The Role of Diet in Flamingo Coloration: Why They Are Pink

Flamingos (Phoenicopteriformes) are recognized for their long and slender legs and their brilliant pink plumage. They do not resemble any other birds. The six remaining species of flamingos are the only extant members of their family, Phoenicopteriformes, and have been around for over 33 million years. How does a species survive for such a long time? What do these exotic birds eat? Flamingos wouldn’t be who they are without their diets, and they wouldn’t be able to feed as they do without their unique physiological adaptations. Continue reading to discover what and how flamingos eat.

What Flamingos Eat

Flamingos are omnivores that won’t pass up the opportunity for either meat or vegetation, though their diet varies depending on the species. There are six different flamingo species, and their diets are affected by the availability of food and the design of their bills. Flamingos with deep-keeled bills include the James’s, Andean, and lesser flamingos. Species with shallow-keeled bills include the Chilean, great, and Caribbean flamingos.

Out of necessity, deep-keeled flamingo species are more herbivorous than their shallow-keeled brethren. Plankton and algae make up the bulk of their diets. They feed on blue-green algae known as cyanobacteria, which possess a high nutritional content and are especially high in beta carotene. By contrast, shallow-keeled flamingo species tend to have a more carnivorous diet that includes small invertebrates, insect larvae, small fish, and brine shrimp. The dietary habits of flamingos are very similar whether it’s an Old World or New World species, but they are distinct enough that multiple species can often occupy the same habitat without having to compete for dinner.

Foods that make up the typical flamingo’s diet include:

• Blue-green algae (cyanobacteria)
• Red algae
• Invertebrates
• Small fish
• Insects
• Insect larva
• Brine shrimp

What Flamingo Chicks Eat

Flamingo chicks are fed a substance known as crop milk, which their parents produce in the back of their throats and then regurgitate to their young. The diet is high in protein and fat, designed to facilitate the rapid growth of the chicks. They’ll continue to feed like this until they reach 7 to 13 weeks of age, at which time they transition to an adult diet. At this point, the flamingo will begin to develop its trademark pink hue — a side effect of the beta carotene that’s abundant in both blue algae and brine shrimp.

How Flamingos Forage

Flamingos are filter feeders like baleen whales, meaning that they stick their bills in shallow bodies of water and then push out the water and mud while holding the nutritious matter inside their bills. The flamingo’s quick and powerful tongue pushes away any food that’s too large to ingest. What remains is then carried past a series of comb-like structures called lamellae, which filter out water while retaining the food. This filtering process happens incredibly quickly, but the speed can vary depending on the species of flamingo. Lesser flamingos can pump water from their bills 20 times per second, while Caribbean flamingos accomplish the same task about four or six times per second.

The shape of the bill affects both what a flamingo eats and how they filter their food. Flamingos with deep-keeled mandibles will glide their bills gently across the water’s surface, while those with shallow-keeled mandibles will instead plunge their bills into the deeper mud to stir up potential prey. They may also stomp their feet in the mud to achieve the same effect. The typical flamingo spends hours each day going through this filtering process, but requires a surprisingly small amount of food. Lesser flamingos only need about two dry ounces of food per day. Although they feed in salty waters, flamingos drink only freshwater. Despite their low food intake, the typical flamingo swallows gallons of freshwater each day.

Animals That Eat Flamingos

Flamingos might seem like easy prey thanks to their bright pink plumage, but the habitats they choose to feed in serve as one of the biggest impediments to predators. Since their feeding grounds are in the water, they’re inaccessible to many of the natural predators in their ecosystem throughout much of the year. In some instances, flamingos have even adapted to survive in environments far too harsh for the average predator. Tanzania’s Lake Natron and Kenya’s Lake Bogoria are toxic due to their harsh salinity levels. It’s only thanks to their long, scaly legs that flamingos can survive in these waters, but this adaptation does an effective job of keeping most predators away.

When the water levels start to drop, however, flamingos become more vulnerable to land predators. Big cats like lions and leopards have attacked African flamingo species, and while hyenas are a regular nuisance, they’re rarely a deadly threat. New World species can face threats from Geoffroy’s cat (Leopardus geoffroyi), foxes, and jaguars. Flamingos have even been prey for pythons and wild boars.

Are Flamingos Pink Because They Eat Shrimp?

Flamingos are pink because of a specific type of plankton in their diet. The algae that flamingos feed on are rich in beta carotene, and that’s the chemical that causes their plumage to develop its pink hue. Shrimp absorb this chemical when eating the plankton and then transfer the chemicals to the flamingo when it devours them, but flamingos can also get their color from feeding directly on the algae or fly larvae.