to be paler pink in colour. Without a high enough concentration of beta carotene-rich food, the pink feathers would moult away and new paler feathers would start to grow.
Although the sight of a colourful flamingo is a familiar one, there are a number of ways they can lose their distinctive hue. Carotenoids themselves can bleach in the sun, something the flamingo species Phoenicopterus roseus combats by preening themselves directly with pigments secreted from their glands, giving their feathers a lustrous pink shine.
Flamingos are also one of few birds that feed their young with crop milk. Not to be confused with milk produced from mammalian species, the crop milk produced by flamingos is a highly nutritious bright pink secretion made in an adult’s throat, and is so densely packed with carotenoids that when breeding season is over both male and female parents often appear white, losing the pink colouration from their feathers.
Despite numerous reports of blue flamingos appearing online, there is no evidence to suggest these are anything more than internet hoaxes. However, there have been a number of sightings of a rare black flamingo in Cyprus. It is thought that it suffers from a pigment condition called “melanism”, causing an overproduction of melanin making it black.
