Flamingos use their L-shaped beak and morphing feet to induce vortical traps for prey capture

• 成果类型: Article
• 署名作者: Jimenez, Victor M. Ortega -; Yee, Tien; Rohilla, Pankaj; Seleb, Benjamin; Belair, Jake; Bhamla, Saad
• 署名单位: University of California System; University of California Berkeley; University of Maine System; University of Maine Orono; University System of Georgia; Georgia Institute of Technology; University System of Georgia; Kennesaw State University; University System of Georgia; Georgia Institute of Technology
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8731
• DOI: 10.1073/pnas.2503495122
• 发表日期: 2025-05-12
• 关键词: wilsons phalaropes; chilean flamingo; morphology

摘要

Flamingos feature one of the most sophisticated filter-feeding systems among birds, characterized by upside-down feeding, comb-like lamellae, and a piston-like tongue. However, the hydrodynamic functions of their L-shaped chattering beak, S-curved neck, and distinct behaviors such as stomping and feeding against the flow remain a mystery. Combining live flamingo experiments with live brine shrimp and passive particles, bioinspired physical models, and 3D CFD simulations, we show that flamingos generate self-induced vortical traps using their heads, beaks, and feet to capture agile planktonic prey in harsh fluid environments. When retracting their heads rapidly (similar to 40 cm/s), flamingos generate tornado-like vortices that stir up and upwell bottom sediments and live shrimp aided by their L-shaped beak. Remarkably, they also induce directional flows (similar to 7 cm/s) through asymmetric beak chattering underwater (similar to 12 Hz). Their morphing feet create horizontal eddies during stomping, lifting, and concentrating sediments and brine shrimp, while trapping fast-swimming invertebrates, as confirmed by using a 3D-printed morphing foot model. During interfacial skimming, flamingos produce a vortical recirculation zone at the beak's tip, aiding in prey capture. Experiments using a flamingo-inspired particle collection system indicate that beak chattering improves capture rates by similar to 7x. These findings offer design principles for bioinspired particle collection systems that may be applied to remove pollutants and harmful microorganisms from water bodies.