Avalanches and spatio-temporal correlations in schooling fish

Moving animal groups transmit information through propagating waves or behavioral cascades, exhibiting characteristics akin to systems near a critical point from statistical physics. Using data from freely swimming schooling fish in an experimental tank,
we investigate spontaneous behavioral cascades involving turning avalanches, where large directional shifts propagate across the group. Our results identify power-law distributions and robust scale-free behaviour through data collapses and scaling relationships, confirming a necessary condition for criticality in fish schools.
We explore the biological function of turning avalanches and link them to collective decision-making processes in selecting a new movement direction for the school.
Spatial and temporal correlations in avalanches are explored using the concept of aftershocks from seismology, revealing clustering of avalanche events below a designated timescale and an Omori law with a faster decay rate than observed in earthquakes.