Flamingos are found on all continents except Antarctica and Australia. Depending on the authority involved, there are up to six distinct species, each with its own range and geographic dispersion.
Specifically, the range of greater flamingos extends across the entire shoreline of Africa, the Mediterranean Sea, parts of Asia and India as well as southern United States, the Caribbean, and Yucatan Peninsula where there are warm coastal habitats.
Flamingos live in large colonies, oftentimes numbering into the thousands of individuals. They tend to occupy large mud flats where the loose mud can be easily formed into the mounds that they use as nests. These large mud flats are usually located near a food supply.
Hyper-saline estuaries are the preferred habitat. They are harsh environments where filter feeders benefit from reduced competition and predation while at the same time being able to take advantage of the abundant food sources. These habitats are often located near larger bodies of water such as coastal areas, sea inlets, rivers, and open lakes. Habitats are nearly always coastal, but they have been known to move inland to lagoons or volcanic lakes.
In colonies of such high density, occasional food shortages arise and flocks will perform short migrations in search of greater food resources. Flamingos show little to no site-tenacity and don't often return to previous flocking sites, or to their birth locations. ("Focus on Flamingos", 2010; "Phoenicopterus ruber", 2008; "Tour du Valat", 2010; Fer, 2006; Gould, 1985; Rooth, 1965; Roynesdal, 2007)
Greater flamingos are one of the larger members of the Aves class with a wingspan measuring 1.5 m wide, standing 1.2 m tall, and weighing 2.1 to 4.1 kg. They are most well-known for their bright pink coloration and in fact, the word "flamingo" derives from old Spanish for "flaming" or "red feather." Individuals have long, graceful necks and legs which in proportion to body size are the longest of any bird. Flamingos will often rest their head on their body in order to avoid fatigue in the neck muscles.
The bill is uniquely adapted for filter-feeding, and its shape is not shared among any other family of birds. Their large bills consist of layers of horny plates used to filter out prey from the water. In contrast to other birds, flamingo's bills are essentially reversed. Flamingo's lower mandibles are larger than the upper, which is not rigidly attached to the skull. Thus when it eats, the upper mandible moves as opposed to the lower, which is completely reversed from all birds and mammals. This reversal is largely attributed to flamingos' method of feeding by submerging their heads upside-down.
Sexual dimorphism is present in that males are slightly larger than females, and females obtain their adult color slightly earlier than males. Otherwise both sexes are uniformly colored. Adults have primarily pink plumage with black flight feathers only visible in flight. They feature pale irises and a pale bill with pink and black on the tip. The legs are bright pink as well and end with pink, webbed feet. Because there is no difference in coloration between the sexes, the bright pink coloration is not likely to be any type of sexual signal, though some researchers suggest it may function equally for both sexes in selecting a mate as a sign of fitness due to overall nutrition status.
Young birds are covered with a downy-type feather when they first hatch. Both their legs and bill are dark gray in color, and only become pink as the bird matures. The feathers are also initially gray, but will gradually be replaced by the pink, adult plumage as the flamingo ages and incorporates carotenoid compounds from its diet into new growth. Maturity generally takes about three years, though some have been seen with juvenile plumage at up to five years of age. ("Focus on Flamingos", 2010; "Greater Flamingo", 2010; "Online etymology dictionary", 2010; "Phoenicopterus ruber Greater Flamingo", 2010; "Tour du Valat", 2010; Fer, 2006; Gould, 1985; Johnson, et al., 1993; King, 2008; Roynesdal, 2007)
Males and females are generally monogamous, remaining together during incubation and nurturing of the young. Mates will often remain together for many years, only choosing a new mate after the death of another.
Mating inis a complex affair. Their highly gregarious nature leads to distinct behaviors for selecting a mate and rearing the young afterward. The entire adult colony prepares for mating. When a colony has found a suitable location, adults will gather near the drinking area. Though birds over one year of age can breed, only fully colored adults will take part in the breeding ritual. The birds will gather and begin displays of their size and coloration. They will elongate their necks, extend their wings, and touch nearby individuals with their beaks and wings. Though it is difficult to determine due to the similar appearance between males and females, it appears that groups of males congregate while displaying. Regardless, the entire flock performs similar displays, oftentimes for months before the breeding itself begins.
This breeding display has various positions which the flamingos adopt, and have been named by researchers. The head is first held extended in the "head flagging," and waved rapidly back and forth while calling loudly. This is followed by a "wing salute," where the dark flight feathers are displayed. The bird will then perform a "twist preen," dipping the head beneath a wing. The wings are again displayed in an "inverted wing salute," followed by stretching a wing and a leg on one side of the body backwards while dipping the head downwards. The entire dance takes only seconds, and is repeated constantly throughout the pre-pairing phase. This usually takes place in shallow water.
A female will usually move farther from the main group when she has found a suitable mate and the male will follow her. Both will continue making various display positions. Females will signal their readiness by keeping their head down near the water level. Males will add a head bobbing display, inverting their neck backward and resting their head on their back. When the female is ready for copulation, she will move to deeper water, and spread her wings to signal the male. ("Focus on Flamingos", 2010; Allen, 1956; Roynesdal, 2007)
There is no set breeding season for flamingos, with young being born at any time of year. However, the colonies as a whole will usually breed concurrently over the warmer seasons following the rains, with most breeding in late spring or early summer. This timing is due more to availability of food supplies than any limitations on seasonal fertility. The main factors which are preliminary to mating appear to be an abundant food supply, suitable mudflats for nesting and creating the creche, and availability of fresh water.
When the mating is complete, both birds will build a nest from the mud. The nest is a small mound approximately twelve inches high, circular, and with a depressed center for the egg to be laid. When available, bits of vegetation, twigs, or feathers are incorporated into the nest. The male will usually begin building, with both partners eventually working on the nest until the egg is laid.
The eggs are large and milky white, about the size of a large orange or grapefruit. A pair of flamingos will usually lay a single egg once per breeding cycle. In the rare cases where two eggs are laid, usually only one will hatch. The egg is incubated by both parents, who take turns as the partner forages away from the nest. Incubation lasts 28 to 32 days, after which the chicks hatch weighing 85 to 102 grams. Hatchlings are semiprecocial with downy feathers and eyes open, but are initially unable to feed themselves. Greater flamingos' specialized beaks do not begin to develop until the young are 2 weeks old. Newly hatched chicks will remain in the nest for the first five to eight days, at which time they gather with other chicks in groups called "creches." Chicks are reared by both parents until ready to fly at 65 to 90 days old. Parents are able to call and locate their young within the creche and continue to provide care until the young fledges. ("Flamingo Infobook", 2009; "Focus on Flamingos", 2010; "Phoenicopterus ruber", 2008; Allen, 1956; Fer, 2006; Rooth, 1965; Roynesdal, 2007)
Both male and female parents provide significant resources for their young. Both participate in building the nest and incubation. A few days before hatching, the chick will begin to produce vocalizations. Imprinting to the parents initially starts through this vocalization while still in the egg. Once newly hatched, a chick recognizes its parents and the parents recognize the chick. Parents provide food for the young hatchling until the chick is ready to forage for itself. This nourishment is called "crop milk," a nutritious secretion from the oral crop of the parents. The milk is similar to human milk, both in composition and because it is stimulated by the same hormone, prolactin. The crop milk of flamingos, however, is red in color due to the pigments present in the diet. This pigment will eventually be incorporated into the chick's feathers, the first step towards the characteristic coloration of flamingos.
All adults can produce this crop milk, but no parent will feed any chick other than its own. If a chick fails to imprint on its parents, no other birds will provide for it and death will result. Consequently, imprinting is of vital importance. The chick is able to recognize its own parents' calls from up to one hundred meters away. When called, only the intended chick will respond, even with other chicks present within hearing range.
When the chick initially leaves the nest, one of the parents will watch over it as it explores its new environment, keeping other birds away until the young are fully integrated into the creche. The chick leaves the nest to join the creche at 5 to 8 days old, yet it still requires parental care until it fledges at 65 to 90 days of age. ("Flamingo Infobook", 2009; "Focus on Flamingos", 2010; "Greater Flamingo", 2010; "Tour du Valat", 2010; Allen, 1956; Kear and Duplaix-Hall, 1975; Rooth, 1965; Roynesdal, 2007)
Chicks generally have a higher mortality rate than adults. At birth, they are unable to fend for themselves and are fully dependent upon their parents. However, if they are able to survive into adulthood, flamingos live an average lifespan of 25 years in the wild with a maximum of 44 years. In captivity, flamingos live an average of 30 years. The oldest flamingo in the world is over 75 years old and resides at the Adelaide Zoo in Australia. ("Flamingo Infobook", 2009; "Focus on Flamingos", 2010; "Greater Flamingo", 2010; King, 2008; Roynesdal, 2007)
Flamingos live, mate, and feed in large flocks, which can consist of thousands of individuals. Flocking is generally a protective mechanism for a species, where an entire group can be alerted to the presence of a predator. In flamingos, this is the case as well, where the birds would individually be at a disadvantage with their heads bent down at the water line while feeding. Flamingos have thus evolved behaviors which lead them to be some of the most social of all birds. They use highly ritualized displays in mating and interacting with other individuals in the colony.
For example, a flamingo must often rest its head on its body to prevent muscle fatigue due to such a long neck. Straightening the neck to its full length can send signals to other members of the flock. It is used in the mating ritual to garner attention, and in threat displays to intimidate other members of the flock. Even when resting its head, an action as seemingly inconsequential as which side of the body to rest on will cause other members of the flock to react differently. Birds which rest their head on the left side will become involved in aggressive altercations with other members more frequently. This may be a method of achieving a social hierarchy within the flock, or a means of sexual competition between members as they strive to achieve dominance.
Large colonies also are beneficial when it comes time to choose a mate. In a closely related species of flamingo, lesser flamingos, large colony size was found to be of importance during breeding. This effect was so pronounced that researchers were able to increase breeding success by placing large mirrors near the nesting sites so that flamingos appeared to be in a larger flock than was truly present. This behavior is thought to extend to greater flamingos as well, as larger colonies have been shown to have more success in breeding.
Flamingos are colonial, yet when foraging for food each individual flamingo becomes fiercely territorial. A bird takes up a "territory" and does not permit others nearby. If another comes too close, the offended bird will engage threatening displays to warn the intruder to leave. This threat display shows the bird's size, as the flamingo will fully extend its neck and open its wings and ruffle its feathers to appear larger. If the warned is not heeded, the two will bite at each others beaks, in what is called "bill fencing." This aggression to other members of the flock is also used when protecting young, and during the mating rituals.
The colony will establish distinct areas where birds can interact freely. The drinking area is one such place. In the hypersaline estuaries where flamingos filter feed, salt intake is quite high and flamingos require a source of fresh water nearby. In contrast to their behavior while feeding, the drinking area is much more permissive. This is also where the breeding rituals begin as members of the flock are in close proximity to one another. Once breeding occurs, an area of the colony becomes designated for nesting, with most members building nests and laying eggs within close proximity of one another.
One of the most distinct aspects of flamingo behavior is their propensity to stand on one leg. A posture is frequently adopted where a bird will stand perched on one of its long legs, the other will be bent at the knee, with the knee held askew from the body and the foot tucked underneath. They seem to show no preference for which leg they stand on, and often will alternate which leg is tucked up. Multiple theories for this odd behavior have been put forth. Some suspected it to be more restful, others thought it somehow provided stability to their stance. Recently, researchers have found that flamingos assume the single leg stance more often when in water and it appears that since a flamingo spends a significant amount of time in water, standing on one foot may provide for greater conservation of body heat. Because only one leg at a time needs be submerged, the other can be tucked underneath the body for warmth. Furthermore, such a posture may also help to reduce parasite load by reducing the amount of the body that is underwater at any one time.
Flamingos will fly with their neck fully extended and their feet held directly behind them. As is common in large birds, flight is achieved from a running start to create lift over their wings. Flamingos have a range of hundreds of miles by air and will travel as a flock in a manner similar to geese, with loud honking and formations in flight. Flamingos can take off from water or from land, and are able to alight on land or water as well. ("Flamingo Infobook", 2009; "Focus on Flamingos", 2010; "Greater Flamingo", 2010; Anderson and Williams, 2009; Fer, 2006; Kear and Duplaix-Hall, 1975; Pickering and Duverge, 1992; Rooth, 1965; Roynesdal, 2007; Walker, 2009)
Though they can fly hundreds of miles if required, their usual range is more limited. They will tend to stay in an area where feeding and nesting is amenable, only leaving if conditions for the flock become intolerable in some manner. Flamingo flocks have moved based on depletion of food sources, arrival of predators, or disturbance from humans. (Allen, 1956; Roynesdal, 2007)
As a social species living in large groups, intraspecific communication can be essential. For instance, parents returning to feed their young after foraging must find their own mate and offspring. In a group with potentially tens of thousands of members, communication serves a vital role in maintaining colony cohesion and interactions among other members.
Flamingos will communicate with other members mainly by vocalizations. While in flight, they will call with loud honking noises, which has been compared to the familiar sound of geese. While on land, the vocalizations are softer in volume. As part of imprinting, chicks begin making vocalizations while still in the egg. Parents learn to recognize their offspring's unique voice before it even hatches, and will recognize their offspring afterward based on such calls.
Adults also rely on physical positions. Visual cues can be used for establishing dominance within the flock. For instance, the choice of which side the head rests on can determine aggressiveness with others. Body language is also communicated by the extent to which feathers are ruffled, similar to the way a cat may raise the hair along its back when threatened - a bird which makes itself appear larger is more threatening to a potential opponent. In such aggressive meetings, birds will also adopt a ritual which involves maneuvering the head and neck in a threatening fashion and producing a clicking sound with the beak by snapping it open and shut quickly. If this warning is ignored, birds may snap their bills at each other in "bill fencing" until one backs down.
Greater flamingos also engage in physical courtship displays, in which males attract females through specific movements and postures. Females will communicate interest by mimicking these movements back to the male.
It is unclear if flamingos utilize any type of chemical or pheromone signaling mechanism. Adult flamingos will often delay mating even after reaching sexual maturity. Whether this unusual behavior is a response to pheromone signaling is not known.
The feeding behaviors of flamingos are one of their most distinctive characteristics. The flamingo's long legs are used to stir up sediment at the bottom of shallow water. The flamingo's bill is equipped with rows of bony projections lining the edges of the interior of their beaks, which function as a sieve. The bird will take a mouthful of water and move its beak to pump water out, using this uniquely curved bill to filter out tiny organisms to eat. Since the flamingo dips its head down into the water to eat, it effectively feeds "upside down," and the beak reflects this in its morphology - both in the spoon-like shape of the bill and the articulation of the joint of the upper jaw. In contrast to mammals and other vertebrates, the upper jaw is able to move during feeding. To picture this evolutionary accomplishment, consider that since flamingos feed with their heads upside down, the bill appears right side up when the head is inverted, an adaptation where a flamingo's upper bill is like another bird's lower bill. The physical top half is the functional bottom half.
Flamingos are not selective in their diet. Anything that can be captured by their filtration feeding method appears to be consumed. Stomachs of wild flamingos have been examined, and flamingos appear to eat organic ooze (bacteria and microscopic organisms), worms, nematodes, molluscs, crustaceans, insects and larvae, and even vertebrates such as small fish. They will also consume vegetable matter. Though they can subsist on a wide variety of foods, small crustaceans are responsible for the bright pink pigment that flamingos are famous for. Carotenoid compounds from the crustaceans is incorporated into the plumage and skin around the legs, and animals become pale which do not receive this nutrient. For instance, individuals kept in zoos that are not fed a supplemented diet will not have the same coloration as wild birds. The sun will cause this coloration to fade over time, so it must be continually supplied to keep the bird's color.
Flamingos' tongues have evolved to be quite muscular in comparison to other birds as they are critical to the pumping mechanism required to pump food through filter system. The tongue was savored as a delicacy in ancient Rome. (Erlich, et al., 1988; Gould, 1985; Rooth, 1965)
Flamingos have very few predators. This is probably largely due to their choice of habitat. Hypersaline estuaries are not favorable for other species, and oftentimes the colonial sites are on islands or other areas only easily accessible by flight. However, various species have been noted to prey on flamingos or their eggs. This short list includes turkey vultures, foxes, badgers, and wild boars. Yellow-legged gulls will prey on eggs and flightless young. Humans will also hunt flamingos for meat or for their eggs. (Allen, 1956; Roynesdal, 2007)
Greater flamingos consume large amounts of aquatic invertebrates, crustaceans, and algae and likely has a large impact on those populations. Flamingos feed in shallow bodies of water, and often use their large feet to stir organisms from the bottom up into the water column. This activity likely contributes to sufficient oxygenation and mixing of organic material within these bodies of water and aids in avoiding anoxic conditions. Greater flamingo eggs and young fall prey to local predators, thus supporting these populations.
Flamingos are also susceptible to pathogens, most notably tuberculosis and avian flu. Large colonies are prime conditions for spread of disease if introduced.
Flamingos are occasionally hunted by local people for food in some areas. Flamingo meat and eggs are sold at markets, but otherwise there is no economic impact towards humans. Their bright pink coloration fades with time, so greater flamingo feathers have not become an animal trade commodity. ("Flamingo Infobook", 2009; "Focus on Flamingos", 2010; "Phoenicopterus ruber Greater Flamingo", 2010; Roynesdal, 2007)
There is no significant negative impact of greater flamingos on humans. Their preference for isolation has kept them largely apart from human areas.
If there is a risk, it is the potential for disease transmission. Large colonies are susceptible to rapid spread of disease and tuberculosis and avian flu, both human respiratory diseases, are common in flamingos. However, since flamingos prefer isolation and will readily flee humans, the risk for transmission is decreased to only when hunted for human consumption. However, this risk remains low and no serious outbreak of human disease has been traced to flamingo populations. (Roynesdal, 2007)
Greater flamingos are currently considered to be non-threatened. Their large range allows them to be more resistant to local changes of habitat that could be more critical for shorter-ranged animals. Greater flamingos readily migrate in response to decreases in habitat quality. Furthermore, the wild population is quite large and both the range and population numbers of greater flamingos appear to be increasing.
Nevertheless, due to the preferred habitat and nesting behaviors of the flamingo, there are areas that conservationists could focus on. Because the colony feeds as a large group, they are susceptible to contaminated food sources. Though this poses no danger for the species as a whole, individual colonies can be affected by local contaminants in their food supply. A flock in Spain, for instance, was afflicted by a toxic strain of cyanobacteria in their food supply, from which many adults in a mature flock perished. Because their feeding locations are often downstream of human activity in less industrialized nations, habitat limitation may be a risk in flamingo conservation.
Likewise, human excursion into the preferred shoreline habitats of these birds may interrupt their nesting and breeding success. For instance, activities as innocuous as photography have been known to disrupt breeding colonies when the birds have considered it a threat and left the region. The isolated nature of their preferred roosts mitigates contact with humans, and at present human activity does not appear to be affecting flamingos to any great extent.
Greater flamingos are also quite easily maintained in captivity, and as popular zoo animals there are large captive populations across the globe. Greater flamingos are thus likely to survive in the rare event that their natural habitat should face an unforeseen calamity. ("Phoenicopterus ruber Greater Flamingo", 2010; "Tour du Valat", 2010; King, 2008; Roynesdal, 2007)
Flamingo specimens in the fossil record have been found that are remarkably similar to modern day species dating as far back as 30 million years ago, with evidence of more primitive forms dating back to the tertiary period. Depending on the authority, there are up to 6 different species of flamingos: greater flamingos (Phoenicopterus roseus), Caribbean flamingos ( ), Chilean flamingos (Phoenicopterus chilensis), lesser flamingos (Phoeniconaias minor), Andean flamingos (Phoenicoparrus andinus), and James's flamingos (Phoenicoparrus jamesi).
However, Caribbean flamingos are often classified as a subspecies of greater flamingos. When this convention is followed, they are referred to as Phoenicopterus ruber ruber and Phoenicopterus ruber roseus respectively. While this issue is not yet settled, there are certain strong morphological characteristics shared between the two, most notably in the bill morphology. For the purposes of this article, the two were considered to be members of the same species. ("Focus on Flamingos", 2010; "Tour du Valat", 2010; Brown, 1959; Kear and Duplaix-Hall, 1975)
Adam Meziani (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, Rachelle Sterling (editor), Special Projects.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the southern part of the New World. In other words, Central and South America.