Only a few of the Galapagos Islands provide the habitat required and preferred by flamingos. On our Galapagos cruise we visit some of these islands where the brackish-water lagoons provide flamingos with ideal habitat. Present in the islands is the American flamingo, Phenicopterus ruber. This species isclosely related to the Greater Flamingo and is still referred to frequently as the “Caribbean flamingo”, although its presence in Galapagos makes that name problematic. It is one of five species of extant Phoenicopteridae, an avian group probably most closely related to Ciconiiformes (storks and herons). Flamingos are generally found in subtropical and tropical estuarine and briny bodies of water across Latin America, Africa, and India, in addition to numerous front lawns, with higher concentrations of these found in Florida than anywhere else in the world.
A highly social species of bird, flamingos in Galapagos are possibly an exception to the rule as they breed successfully in smaller numbers than anywhere else, possibly an adaptation to their overall smaller population and restricted distribution. In other places around the world flamingos are known to gather in groups of over a million individuals. Courtship behavior takes place in groups, with displays and parading usually requiring the participation of many individuals rather than just one pair. Observations of flamingo flocks has shown that relationships between and among individuals can come in many forms: known trios, male couples, female couples and “friendship groups” (mate swapping); an indication that flamingos are not necessarily monogamous (in captivity).
Flamingos are easily distinguishable by their rosy or pink feathers, and the name “flamingo” has its origin in the Latin for “flame”. The American flamingo in Galapagos is considered to be the most brightly colored flamingo in the world. Their diet is primarily brine shrimp, Artemia,which in the lagoons of Galapagos pick up their carotenoids by feeding on unicellular algae and protozoa. One of the most outstanding characteristics of the flamingo is the beak. Inside is a large, fatty, highly sensitive tongue with numerous fleshy spines, which is complemented by a keeled, lamellate bill bent downward from the skull at an angle (“ventroflexed”). When feeding, a flamingo lowers its head until the bill is pointing to the rear with the upper mandible in the water. Then the head is moved from side to side as the animal moves forward. At this time, the lower mandible (which is uppermost at this time) and powerful tongue move as a pump that quickly (5-20 beats/minute) sucks in particulate/Artemia-laden water and expels unwanted items (S.J. Gould made a note in his paper on flamingos that during the Roman era, flamingo tongues were considered a delicacy).
The importance of social behavior among flamingos is also demonstrated in their nesting habits. Flamingos nest in a colonial manner in relative close proximity to one another, possibly an adaptation to improve survival at this particularly vulnerable and dangerous time of life. They are easily influenced by neighboring behaviors, in that if one abandons a nest, they will all abandon their nests.
Nesting usually takes place where both the male and female can draw mud up around their feet until a small “volcano” is made that stands 12 inches off the ground. This can take several weeks to get “just right”, and is an adaptation to a habitat where water levels can frequently change overnight with a good rain or extreme high tide. A single egg is laid and incubated for about one month. Both males and females will take turns incubating while the other forages almost continuously throughout the day and often into the evening. For the first ten days of its life, the chick receives “crop-milk” from both the male and female, and occasionally from a foster feeder as well. This white liquid is formed from the lining of the throat and upper digestive tract which sloughs off with a “creamy” texture – a highly nutritious “Artemia milkshake”!
When the chick leaves the nest, its beak and legs have changed from pink to black, though the bill remains straight for another few weeks. Young flamingos join “creches”-groups of young chicks and slowly learn the difficult task of how to filter-feed. By three months of age their bills will have taken on the adult bend, allowing them to filter their own food although they still depend on their parents to supplement their diet. They remain grey until about one year of age when they start molting into their adult plumage and slowly take on a pink hue from the carotene-rich diet they are now finding for themselves.
A Galapagos census in 2008 by Jimenez-Uzcategui reported 294 adults. This number is at the lower end of a variable population count that over the last few years has been as high as 500 individuals. Flamingos are excellent long-distant fliers, and travel between the islands and lagoons of Galapagos with little effort. The principal breeding lagoons for the flamingo in Galapagos are found in southern Isabela Island, with many smaller lagoons used periodically throughout the archipelago for breeding and/or feeding.