The flamingo is well-known for its habit of eating with its head upside-down. This behavior is largely due to the structure of its mouth and the logistics of lowering its long, graceful neck into the water. This behavior allows flamingos to feed effectively in their natural habitat, but it has ramifications in other aspects of their lives.
Authorities differ on the classification of flamingos; at least six species or subspecies are recognized by some authorities. The most well-known forms are the greater flamingo (Phoenicopterus roseus ) and the Caribbean flamingo (Phoenicopterus ruber ). Some scientists consider these two forms to be subspecies of the same species, designating them Phoenicopterus roseus rosues and Phoenicopterus roseus ruber, respectively. Fossil flamingos from 30 million years ago resemble modern flamingos in most respects, illustrating the success of the lineage.
Natural History of Flamingos
Flamingos are found on all continents except Antarctica and Australia. Flamingos are very gregarious animals that live in huge colonies, sometimes numbering into the thousands; one colony studied in 1992 by J. del Hoyo, et al., contained more than 200,000 breeding pairs. They are always found near water and do most of their foraging in hypersaline water bodies. Flamingos also require a fresh water source as the hypersaline water is too salty for drinking. These fresh water sources often serve as the nexus for breeding activity. Flamingos are generally monogamous and will often keep the same mate for life. Flamingos migrate when food runs low or some disturbance takes place such as the appearance of a predator. Flamingos have few natural predators as adults, thanks to their colonial nature and reliance on habitats that are hard to reach and often surrounded by water.
Feeding Behavior and Adaptations
Flamingos are filter feeders. They walk in the shallow, salty water and stir up the bottom with their long legs. The flamingo then leans its long neck down to the water and scoops up a mouthful of water, then closes its mouth and uses its tongue to force the water through comb-like extensions on the beak that allow the water to escape while retaining food to be swallowed. Flamingos are not picky eaters -- through stomach content analysis, scientists have documented dozens of flamingo foods, including crustaceans, worms, algae, insects, organic debris, plant material and fish. The crustaceans and algae contain carotenoids that produce the birds’ pink coloration. Because the flamingo must use its beak in an upside-down manner, the beak has evolved to reflect this. The flamingo’s top beak functions like the bottom beak of most birds, and vice versa. Flamingos are among the very few animals that are able to move their top jaw while eating.
Ramifications of the Feeding Behavior
As flamingos are extremely vulnerable when feeding, their colonial nature may have evolved to protect them; when a non-feeding flamingo spots a predator, it alerts the feeding -- and unaware -- flamingos of the danger. Unfortunately, the practice of forming these large colonies means the birds face a few specific dangers. Large groups of flamingos spread disease among themselves rapidly, and this makes them susceptible to pathogens like avian flu and tuberculosis. Additionally, if their food source somehow becomes polluted or toxic and they don’t move to another source, the entire colony is at risk.