They look for food in salt and muddy water, filter out their microscopically small prey and in the meantime also hang their heads upside down. The eating behavior of flamingos enforces respect. And American biologists Write now in Pnas That the way in which the birds proceed is even more ingenious than expected. With their crochet beak and twisting neck, they manage to generate tornado-like swirls, making it easier to flow in.
If you look at the beak of a flamingo, you will first of all have an eye for the outside: the strong curvature, the light pink top, the sharp black point. But the tool is also worthwhile on the inside: along the beak edges are fine, comb-like slats and the tongue is out of proportion. With that, water is sucked in and pressed out along the slats, so that small shrimp and roeipoot lobsters stay behind.
Yet there is more behind the hydrodynamics of the flamingod diet. With the help of experiments with living Chilean flamingos, 3D-printed beaks and legs and computer models, the biologists traced that the flamingos create mini meal flows in the water. They stamp with the legs and head and neck in such a way that an underwater tornado is created, with miniscule particles swirl towards the water surface – just the other way around than with a downward vortex. Every prey that ends up in it is deadly written down, because once at the top of the water column it flows into the flamingomaag.
Swallow
A special role is reserved for the shape of the beak. ‘L-shaped’, the researchers write, although there is no real 90-degree corner. But by opening and closing that crochet beak (while hanging cup-under under pace) and moving up at the same time, they can make the water swallow extra efficiently.
Young flamingos do not yet have L-shaped beaks. As a result, they would be less good at gathering food independently, according to the authors, but that does not have to be a problem because they are still giving ‘crop milk’: a milky substance made of food that first eats the parent animals and then excrete again through the throat. Also extinct Oerflamingos (such as the living between 28 and 13 million years ago Harrisonavis Croizeti) had right beaks than contemporary species. Probably those early birds had a less specialized diet, and there were also larger prey on the menu at the time.
The discovery is not only interesting for bird lovers, the researchers write. In their opinion, the eating behavior of the Flamingo could also serve for inspiration in water treatment plants. With their swirls, mechanical beaks and legs could help bring dirt or harmful organisms to the surface and then remove it.