The sister relationship between grebes and flamingos has been established by anatomical and genetic studies.

Flamingos are highly gregarious birds; flocks numbering in the hundreds may be seen in long, curving flight formations and in wading groups along the shore. On some of East Africa 's large lakes, more than a million lesser flamingos gather during the breeding season.

To feed, flamingos tramp the shallows, head down and bill underwater, stirring up organic matter with their webbed feet. They eat various types of food, including diatoms, algae, blue-green algae, and invertebrates such as minute mollusks and crustaceans. While the head swings from side to side, food is strained from the muddy water with small comblike structures inside the bill. The bird's pink colour comes from its food, which contains carotenoid  pigments. The diet of flamingos kept in zoos is sometimes supplemented with food colouring to keep their plumage from fading.

The nest is a truncated cone of muddy clay piled up a few inches in a shallow lagoon; both parents share the month-long incubation of the one or two chalky-white eggs that are laid in the hollow of the cone. Downy white young leave the nest in two or three days and are fed by regurgitation of partly digested food by the adults. Subadults are whitish, acquiring the pink plumage with age.

flamingo. (2011).  Encyclopædia Britannica Ultimate Reference Suite.  Chicago: Encyclopædia Britannica

http://en.wikipedia.org/wiki/Flamingo

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