Collective motion is beautiful. We have all seen it when a school of fishes evades the attacks of a predator, or a flock of starlings performs a similar dance in the skies above Rome. But how does this work? How do the fish or the birds know where and when to move?
Collective motion has long been modeled with simple rules between neighboring individuals with astonishing results. Birds and fish seem to use very similar rules to move collectively. But still, there are many exceptions to these general rules. A fish swarm is composed of quite different individuals, all exhibiting variation in their behavior. Some swim slow and some fast, some lead the swarm, while others follow more often. Besides, collective motion often translates into group decisions, e.g. when all fish move to food source A rather than B. So, how do these individual differences influence the collective motion and collective decisions? How is information perceived by, and transmitted and processed within the group when there are so many different “personalities”?
Using a biomimetic fish robot we are able to test various hypotheses: we can make the Robofish thin or big, fast or slow, we can make it act risk-averse or adventurous, nervous or calm. This way we can uncouple the natural network of interactions and study the effects of cues over which we have full control. This way we can study the underlying mechanics of collective behavior in great detail and can understand better how other swarms, such as flocks or human groups reach a common goal with different personalities.
Leibniz Institute of Freshwater Ecology and Inland Fisheries and Humboldt University Berlin
Biorobotics Lab, Institute of Computer Science, Free University Berlin
Prof. Dr. Tim Landgraf, Hauke Mönck, Hai Nguyen, Angelika Szengel, Yanlei Lei, Victor Brekenfeld
Former Members (Thank you!): Rami Akkad, Stefan Forgo, Christoph Krüger, Jan Schneider, Joseph Schröer, Henrik Matzke, Romain Clément
We are thankful for the support of the Andrea-von-Braun Foundation who granted a PhD scholarship to Hauke Mönck.
Pawel Romanczuk and David Bierbach are funded by the German Research Foundation (DFG).