Flamingos at San Francisco Zoo. In the wild, flamingos eat algae, crustaceans, brine shrimp, diatoms, and aquatic plants. At the zoo, a special “flamingo fare” is served. To preserve their rosy color at the zoo, flamingos are fed a commercially prepared diet high in carotenoids. Initially, zoos fed carrots, red peppers, and dried shrimp to flamingos, but it was found that if synthetic canthaxanthin was added to their feed, nesting and breeding were more successful.

What do zoo flamingos and farmed salmon have in common?

Both salmon farmers and zookeepers rely on doses of a carotenoid, such as canthaxanthin or a similar pigment, to keep fish and flamingos colorful. In both cases, this pigment is responsible for mimicking the color found naturally in wild species. In zoos, flamingos need a diet rich in carotenoids to maintain their distinctive plumage. Carotenoids also occur in mollusks and crustaceans, so flamingos may be fed shrimp and clams. Spoonbills and pink ibis also rely on ingested carotenoids for their coloring.

Lesser, James, and Andean flamingos eat algae, cyanobacteria, and hard-shelled, single-celled plants. They have larger bills and stiff lamellae to filter fine particles from the water. Caribbean, Chilean, and Greater flamingos eat larger organisms, such as insects, invertebrates, and small fish, using their feet to stir up shrimp and larvae from the waterbed.

Why are they pink?

Flamingo feathers obtain their wonderful rosy pink color from pigments in the organisms they eat. The flamingos’ feathers, legs, and face are colored by their diet, which is rich in alpha and beta carotenoid pigments.

Carotenoids in crustaceans such as those in the flamingo diet are frequently linked to protein molecules, and may be blue or green. After being digested, the carotenoid pigments dissolve in fats and are deposited in the growing feathers, becoming orange or pink. The same effect is seen when shrimp change color during cooking. The amount of pigment laid down in the feathers depends on the quantity of pigment in the flamingo’s diet. An absence of carotenoids in its food will result in new feather growth that is very pale; the existing pigment is lost through molting.

A flamingo chick will leave the nest after four to seven days, when it is strong enough to stand and walk. Parents keep a close, protective watch on their chick as it explores its habitat.

Flamingo parents remain close-by as their chicks begin to explore their environment.

Chicks gather in large groups called creches (French for “crib”). Parents are able to locate their own chicks in the creche at feeding time.

Adults feed their chicks a secretion of the upper digestive tract referred to as “milk”. “Milk” secretion is caused by the hormone prolactin, which both the male and female flamingo produce.

•  ”Milk” is 8% to 9% protein and 15% fat, similar to mammal milk.
•  ”Milk” is red in color due to the pigment canthaxanthin. Chicks store this pigment in the liver, to be deposited in their adult feathers when they grow.

CHICK DEVELOPMENT
Flamingo chicks are able to swim before they are typically old enough to leave the nest for good.

Young chicks have been seen imitating feeding methods while standing in shallow water.

Chicks begin to grow their flight feathers after 11 weeks. At the same time, the bill begins to hook, allowing the chick to feed itself.

Chicks lose their juvenile gray or white color gradually over a two or three year period, at which time their pink feathers begin to show.

HUMAN INTERACTION
Habitat destruction by humans has had a negative effect on the breeding and feeding grounds of flamingos.

• Construction of roads and highways make the flamingo’s environment more accessible to people and land predators.
• Coastal desert irrigation has altered water levels in many flamingo habitats.
• Mining of boron, lithium, nitrates, potassium, and molybdenum has caused habitat disturbances for the flamingos.
• Low-flying aircraft bringing tourists, bird enthusiasts, and photographers into flamingo nesting and feeding grounds cause disturbances and affect the birds’ lifestyle.

People have used flamingos and their eggs as food.

• Historically, people have used flamingo eggs as a primary food source and delicacy. Today, in some places, flamingo eggs are removed from nests and sold at markets.
• In early Roman times, flamingo tongues were carefully prepared, pickled, and served as a delicacy.
• Andean miners have killed flamingos for their fat, believed to be a cure for tuberculosis.

Greater and lesser flamingo chicks in the Magadi colony in Africa were banded in the 1960′s with the hope of finding out more about these birds’ lifestyles and migration patterns. Unfortunately, only a few of the banded birds have been recovered. It is believed that the bands may have dissolved because of the high alkaline content in the water where these birds live.

Human activity on Great Inagua Island in the Bahamas has helped flamingo populations. Salt production has added many acres of suitable habitat, stabilized water levels, and provided additional food sources.

Both the male and female take turns incubating the egg by sitting on top of the nest mound.

• During incubation, flamingos will stand, stretch their wings, and preen themselves frequently.
•   A parent bird carefully lifts and turns the egg with its bill.

Eggs that fall from the nesting mound are not retrieved.

HATCHING
Hatching takes between 24 and 36 hours.

Hatching can take between 24 and 36 hours, during which the chick calls frequently and the parents respond anxiously.

The chick calls frequently as it breaks out of the shell.

The chick breaks through the shell using a growth on its bill called an “egg tooth”. The egg tooth is not a true tooth and falls off soon after the chick hatches.

Flamingo parents appear anxious while their chick is hatching. They stand, look at the egg, and vocalize.

The adult stands, looks down, and gently preens and nibbles at the emerging chick.

CHICK AT HATCHING
Newly-hatched chicks have gray or white down feathers, a straight red bill, and plump, swollen red or pink legs.

The leg swelling decreases approximately 48 hours after hatching, and the red bill and legs turn black in seven to ten days.

After hatching, a flamingo chick is not very agile. Movement is limited to pushing its wings or lifting its head.

Flamingos are attentive parents.

Flamingos reach sexual maturity several years after hatching and usually begin to breed at about six years of age.

BREEDING SEASONS

Flamingo colonies may breed at different times of the year. Breeding success is based on synchronous nesting of a flamingo colony so that chicks of a colony hatch around the same time in any one year. Colonies very rarely nest more than once a year.

Breeding and nest building may depend on rainfall and its effect on food supply.

COURTSHIP

Groups of flamingos perform ritualized stretching and preening when courting begins.

Males group together and often run with bills pointed toward the sky and necks held straight out.

Birds interested in one another call to each other frequently and in unison.

PAIR BONDING

Pair bonding is very strong, and flamingos may be monogamous. However, flamingos have been observed to mate with more than one partner.

Pair bonding is very strong among flamingos.

COPULATION

A female will most often initiate copulation by walking away from the group. A male follows close behind.

The female stops, lowers her head, and spreads her wings. This behavior is an invitation to the male to mount her.

Mating occurs in the water. The male jumps onto the female’s back from behind, firmly planting his feet on her wing joints.

After mating, the male stands on the female’s back, then jumps off over her head.

NESTING

Flamingos build nest mounds made of mud, small stones, straw, and feathers. These mounds can be as high as 30 cm (12 in.) Flamingos build nest mounds as high as 30 cm (12 in.) to protect their eggs and chicks from heat and flooding.

Mound building begins up to six weeks before the eggs are laid.

Using their bills, both male and female participate in mound building by bringing mud and other objects toward their feet.

As they slowly construct the mound, the parents make a shallow well on the top, where the female will lay the egg.

Mounds serve as protection against the extreme heat and flooding that occurs at ground level.

Mound building continues during incubation, as the flamingos pick up materials close to the nest.

EGG LAYING

1.  Flamingos most often lay one large egg. Eggs range in size from about 78 by 49 mm (3 x 1.9 in.) and 115 g (4 oz.), to 90 by 55 mm (3.5 x 2.1 in.) and 140 g (4.9 oz.).

2.  The egg is oblong in shape, similar to that of a chicken.

3.  The egg is usually chalky white, but may be pale blue immediately after it is laid.

4.  Females have been known to lay two eggs, but this is rare.

1.  Blue-green and red algae, diatoms, larval and adult forms of small insects, crustaceans, molluscs, and small fishes make up the main diet of flamingos.

2.  A flamingo’s pink or reddish feather, leg, and facial coloration come from a diet high in alpha and beta carotenoid pigments, including canthaxanthin. The richest sources of carotenoids are found in the algae and various invertebrates that make up the bulk of a flamingo’s diet.

3.  The shape of flamingo’s filtering bill determines its diet. A flamingo will either have a shallow or a deep-keeled bill.

• Lesser, James’, and Andean flamingos have deep-keeled bills and feed mainly on algae and diatoms.
• Greater, Caribbean, and Chilean flamingos have shallow-keeled bills and feed on insects, aquatic invertebrates, and small fishes. Caribbean flamingos eat larval and pupal forms of flies and brine shrimp as their main food.

4.  Slight differences in diet and habits prevent competition among flamingos that share feeding grounds.

FOOD INTAKE

1.  Lesser flamingos eat an estimated 60 g (2.1 oz.) dry weight to fulfill their daily food requirements. Through slow-motion photography, researchers discovered that these birds pump water through their bills 20 times a second to filter their food.

2.  A much slower filtration rate was found in the Caribbean flamingos – only 4 to 5 times a second to filter out their daily food requirements of 270 g (9.5 oz.) dry weight.

METHODS OF COLLECTING AND EATING FOODS

1.  Standing in shallow water, flamingos lower their necks and tilt their heads slightly upside-down, allowing their bills to hang upside-down facing backward in the water.

2.  Flamingos sweep their heads from side to side just below the surface of the water to collect their food if they have a deep-keeled mandible. If the mandible is shallow-keeled, a flamingo sweeps its head from side to side deeper into the mud to collect its food.

3.  A flamingo filters its food out of the water and mud with a spiny, piston-like tongue that aids in sucking food-filled water past the lamellae inside the curved bill. The fringed lamellae filter out food, and the water is passed back out of the bill.

4.  In addition to filtering food into the bill, lamellae also exclude foods that may be too large or small for the flamingo.

5.  Standing in water, flamingos may stamp their webbed feet to stir up food from the bottom.

ZOOLOGICAL DIET

Flamingos are fed a varied diet in zoological environments in order to maintain their pink coloration, as well as their general health.

SeaWorld and Busch Gardens feed flamingos a diet that includes all the nutrients needed for optimal health. The flamingos are fed in a specially designed feeding trough.

WATER INTAKE

Flamingos seek out fresh water for drinking.

Flock size ranges from 2 to 340 birds with an average of 71 birds.

SOCIAL BEHAVIOR
Flamingos devote considerable time to collective displays before, during, and after breeding.

Several hundred to several thousand flamingos are all involved simultaneously with ritualized postures and movements to synchronize breeding.

Sometimes only one display is performed, but more often, a predictable sequence of displays are carried out. Not all flamingo species perform all of the described displays, and some perform the displays slightly different than described. Flamingo displays include the following:

•   “Head-flag” involves stretching the neck and head up as high as possible, with the bill pointing upwards, and then rhythmically turning the head from one side to the other.
•  ”Wing-salute” is performed by spreading the wings for a few seconds, showing their striking contrasted colors, while the tail is cocked and neck outstretched.
•  In the “inverted wing-salute”, the flamingo angles its head down, cocks its tail, and orients its body so that the tail is higher than the chest. The wings are then held partially open above the back with the black flight feathers pointing up and the bend in the wing pointing down.
•  ”Twist-preen” entails the bird twisting its neck back and appearing to preen quickly, with its bill behind a partly open wing.
•  ”Wing-leg stretch” involves the leg and wing on the same side stretched out and to the rear.
•  ”Marching” is performed by a large group of flamingos that cluster together, stand erect, and then move in quick, synchronized steps in first one direction and then another.

INDIVIDUAL BEHAVIOR
Flamingos spend most of the day feeding, preening (distributing oil from a gland at the base of their tail to their feathers for waterproofing), resting, and bathing.

Breeding birds feed day or night. Non-breeding birds feed at night and spend the day sleeping or involved in activities such as preening and bathing.

Flamingos spend about 15% to 30% of their time during the day preening. This is a large percentage compared to waterfowl, which preen only about 10% of the time. Flamingos preen with their bills. An oil gland near the base of the tail secretes oil that the flamingo distributes throughout its feathers.

Flamingos swim readily and bathe in shallow fresh water, submerging the whole body.

INTERACTION WITH OTHER SPECIES
Two or more species of flamingos can coexist in the same area at the same time.

There is no evidence that flamingos dive.

Flamingos are often seen in dense packs floating on the surface of the water.

RESPIRATION
Like other birds, flamingos breathe air with lungs. They hold their breath while feeding under water.

SLEEP
When flamingos are resting, they may sit down with their legs tucked beneath them or rest standing on one leg.

Flamingos often rest standing on one leg.

While resting, flamingos face into the wind. This stops wind and rain from penetrating their feathers. When resting on one leg, flamingos can be seen swaying back and forth in the wind.

THERMOREGULATION
Flamingos frequently stand on one leg. Curling a leg under the body keeps the foot warm and conserves body heat. Flamingos stand on one leg in both cool and warm environments.

FLIGHT
To take off, a flamingo runs several steps, begins flapping its wings, and lifts off into the air. When landing the procedure is reversed: the bird touches down and then runs several paces.

A flamingo flies with its head and neck stretched out in front and its legs trailing behind.

Flight speed of a flock of flamingos can reach 50 to 60 kph (31-37 mph).

Flamingos have been known to fly 500 to 600 km (311-373 mi.) each night between habitats.

ADAPTATIONS FOR A HIGH SALINITY ENVIRONMENT
The majority of lakes where flamingos live have extremely high salt concentrations. The only source of fresh water for some of these birds comes from boiling geysers. Flamingos are capable of drinking water at temperatures that approach the boiling point.

Flamingos excrete salt through salt glands in the nostrils.

VOCALIZATIONS
Flamingo vocalizations range from nasal honking to grunting or growling. Flamingos are generally very noisy birds. Variations exist in the voices of different species of flamingos.

Vocalizations play an important role in keeping flocks together as well as in ritualized displays. Specific calls are used in conjunction with certain behaviors.

Vocalizations are used in parent-chick recognition.

VISUAL DISPLAYS
Flamingos communicate with a broad range of visual displays.

EYESIGHT
1. Vision plays an important role in helping flamingos synchronize collective displays of several hundred to several thousand birds.

2. Some biologists believe that a flamingo’s night vision is poor, but better than a human’s.

3. Like most birds, flamingos have well-developed color perception.

4. In zoological settings, flamingos recognize their uniformed keepers among visitors.

TACTILE
Tactile organs on the tongue can be used to ensure that only food is ingested.

TASTE
The sense of taste is poorly developed in birds.

SMELL
Flamingos have little or no sense of smell.

2. There are 12 principal flight feathers located on each wing. These black feathers are visible when the wings are extended.

3. Flamingos have 12 to 16 tail feathers.

4. Contour feathers cover all of the body except the bill and scaled parts of the legs and feet. They protect the skin from damage and help streamline the flamingo for flight.

5. Flamingos molt (shed and replace) their wing and body feathers at irregular intervals ranging from twice a year to once every two years. The molt is related to the breeding cycle.

6. Molted feathers lose their color.