Flamingo

About the flamingo

Flamingos are wading birds in the family Phoenicopteridae, the only living family in the order Phoenicopteriformes. Six species are recognized today, four found across the Americas and the Caribbean and two native to Afro-Eurasia. The name comes from the Portuguese or Spanish flamengo, meaning "flame-colored," and a group of flamingos is known, fittingly, as a "flamboyance." Despite long being grouped near storks and ibises, genetic and physical evidence points to a different set of relatives entirely: recent studies find flamingos share numerous traits with grebes, unrelated diving waterbirds, enough that researchers have proposed grouping the two into a joint category sometimes called Mirandornithes.

The largest flamingos, the greater and American flamingos, stand 120 to 145 cm (47 to 57 in) tall and weigh 2.1 to 4.1 kg (4.6 to 9.0 lb), with a wingspan reaching 140 to 165 cm (55 to 65 in). The lesser flamingo is the smallest species, standing just 80 to 90 cm (31 to 35 in) and weighing 1.5 to 2 kg (3.3 to 4.4 lb), with a wingspan as small as 95 to 100 cm (37 to 39 in); the James's flamingo is only slightly larger, at 90 to 92 cm (35 to 36 in) tall. Young flamingos hatch with grayish-red down, and it's only as adults that the birds take on their signature pink-to-red coloring, produced by carotenoid pigments absorbed from their food and processed by liver enzymes. A well-fed, healthy flamingo shows more vivid color, which makes it a more attractive mate, while a pale or white bird is typically unhealthy or malnourished — captive flamingos are a notable exception, since even well-fed birds can fade if their diet doesn't include enough carotene.

Flamingos are famous for standing on one leg with the other tucked beneath the body, a habit whose exact purpose isn't fully settled. One theory holds that it helps the birds conserve body heat while wading in cold water; another suggests it simply takes less muscular effort to balance on one leg than two, and cadaver studies have shown the one-legged pose can be held with no muscle activity at all. While walking, a flamingo's legs appear to bend backward; that middle joint is actually the ankle, not the knee.

Behavior and diet

Flamingos are filter feeders, and their curved bills are built for the job, working upside down as the bird sweeps its head through water and mud. Hair-like structures called lamellae line the bill and work with a large, rough tongue to strain out food, while rapid head movements and bill-chattering stir up sediment and small prey, and the birds' stomping creates eddies that trap invertebrates. The diet consists of brine shrimp, cyanobacteria, insect larvae, mollusks, and crustaceans, drawn from both animal and plant plankton. Diet also drives color: American flamingos get more beta-carotene from their food and appear a brighter red, while lesser flamingos take in less and stay a paler pink. Flamingos prefer freshwater to drink but are equipped with salt-removing glands beneath the eyes that let them tolerate saltwater as well.

Flamingos are intensely social, living in colonies that can number in the thousands — a strategy that likely helps them avoid predators, find food more efficiently, and make the best use of limited nesting sites. Ahead of breeding, a colony splits into smaller groups of about 15 to 50 birds that perform synchronized displays: stretching their necks upward, calling while flagging their heads, and flapping their wings together, behavior that helps pair up unmated birds and synchronize nesting across the group. Flamingos form strong pair bonds, though birds in larger colonies sometimes change partners, and both members of a pair build the nest and defend it, sometimes against other pairs trying to take over the site.

After hatching, both parents feed chicks a nutrient-rich "crop milk" produced in glands along the digestive tract, containing fat and protein but no carbohydrates. Chicks stay near the nest for about the first six days, then begin exploring; by two weeks old they gather with other chicks into groups called "microcrèches," which merge over time into much larger crèches holding thousands of young birds, while the parents range off to feed. Chicks that stray from these groups become more vulnerable to predators. Flight feathers finish growing in at around three to three and a half months old, at which point the young birds can fly.

Range and habitat

Flamingos occupy a wide swath of the globe: four species live across the Americas, including the Caribbean, and two are native to Afro-Eurasia. As wading birds, they spend much of their time in shallow water, and their tolerance for salt — thanks to specialized glands that filter it from their blood — allows them to make use of saline and alkaline waters that many other birds cannot. Nesting takes place on mudflats, where a pair typically selects the spot together, with the female usually choosing the exact location before building begins.

Conservation status

Flamingos have no single conservation status, because the IUCN Red List assesses each of the six species separately. The American flamingo is listed as Least Concern, while the Chilean flamingo and the lesser flamingo are Near Threatened.

Flamingos also have a long record in captivity. The first flamingo hatched in a European zoo was a Chilean flamingo in Switzerland in 1958, and the same collection has since raised more than 389 birds for zoos around the world. Keepers have used mirrors to make a small group feel like a larger flock, which appears to encourage breeding, and a greater flamingo believed to be at least 83 years old, thought to be the oldest in the world, died in Australia in 2014.