Birds and Fish Move Like Tiny Springy Crystals

Scientists at New York University have discovered that the collective motion of birds flying in lines and fish swimming in schools mirrors the behavior of a soft crystal. In these materials, tiny “atoms” occupy evenly spaced lattice points and are connected by flexible bonds that can stretch or bend. The researchers propose that each bird or fish functions as an atom, holding the group together while permitting rapid adjustments.

Key Findings

• Collective Behavior
  The motion of these animals is governed by hydrodynamic and aerodynamic forces—principles also critical in the design of aircraft, cars, robots, and energy devices.

• Elastic Material View
  By treating the group as an elastic material, engineers could gain insights into controlling similar systems in technology.

• Mathematical Model
  A model replicating soft‑crystal behavior was built. It predicts shape changes under varying temperature or pressure, and aligns with past experiments using 3‑D printed flappers that simulate bird wings in water. The flappers lined up and moved as expected, validating the new model.

• Fragility vs. Responsiveness
  While these formations are fragile—small disturbances can alter their shape—they become highly responsive to external forces such as wind, currents, or predators.

Funding

The research was supported by a grant from the National Science Foundation.