Why Are Flamingos Pink? The Answer Is on Their Plate
Flamingos are not born pink: their color comes from pigments called carotenoids, found in the algae and tiny crustaceans they eat. Without that diet, their feathers fade.
A flamingo is not born pink. Chicks hatch covered in gray down and only gain their famous color over time, as they feed. In other words, flamingos turn pink because of what they eat. The credit goes to a group of natural pigments called carotenoids.
Carotenoids: the pigments behind the pink
Carotenoids are red, orange and yellow pigments made by plants, algae and some microorganisms. They are the same compounds that color carrots and tomatoes. Animals cannot make carotenoids on their own: they have to get them from food. In flamingos, these pigments are processed by the body, with help from the liver, and deposited in the feathers, skin and bill.
What flamingos eat
Flamingos live in shallow lagoons, often salty or alkaline, and feed by filtering water and mud with their bills held upside down. Thin plates in the bill, called lamellae, trap food while the water is pushed out the sides. The menu includes:
- Microscopic algae, rich in carotenoids.
- Tiny crustaceans such as brine shrimp, which also build up carotenoids by eating algae.
- Insect larvae and small mollusks.
- Seeds and other plant matter.
Species also specialize. According to San Diego Zoo, lesser, Andean and James's flamingos have bills better suited to filtering fine particles such as algae, while greater and Chilean flamingos feed mostly on invertebrates from the muddy bottom.
Why some are pinker than others
There are six flamingo species, and the intensity of their color varies a lot. The American, or Caribbean, flamingo is the most vivid, with reds, pinks and oranges. Within a single species, color depends on location and on how many carotenoids are available in the food: some birds are pale pink, almost white, and others deeply colored.
Color also tells a story about a bird's life. Chicks stay gray while their parents feed them crop milk, a nutritious fluid produced in the upper digestive tract of both males and females. Adult coloring takes time: the Smithsonian's National Zoo says several years, and the Los Angeles Zoo says about two. While raising young, the parents themselves can lose color and turn pale pink or almost white, regaining it once the chick feeds on its own.
Natural makeup
There is one more trick. A study by researchers at the Doñana Biological Station in Spain, published in 2010 in the journal Behavioral Ecology and Sociobiology, found that greater flamingos rub their heads on the uropygial (preen) gland near the tail and spread the secretion over the feathers of the neck, breast and back. The secretion contains carotenoids and intensifies the color. The authors noted that plumage is most colorful during courtship displays and fades the rest of the year, and proposed that the behavior helps attract mates.
What about zoos?
Because the color depends on diet, captive flamingos would fade if they ate ordinary feed. That is why zoos give them a special diet with added pigment. The Los Angeles Zoo, for example, says it includes canthaxanthin, a carotenoid, in the birds' food to maintain their color.
In the end, a flamingo's pink works like a walking nutrition label: it shows the bird is eating well and has access to the right pigments. The same rule applies to people on a smaller scale. Eating lots of carrots can turn your skin slightly orange, but carotenoids never paint our whole appearance the way they do for flamingos.
