Flamingos are known for their distinctive pink or reddish color. But why are flamingos pink? What determines the color of a flamingo’s feathers? In this article, we’ll explore the biology, diet, and environment that give flamingos their colorful plumage.
What Causes Flamingos to be Pink?
Flamingos get their pink color from carotenoid pigments in their diet. Carotenoids are natural pigments that are found in the food flamingos eat. The major carotenoids that cause flamingo’s pink coloration are:
Canthaxanthin
Canthaxanthin is a red-orange carotenoid pigment that is commonly found in algae and plants. When flamingos consume food sources containing canthaxanthin, it is deposited into new feather growth and causes a pinkish coloration. Canthaxanthin is thought to make up about 60-70% of flamingos’ total carotenoid pigments.
Astaxanthin
Astaxanthin provides a red pigmentation and makes up about 30% of the carotenoids in a flamingo’s diet. Astaxanthin is found in algae, yeast, salmon, lobster, and other seafood.
Zeaxanthin
Zeaxanthin is a reddish carotenoid that gives flamingos yellow, orange, and red colors. Zeaxanthin is found in high concentrations in foods like corn, saffron, and paprika. However, zeaxanthin makes up only about 3-5% of total carotenoids in flamingos.
Flamingo Diet
The carotenoid pigments that cause flamingos’ pink feathers are obtained primarily from their diet. Flamingos are filter feeders, using their beaks to filter algae, plankton, brine shrimp, and other small organisms out of the water. Here are some key dietary sources of carotenoids for flamingos:
Algae
Algae contain high levels of canthaxanthin and astaxanthin. Flamingos consume large amounts of algal matter in the water by filter feeding. Spirulina, red algae, and cyanobacteria are common sources.
Brine Shrimp
Brine shrimp eat carotenoid-containing algae and plankton. When flamingos eat brine shrimp, they ingest concentrated amounts of carotenoid pigments.
Plankton
Like brine shrimp, plankton consumes algae and becomes concentrated in carotenoids. By eating plankton, flamingos obtain pink pigments.
Crustaceans
Small crustaceans like shrimp and some aquatic insects contain astaxanthin and other carotenoids. Flamingos sometimes supplement their diet with these carotenoid-rich invertebrates.
How Flamingos Process Carotenoids
Once consumed, how do carotenoids from a flamingo’s diet get processed and deposited into feathers? Here’s a closer look:
Digestion and Absorption
Carotenoids are hydrophobic (repelled by water) so they must be first emulsified into droplets in the digestive tract so they can be absorbed. Bile salts and fats help break down carotenoids into micelles that can enter the bloodstream.
Transport
The carotenoid pigments are transported in the bloodstream by lipoproteins to sites of new feather growth. Lipoproteins help solubilize the hydrophobic carotenoids in blood.
Deposition into Feathers
At new feather follicles, keratinocytes absorb the carotenoids from lipoproteins. The carotenoids are incorporated into the proteins of the growing feathers which gives them their pink coloration.
How Diet Impacts Flamingo Color
The availability of carotenoid pigments in a flamingo’s diet directly impacts the intensity of pink in its feathers. Here’s how diet can alter feather color:
More Carotenoids = Deeper Pink
A diet high in foods rich in canthaxanthin, astaxanthin, and other carotenoids will produce brighter and deeper pink colored feathers. The more carotenoids consumed, the more intense the pink.
Fewer Carotenoids = Paler Pink
If food availability is scarce and a flamingo’s diet lacks carotenoids for a period of time, new feather growth will have less pigment and be a paler shade of pink. Over time this can lead to almost white feathers if carotenoid intake remains very low.
Different Carotenoids = Different Hues
The types of carotenoids eaten also impact coloration. Diets high in canthaxanthin lead to deep pink while more astaxanthin produces reddish feathers. Other pigments produce orange, yellow, and red hues.
How Molting Affects Flamingo Color
Molting is the process where flamingos shed old feathers and grow new ones. This natural growth cycle influences flamingo color in a few ways:
Molt Reveals Change in Diet
Since feathers hold onto whatever carotenoid pigments were consumed as they grew, molting reveals any dietary color changes that occurred over the previous growth period. New feather color reflects more recent diet.
Juvenile Plumage is Gray or White
Young flamingos hatch with gray or white down feathers. It takes 2-3 years for juveniles to obtain full pink plumage as they consume more carotenoid-rich foods.
Bleaching Fades Color
Molting flamingos may grow in new pink feathers, but sun exposure gradually bleaches and fades carotenoid pigments resulting in lighter overall color until the next molt.
How Habitat Impacts Flamingo Color
The availability of carotenoid sources in a flamingo’s environment also influences feather coloration:
Food Availability
Habitats with extensive shallow lakes, estuaries, and algae-rich waters provide sustained carotenoid availability. Healthy ecosystems support pinker flamingos.
Water Quality
Clean, unpolluted water promotes more algae and brine shrimp growth to feed flamingos carotenoids. Contaminated habitats lead to paler birds.
Salinity
Waters with higher salinity promote growth of carotenoid-containing algae and crustaceans flamingos feed on. Brackish and saline habitats yield pinker feathers.
Types of Flamingos
There are 6 species of flamingo that vary somewhat in their coloration:
Greater Flamingo
| Species: | Phoenicopterus roseus |
| Color: | Bright pink and red |
| Range: | Africa, S. Europe, S. Asia |
The greater flamingo inhabits mudflats, lagoons, and alkaline lakes across three continents. Their bright pink and reddish feathers come from ample carotenoid availability in their diet.
Caribbean Flamingo
| Species: | Phoenicopterus ruber |
| Color: | Vibrant pink and orange |
| Range: | Caribbean islands, N. South America |
The Caribbean flamingo eats a diet rich in shrimp and red algae, giving them deep pink and orange plumage. They live in coastal lagoons and mangrove swamps.
Chilean Flamingo
| Species: | Phoenicopterus chilensis |
| Color: | Pale pink with yellow |
| Range: | South America |
The Chilean flamingo has lighter pink and yellowish feathers. Their diet may be lower in carotenoids. They inhabit salt lakes in Argentina, Chile, and Peru.
Lesser Flamingo
| Species: | Phoeniconaias minor |
| Color: | Pale pink and white |
| Range: | Sub-Saharan Africa |
Lesser flamingos are the palest pink species due to their low carotenoid diet. They feed primarily on Spirulina algae which provides some pigment but also lends a pale coloration.
Andean Flamingo
| Species: | Phoenicoparrus andinus |
| Color: | Pale pink with yellow |
| Range: | Andes mountains in South America |
Like the Chilean flamingo, this high-altitude species feeds on algae in saline lakes resulting in lighter pink plumage with yellow hues.
American Flamingo
| Species: | Phoenicopterus ruber |
| Color: | Bright crimson red |
| Range: | Caribbean islands, Galapagos islands |
Found in the Galapagos and Caribbean islands, the American flamingo displays the deepest red coloration which likely comes from a diet very rich in the carotenoid astaxanthin.
Why Do Flamingos Stand on One Leg?
Flamingos often balance on one leg while standing. There are a few theories as to why they stand this way:
Energy Conservation
Standing on one leg allows flamingos to conserve body heat and energy. Tucking one leg up reduces circulation to the cold foot and minimizes heat loss.
Comfort
Standing on one leg may simply be more comfortable for flamingos as it reduces strain on joints and muscles.
Resting Half the Body
Flamingos alternate legs when standing to evenly rest their limbs. It gives each leg a break in turn.
Balance
Flamingos’ long spindly legs are designed for wading, not standing. Tucking one up improves balance and stability while standing on shore.
Conclusion
A flamingo’s distinctive coloration comes from carotenoid pigments in the food they eat. Habitat, diet, and molting all impact the intensity of pink in a flamingo’s feathers. Flamingos absorb carotenoids, metabolize them, and deposit them into new feather growths. Different species across the world display variations of pink, orange, red, and yellow based on available food sources in their unique ecosystems. A flamingo’s color can signify health, diet, and habitat quality. The next time you see these brightly colored birds, you’ll understand just what gives them their beautiful pink plumage.
