The greater flamingo is the tallest flamingo, standing 120 to 150 cm (47-59 in.) and weighing up to 3.5 kg (7.7 lbs.).
The lesser flamingo is the smallest flamingo, standing 80 cm (31.5 in.) and weighing only 2.5 kg (5.5 lbs.).
Males reach full size between one-and-a-half and two years.
Male flamingos are slightly larger than females, weighing more and having longer wingspans; however, visual sex determination of flamingos is unreliable.
The wingspan of flamingos ranges from 95 to 100 cm (37-39 in.) for the lesser flamingo to 140 to 165 cm (55-65 in.) for the greater flamingo. The Caribbean flamingo has a wingspan of 150 cm (59 in.).
Feather color varies with species, ranging from pale pink to crimson or vermilion.
- Caribbean flamingos have the brightest coloration: crimson or vermilion.
- The Chilean flamingo is pale pink.
Feather coloration is derived from carotenoid pigments found in a flamingo's food.
Male and female flamingo coloration is the same.
Newly-hatched chicks are gray or white.
Juveniles are grayish, taking approximately one to two years to obtain full adult coloration.
Parents may lose some of their pink coloration while raising young.
Coloration of a flamingo's legs and feet varies according to species - from yellow to orange or pink-red. The Andean flamingo is the only species that has yellow legs and feet.
- The legs of adult flamingos are longer than the flamingo's body, measuring between 80 to 125 cm (31.5-49 in.), depending on the species.
- The ankle is located about halfway up the leg.
- The knee is located close to the body and is not externally visible.
- The Chilean, greater, and lesser flamingos have three forward-pointing toes and a hallux, or hind toe.
- Andean and James' flamingos have three toes and no hallux.
- Webbing between the toes aids the bird in swimming and stirring up food.
- Coloration of the feet and legs is the same.
- The wingspan of flamingos ranges from 95 to 100 cm (37-39 in.) on the lesser flamingo to 140 to 165 cm (55-65 in.) on the greater flamingo. The Caribbean flamingo has a wingspan of 150 cm (59 in.).
- There are 12 principal flight feathers located on each wing. These black feathers are visible when the wings are extended.
- The neck is long and sinuous. A flamingo has 19 elongated cervical (neck) vertebrae allowing for maximum movement and twisting.
- The eyes are located on either side of the head.
- Flamingo chicks have gray eyes for approximately the first year of life. Adult flamingos have yellow eyes.
- An adult flamingo's bill is black, pinkish, or cream-colored. Coloration varies according to species.
- The bill is adapted for filter feeding. The upper and lower bill, or mandible, is angled downward just below the nostril.
- The upper mandible is thin and flat, and functions like a lid to the lower mandible. The lower mandible is large and trough- or keel-shaped.
- Tooth-like ridges on the outside of a flamingo's bill help filter food from the water.
- Both the upper and lower mandibles contain two rows of a bristled, comb-like or hair-like structure called lamellae. When the mandibles come together, the lamellae of the upper and lower mandibles mesh.
- The number of lamellae in a flamingo's bill varies according to species. The Andean flamingo has about 9 lamellae per cm (23 per in.). The James' flamingo has about 21 lamellae per cm (53 per in.). The Chilean flamingo has about 5 to 6 lamellae per cm (13-15 per in.).
- James' and Andean flamingos have a deep, narrow trough-like lower mandible, which allows them to eat small foods such as algae and diatoms.
- The lower mandible of Caribbean, greater, and Chilean flamingos is wide, allowing them to feed on larger foods such as brineflies, shrimp, and molluscs.
- A flamingo's large, fleshy tongue is covered with bristle-like projections that help filter water and food particles through the lamellae.
Adult feathers have a small, delicate, accessory feather arising from the main feather at the point where the quill merges into the shaft of the feather. This is called an aftershaft.
There are 12 principal flight feathers located on each wing. These black feathers are visible when the wings are extended.
Flamingos have 12 to 16 tail feathers.
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.
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.
Molted feathers lose their color.