Critical population density triggers rapid formation of vast oceanic fish shoals.
Similarities in the behavior of diverse animal species that form large groups have motivated attempts to establish general principles governing animal group behavior. It has been difficult, however, to make quantitative measurements of the temporal and spatial behavior of extensive animal groups in the wild, such as bird flocks, fish shoals, and locust swarms. By quantifying the formation processes of vast oceanic fish shoals during spawning, we show that (i) a rapid transition from disordered to highly synchronized behavior occurs as population density reaches a critical value; (ii) organized group migration occurs after this transition; and (iii) small sets of leaders significantly influence the actions of much larger groups. Each of these findings confirms general theoretical predictions believed to apply in nature irrespective of animal species.
Makris
Nicholas C
NC
Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. makris@mit.edu
Ratilal
Purnima
P
Jagannathan
Srinivasan
S
Gong
Zheng
Z
Andrews
Mark
M
Bertsatos
Ioannis
I
Godø
Olav Rune
OR
Nero
Redwood W
RW
Jech
J Michael
JM