The Andean flamingo is the rarest flamingo in the world and one of the three flamingo species that inhabit the high Andes in South America. The other two species are Chilean and James's flamingo. The Andean flamingo has the typical elegant body shape, with a long curved neck and long legs. Its body is pale pink, and it has bright upperparts and a distinctive large black wedge or triangle at the rear of the body. Its legs are yellow and its large, curved bill is black and yellow. Young birds are gray until they develop the adult pink plumage.
Andean flamingos are native to the Andean Mountains in South America, including north-central Chile, southern Peru, northwestern Argentina, and western Bolivia. They live in highland salt lakes with relatively sparse vegetation. During winter the flamingos migrate to the lower wetlands in search of food.
Andean flamingos are very gregarious, forming huge flocks numbering tens of thousands. The only usual form of aggression may be between males when they are guarding their mates. These flamingos move between lagoons and ponds throughout the year, searching for food, usually at night and in a flock. They tend to move to lower elevations during winter and may fly up to 700 miles in one day. In the daytime they typically feed in small groups or pairs several meters apart, scattered over the area. They communicate in many different ways with each other, including the wing salute, when they spread their wings out for a few seconds, showing off their colors. They also stretch their necks and flip up their tails. They use a honking noise, similar to that of geese in flight, to keep the group together. They also grunt and growl during mating and when they are being aggressive.
These flamingos are filter feeders, eating mainly diatoms and algae. They feed by stirring the water with their feet, burying their entire head and beak upside down in the water, and sucking up both water and mud. Then, moving their heads from side to side, they extract plankton, insect larvae, and small fish from the water and mud.
Andean flamingos are monogamous and pairs may stay together for several years. These birds breed in colonies numbering thousands of individuals, in December and January. A pair produces one chalky white egg, laid on a mound of mud in shallow water. Both the male and the female incubate the egg, for 27-31 days, and both care for the young. When they hatch, the chicks are fed "crop milk", a substance that comes from the upper digestive tract of the parent birds. The chicks stay in their nest for the following 5 to 8 days and then form groups of chicks called crèches, which can have hundreds of chicks, looked after by just several adult flamingos. Chicks are not able to fend for themselves until aged 6 to 10 months. They will gain sexual maturity and their full adult plumage at 3-6 years of age.
The Andean flamingo is suffering from population decline as a result of habitat loss, changes in water levels due to mining activities, intense egg-collecting, disturbances by humans, and erosion at nest sites.
According to the IUCN Red List, the total number of Andean flamingos is approximately 39,000 individuals. Today this species’ population is stable but it is classified as vulnerable (VU).
Andean flamingos affect populations of aquatic algae, plankton, and diatoms, by eating them as prey items.