Flamingos are renowned for their unique feeding behavior and adaptations, including their upside-down head posture and characteristic curved beak. Traditionally, they have been portrayed as passive filter feeders that rely on their piston like tongues and filtering lamellae along their beak to extract microscopic food and mobile planktonic crustaceans from murky, alkaline waters. However, the active predatory strategies of flamingos underwater remain unclear. In this paper we demonstrated —using a combination of live experiments, 3D-printed physical models, and computational fluid dynamics (CFD)— that flamingos use four hydrodynamic mechanisms to facilitate the capture of tiny aquatic prey.
- First, they perform rapid head retractions from the water, generating tornado-like vortices that lift and concentrate prey toward the surface.
- Second, these birds use asymmetric chattering with their beaks to generate a directional flow that drags prey toward their beaks.
- Third, flamingos use their long legs and webbed feet to perform a “stomping dance”, while placing their upside-down heads in front of the feet. This action produces horizontal vortices at each step that entrap and facilitate prey capture.
- Finally, during skimming, they once again exploit the recirculating vortices generated by their upstream-moving head at the water’s surface, which concentrate food particles at the tip of their beak.
Our study reveals that flamingos are specialized predators that actively generate vortex traps and directed flows to capture agile aquatic prey, such as brine shrimps. These results may inspire the design of bioengineered filtration system capable of removing microplastics or biological hazards from water.
In The News
The New York times published an article about our research on flamingo hydrodynamics. News from UC Berkeley, National Geographic, Scientific American, BBC Wildlife, Science News, and others also posted a note. NPR’s Short Wave podcast aired an episode titled “Flamingos are efficient predators thanks to water vortexes“. Paper was recently published in PNAS.