Exploring the consequences of social responsiveness on leadership using an interactive biomimetic robotic fish
Final Report Abstract
Individuals can differ consistently in how they respond to the behavior of their social partners and this project aimed at measuring social responsiveness using a biomimetic robot and to investigate the consequences of differences in social responsiveness on social interactions especially during leadership scenarios. We first established that consistent individual differences in behavior among individuals of the same species are an inevitable feature as we found even genetically identical (clonal) fish reared under near-identical laboratory conditions to show strong individual differences. Using our unique biomimetic fish robot – Robofish – we were able to precisely measure individual differences in social responsiveness which is not trivial as interacting individuals often mutually influence each other. Guppies, however, were consistent in their individual responses between a live companion and Robofish, and similar individual differences in response towards Robofish were maintained over repeated testing. We further showed that sexes did not differ in their responsiveness towards Robofish. However, when letting live fish interact with differentially-sized Robofish replicas that behaved identically we found a “bigger is better” pattern with larger replicas were more closely followed than smaller ones. We further applied our Robofish system in studies that investigated (i) social behavior of invasive fish populations in Germany as well as (ii) the evolution of social behavior in cave living fishes from Mexico. In a second step, we used closed-loop (interactive) Robofish that was programmed to always follow a live partner fish at the same speed to investigate how individual differences in the live fish’s movement speeds as well as the extreme social responsiveness of Robofish interact. We showed that guppies had very large and repeatable differences in their individual movement speeds that in turn shaped key collective behavioural patterns: higher individual speeds were strongly linked with leadership, lower cohesion, higher alignment, and better coordination of movement changes of the pairs. In summary, by closed-loop experiments of live guppies swimming with Robofish that always followed and copy its movements, we provide important new evidence that individual speed is a key, fundamental process that underlies the emergence of collective behavior especially when group members exhibit high social responsiveness. In a last step, we improved the closed-loop algorithm of Robofish in a way that it functioned as a leader of live fish with us being able to adjust its leadership effectiveness through increasing or decreasing some interaction distances. As proposed in theoretical models, the Robofish’s predefined interaction distances significantly affected the time a group needed to reach a goal area and the distance the live fish kept towards Robofish: a highly responsive Robofish (small interaction distance) took longer to reach its goal but live fish stayed closer to it as compared to a less responsive (larger interaction distance) Robofish. In summary, we exemplified that interactions with biomimetic robots are a useful tool to measure social responsiveness in live fish and also to test the consequences of individual differences in social responsiveness on collective behavioral patterns like leadership. In part, the Robofish system is now integrated into the Cluster of Excellence “EXC 2002: Science of Intelligence (SCIoI)” and our research was several times picked up by newspapers and journals with public outreach like “Leibniz” (Journal of Leibniz-Gemeinschaft) and “Albert” (Journal of Einstein Foundation).
Publications
- (2017) Individual differences in behaviour of clonal fish arise despite near-identical rearing conditions. Nature Communications 8:15361
Bierbach D, Laskowski KL, Wolf M
(See online at https://doi.org/10.1038/ncomms15361) - (2018) BioTracker: An open-source computer vision framework for visual animal tracking
Mönck HJ, Jörg A, von Falkenhausen T, Tanke J, Wild B, Dormagen D, Piotrowski J, Winklmayr C, Bierbach D, Landgraf T
- (2018) Dancing honey bee robot elicits dance-following and recruits foragers
Landgraf T, Bierbach D, Kirbach A, Cusing R, Oertel M, Lehmann K, Greggers U, Menzel R, Rojas R
- (2018) Insights into the social behavior of surface and cave-dwelling fish (Poecilia mexicana) in light and darkness through the use of a biomimetic robot. Frontiers in Robotics and AI 5:3
Bierbach D, Lukas J, Bergmann A, Elsner K, Höhne L, Weber C, Weimar N, Arias- Rodriguez L, Mönck HJ, Nguyen H, Romanczuk P, Landgraf T, Krause J
(See online at https://doi.org/10.3389/frobt.2018.00003) - (2018) Using a robotic fish to investigate individual differences in social responsiveness in the guppy. Royal Society Open Science 5:181026
Bierbach D, Landgraf T, Romanczuk P, Lukas J, Nguyen H, Wolf M, Krause J
(See online at https://doi.org/10.1098/rsos.181026) - (2019) Naturally clonal vertebrates are an untapped resource in ecology and evolution research. Nature Ecology & Evolution 3, 161-169
Laskowski KL, Doran C, Bierbach D, Krause J, Wolf M
(See online at https://doi.org/10.1038/s41559-018-0775-0) - (2020) Guppies prefer to follow large (robot) leaders irrespective of own size. Front. Bioeng. Biotechnol. 8:441
Bierbach D, Moenck HJ, Lukas J, Habedank M, Romanczuk P, Landgraf T, Krause J
(See online at https://doi.org/10.3389/fbioe.2020.00441) - (2020). Consistent behavioural syndromes across seasons in an invasive freshwater fish
Lukas J, Kalinkat G, Miesen FW, Landgraf T, Krause J, Bierbach D
(See online at https://doi.org/10.3389/fevo.2020.583670)
