A team of mathematicians has conducted a study that sheds light on the aerodynamic interactions that allow birds to fly in coordinated formations. This research has implications for understanding how animals, such as fish that move in schools, take advantage of flow dynamics to save energy and reduce drag. The findings could also have applications in transportation and energy, such as more efficient propulsion through air or water and harnessing power from wind, water currents, or waves. The study, published in Nature Communications, reveals that aerodynamic interactions benefit small bird flocks but disrupt larger groups, causing collisions and dislodging members from their positions.
The team’s research involved creating mechanized flappers that mimic bird wings to replicate how air flows around the wings during flight. By studying how these “mock flocks” interact in water, the researchers were able to observe how the flows affected the organization of different-sized groups. For smaller groups of up to four flyers, aerodynamic interactions helped maintain orderly spacing by pushing displaced members back into place using vortices created by leading neighbors. However, in larger groups, these flow interactions caused chaos and collisions, making it difficult to maintain formation. Mathematical modeling was used to further understand the underlying forces driving these experimental results, revealing a non-reciprocal interaction that leads to wild oscillations among group members.
The study introduced the concept of “flonons,” which are waves of oscillations that travel through the group, causing later members to crash together. These waves are similar to phonons in material physics, which represent vibrational waves in systems of masses linked by springs. The research suggests that birds in an orderly flock can be compared to atoms in a crystal lattice, highlighting intriguing connections between biological and material physics. The team’s findings open up new avenues for studying the dynamics of collective animal behavior and their implications for various fields, including transportation, energy, and material science.
By uncovering the aerodynamic interactions that influence the organization of flying groups, the study provides valuable insights into the mechanisms that allow birds to fly in formation. Understanding how birds coordinate their movements in the air can lead to innovations in transportation and energy technologies that take inspiration from nature. The research also has broader implications for the study of collective animal behavior and the dynamics of group formations in different species. Overall, the study expands our knowledge of wildlife behavior and offers potential applications in various scientific disciplines.
The research team included mathematicians from New York University and École Polytechnique Paris who collaborated on the study published in Nature Communications. The work was supported by grants from the National Science Foundation, highlighting the importance of interdisciplinary research in advancing our understanding of complex biological phenomena. By combining experimental observations with mathematical modeling, the researchers were able to uncover the intricate aerodynamic interactions that underlie the coordinated movements of birds in flight. This study represents a significant contribution to the field of collective animal behavior and highlights the potential for future research to explore the fascinating dynamics of group formations in the natural world.
