An unlikely high-altitude haven
The Salar de Atacama is the largest salt flat in Chile, covering 3,000 square kilometers. It sits at an average elevation of 2,300 meters, surrounded by the Andes mountains. This environment is the driest non-polar desert in the world, a result of a double rain shadow from both the Andes and the Chilean Coast Range. Despite the hyper-arid conditions, shallow, extremely saline lagoons dot the landscape, such as Laguna Chaxa. These lagoons show a vast underground brine aquifer and can have salt concentrations far exceeding that of the ocean. This seemingly inhospitable world of jagged salt crystals and mineral-rich water is home to specialized life.
Three species and their specialized diet
The lagoons of Salar de Atacama support three of the world's six flamingo species: the Chilean flamingo (Phoenicopterus chilensis), the Andean flamingo (Phoenicoparrus andinus), and James's flamingo (Phoenicoparrus jamesi). The area is one of the few places where all three can be found living and nesting together. The Andean flamingo is the rarest flamingo species in the world and is classified as vulnerable, with an estimated population of about 39,000 individuals.
Their survival here depends on a simple food chain based on extremophiles. The flamingos are filter-feeders, using their specialized beaks to consume microscopic life from the saline water. Their primary food is the brine shrimp Artemia franciscana, a crustacean that thrives in water with salinity up to 25%—nearly ten times saltier than the ocean. They also consume diatoms and other microalgae. The bright pink and red hues of the flamingos' feathers come directly from the beta-carotene and canthaxanthin pigments in the shrimp and algae they eat. Without this specific diet, the birds' plumage would be white or grey.
An important survival behavior is their daily commute. The saline lagoons are too salty to drink, so the flamingos must fly, sometimes for many kilometers, to freshwater sources like springs and rivers at the edge of the salt flat to hydrate. This daily travel allows them to exploit the rich food source of the salt lagoons while meeting their need for fresh water. Andean flamingos are capable of traveling up to 700 miles in a single day.