Flamingos are one of a handful of birds adapted to filter feeding, but their feeding style is unique.
They put their heads "upside down", scoop water with their "upper" bill and force water out through hair-like structures called 'lamellae'.
(📷: John Cancalosi)
Stephen Jay Gould termed this inverted bill structure "The Flamingo's Smile" and challenges readers to think about the natural history that led to this inversion of structure-function.
They have a hinged UPPER beak structure, an inversion of the more common rigid upper/hinged lower beak of Neoaves.
The muscular tongue provides the pumping motion that removes water, retains blue-green algae and tiny crustaceans that give the flamingo its distinctive pink coloration (and me: nightmares)
It also made flamingo tongue a delicacy in Ancient Rome.
(📷: Geoffrey Einon)
What we're seeing in the flamingo is the end of a long process of slow adaptation, modifying existing structures, to make a filter feeder 'par excellence'.
The muscles and jaw structures have been selected from existing genetic variation to produce something unique in the natural world.
There are other fun flamingo adaptations:
1. They have an organ that excretes salt, so they can drink saltwater.
2. Adults secrete 'crop milk' to feed young. Because of the carotenoids in their diet, this red liquid looks like blood.
3. Same-sex couples raising chicks are common in large flocks.
