scholarly journals Self-organization of collective escape in pigeon flocks

2022 ◽  
Vol 18 (1) ◽  
pp. e1009772
Author(s):  
Marina Papadopoulou ◽  
Hanno Hildenbrandt ◽  
Daniel W. E. Sankey ◽  
Steven J. Portugal ◽  
Charlotte K. Hemelrijk
Keyword(s):  
Collective Behavior ◽  
Computational Models ◽  
Collective Motion ◽  
Specific Model ◽  
Self Organization ◽  
Behavioral Rules ◽  
Bearing Angle ◽  
Gps Trajectories ◽  
Group Members ◽  
Species Specific

Bird flocks under predation demonstrate complex patterns of collective escape. These patterns may emerge by self-organization from local interactions among group-members. Computational models have been shown to be valuable for identifying what behavioral rules may govern such interactions among individuals during collective motion. However, our knowledge of such rules for collective escape is limited by the lack of quantitative data on bird flocks under predation in the field. In the present study, we analyze the first GPS trajectories of pigeons in airborne flocks attacked by a robotic falcon in order to build a species-specific model of collective escape. We use our model to examine a recently identified distance-dependent pattern of collective behavior: the closer the prey is to the predator, the higher the frequency with which flock members turn away from it. We first extract from the empirical data of pigeon flocks the characteristics of their shape and internal structure (bearing angle and distance to nearest neighbors). Combining these with information on their coordination from the literature, we build an agent-based model adjusted to pigeons’ collective escape. We show that the pattern of turning away from the predator with increased frequency when the predator is closer arises without prey prioritizing escape when the predator is near. Instead, it emerges through self-organization from a behavioral rule to avoid the predator independently of their distance to it. During this self-organization process, we show how flock members increase their consensus over which direction to escape and turn collectively as the predator gets closer. Our results suggest that coordination among flock members, combined with simple escape rules, reduces the cognitive costs of tracking the predator while flocking. Such escape rules that are independent of the distance to the predator can now be investigated in other species. Our study showcases the important role of computational models in the interpretation of empirical findings of collective behavior.

scholarly journals Self-organization of collective escape in pigeon flocks

2021 ◽  
Author(s):  
Marina Papadopoulou ◽  
Hanno Hildenbrandt ◽  
Daniel W.E. Sankey ◽  
Steven J. Portugal ◽  
Charlotte K. Hemelrijk
Keyword(s):  
Collective Behavior ◽  
Computational Models ◽  
Collective Motion ◽  
Specific Model ◽  
Self Organization ◽  
Predator Prey ◽  
Behavioral Rules ◽  
Bearing Angle ◽  
Species Specific

Bird flocks under predation demonstrate complex patterns of collective escape. These patterns may emerge by self-organization from simple interactions among group-members. Computational models have been shown to be valuable for identifying the behavioral rules that may govern these interactions among individuals during collective motion. However, our knowledge of such rules for collective escape is limited by the lack of quantitative data on bird flocks under predation in the field. In the present study, we analyze the first dataset of GPS trajectories of pigeons in airborne flocks attacked by a robotic falcon in order to build a species-specific model of collective escape. We use our model to examine a recently identified distance-dependent pattern of collective behavior that shows an increase in the escape frequency of pigeons when the predator is closer. We first extract from the empirical data the characteristics of pigeon flocks regarding their shape and internal structure (bearing angle and distance to nearest neighbours). Combining these with information on their coordination from the literature, we build an agent-based model tuned to pigeons' collective escape. We show that the pattern of increased escape frequency closer to the predator arises without flock-members prioritizing escape when the predator is near. Instead, it emerges through self-organization from an individual rule of predator-avoidance that is independent of predator-prey distance. During this self-organization process, we uncover a role of hysteresis and show that flock members increase their consensus over the escape direction and turn collectively as the predator gets closer. Our results suggest that coordination among flock-members, combined with simple escape rules, reduces the cognitive costs of tracking the predator. Such rules that are independent of predator-prey distance can now be examined in other species. Finally, we emphasize on the important role of computational models in the interpretation of empirical findings of collective behavior.

scholarly journals Conformity in the collective: differences in hunger affect individual and group behavior in a shoaling fish

2019 ◽  
Vol 30 (4) ◽  
pp. 968-974 ◽  
Author(s):  
Alexander D M Wilson ◽  
Alicia L J Burns ◽  
Emanuele Crosato ◽  
Joseph Lizier ◽  
Mikhail Prokopenko ◽  
...  
Keyword(s):  
Collective Behavior ◽  
Nearest Neighbor ◽  
Collective Motion ◽  
Internal State ◽  
Group Behavior ◽  
Fundamental Interest ◽  
Individual Level ◽  
Group Members ◽  
The Individual ◽  
Nearest Neighbor Distances

Abstract Animal groups are often composed of individuals that vary according to behavioral, morphological, and internal state parameters. Understanding the importance of such individual-level heterogeneity to the establishment and maintenance of coherent group responses is of fundamental interest in collective behavior. We examined the influence of hunger on the individual and collective behavior of groups of shoaling fish, x-ray tetras (Pristella maxillaris). Fish were assigned to one of two nutritional states, satiated or hungry, and then allocated to 5 treatments that represented different ratios of satiated to hungry individuals (8 hungry, 8 satiated, 4:4 hungry:satiated, 2:6 hungry:satiated, 6:2 hungry:satiated). Our data show that groups with a greater proportion of hungry fish swam faster and exhibited greater nearest neighbor distances. Within groups, however, there was no difference in the swimming speeds of hungry versus well-fed fish, suggesting that group members conform and adapt their swimming speed according to the overall composition of the group. We also found significant differences in mean group transfer entropy, suggesting stronger patterns of information flow in groups comprising all, or a majority of, hungry individuals. In contrast, we did not observe differences in polarization, a measure of group alignment, within groups across treatments. Taken together these results demonstrate that the nutritional state of animals within social groups impacts both individual and group behavior, and that members of heterogenous groups can adapt their behavior to facilitate coherent collective motion.

scholarly journals Emergence of self-organized multivortex states in flocks of active rollers

2020 ◽  
Vol 117 (18) ◽  
pp. 9706-9711 ◽  
Author(s):  
Koohee Han ◽  
Gašper Kokot ◽  
Oleh Tovkach ◽  
Andreas Glatz ◽  
Igor S. Aranson ◽  
...  
Keyword(s):  
Computational Modeling ◽  
Collective Behavior ◽  
Rotational Motion ◽  
Collective Motion ◽  
Self Organization ◽  
Design Strategies ◽  
Vortex Phase ◽  
Active Elements ◽  
Self Organized ◽  
Dynamic Materials

Active matter, both synthetic and biological, demonstrates complex spatiotemporal self-organization and the emergence of collective behavior. A coherent rotational motion, the vortex phase, is of great interest because of its ability to orchestrate well-organized motion of self-propelled particles over large distances. However, its generation without geometrical confinement has been a challenge. Here, we show by experiments and computational modeling that concentrated magnetic rollers self-organize into multivortex states in an unconfined environment. We find that the neighboring vortices more likely occur with the opposite sense of rotation. Our studies provide insights into the mechanism for the emergence of coherent collective motion on the macroscale from the coupling between microscale rotation and translation of individual active elements. These results may stimulate design strategies for self-assembled dynamic materials and microrobotics.

scholarly journals Collective Motion in Human Crowds

2018 ◽  
Vol 27 (4) ◽  
pp. 232-240 ◽  
Author(s):  
William H. Warren
Keyword(s):  
Collective Behavior ◽  
Collective Motion ◽  
Local Level ◽  
Self Organization ◽  
Coherent Motion ◽  
Global Level ◽  
Crowd Behavior ◽  
Local Interactions ◽  
Fish Schools ◽  
Emergency Situations

The balletic motion of bird flocks, fish schools, and human crowds is believed to emerge from local interactions between individuals in a process of self-organization. The key to explaining such collective behavior thus lies in understanding these local interactions. After decades of theoretical modeling, experiments using virtual crowds and analysis of real crowd data are enabling us to decipher the “rules of engagement” governing these interactions. On the basis of such results, my students and I built a dynamical model of how a pedestrian aligns his or her motion with that of a neighbor and how these binary interactions are combined within a neighborhood of interaction. Computer simulations of the model generate coherent motion at the global level and reproduce individual trajectories at the local level. This approach has yielded the first experiment-driven, bottom-up model of collective motion, providing a basis for understanding more complex patterns of crowd behavior in both everyday and emergency situations.

Collective behavior states in animal groups

2017 ◽  
Vol 31 (06) ◽  
pp. 1750054 ◽  
Author(s):  
Dorílson S. Cambui
Keyword(s):  
Collective Behavior ◽  
High Speed ◽  
Collective Motion ◽  
Formation Flight ◽  
Agent Based Model ◽  
Stochastic Variable ◽  
Motion Direction ◽  
Agent Based ◽  
Behavioral Rules ◽  
Collective Rotation

In this work, we study some states of collective behavior observed in groups of animals. For this end we consider an agent-based model with biologically motivated behavioral rules where the speed is treated as an independent stochastic variable, and the motion direction is adjusted in accord with alignment and attractive interactions. Four types of collective behavior have been observed: disordered motion, collective rotation, coherent collective motion, and formation flight. We investigate the case when transitions between collective states depend on both the speed and the attraction between individuals. Our results show that, to any size of the attraction, small speeds are associated to the coherent collective motion, while collective rotation is more and more pronounced for high speed since the attraction radius is large enough.

scholarly journals Larval zebrafish exhibit collective motion behaviors in constrained spaces

2021 ◽  
Author(s):  
Haider Zaki ◽  
Enkeleida Lushi ◽  
Kristen E Severi
Keyword(s):  
Social Interactions ◽  
Developmental Stage ◽  
Collective Behavior ◽  
Physical Environment ◽  
Collective Motion ◽  
Model System ◽  
Self Organization ◽  
Physical Mechanisms ◽  
Larval Zebrafish ◽  
Advance Knowledge

Collective behavior may be elicited or can spontaneously emerge by a combination of interactions with the physical environment and conspecifics moving within that environment. To investigate the relative contributions of these factors in a small millimeter-scale swimming organism, we observed larval zebrafish, interacting at varying densities under circular confinement. Our aim was to understand the biological and physical mechanisms acting on these larvae as they swim together inside circular confinements. If left undisturbed, larval zebrafish swim intermittently in a burst and coast manner and are socially independent at this developmental stage, before shoaling behavioral onset. We report here our analysis of a new observation for this well-studied species: in circular confinement and at sufficiently high densities, the larvae collectively circle rapidly alongside the boundary. This is a new physical example of self-organization of mesoscale living active matter driven by boundaries and environment geometry. We believe this is a step forward toward using a prominent biological model system in a new interdisciplinary context to advance knowledge of the physics of social interactions.

scholarly journals Colony expansions underlie the evolution of army ant mass raiding

2020 ◽  
Author(s):  
Vikram Chandra ◽  
Asaf Gal ◽  
Daniel J. C. Kronauer
Keyword(s):  
Collective Behavior ◽  
Close Relative ◽  
Alternative Mechanism ◽  
Scaling Effects ◽  
Army Ants ◽  
Evolutionary Transitions ◽  
Army Ant ◽  
Behavioral Rules ◽  
Group Members ◽  
Fine Tune

ABSTRACTCollective behavior emerges from local interactions between group members, and natural selection can fine-tune these interactions to achieve different collective outcomes. However, at least in principle, collective behavior can also evolve via changes in group-level parameters. Here, we show that army ant mass raiding, an iconic collective behavior in which many thousands of ants spontaneously leave the nest to go hunting, has evolved from group raiding, in which a scout directs a much smaller group of ants to a specific target. We describe the structure of group raids in the clonal raider ant, a close relative of army ants. We find that the coarse structure of group raids and mass raids is highly conserved, and that army ants and their relatives likely follow similar behavioral rules, despite the fact that their raids differ strikingly in overall appearance. By experimentally increasing colony size in the clonal raider ant, we show that mass raiding gradually emerges from group raiding without altering individual behavioral rules. This suggests a simple mechanism for the evolution of army ant mass raids, and more generally that scaling effects may provide an alternative mechanism for evolutionary transitions in complex collective behavior.

Density-dependent and species-specific effects on self-organization modulate the resistance of mussel bed ecosystems to hydrodynamic stress

2021 ◽  
Author(s):  
Gerardo I. Zardi ◽  
Katy Rebecca Nicastro ◽  
Christopher D. McQuaid ◽  
Monique de Jager ◽  
Johan van de Koppel ◽  
...  
Keyword(s):  
Self Organization ◽  
Mussel Bed ◽  
Hydrodynamic Stress ◽  
Density Dependent ◽  
Specific Effects ◽  
Species Specific

Numerical electrophoretic analysis and the behavior of larval proteins among Aedes mosquitoes

1979 ◽  
Vol 57 (5) ◽  
pp. 979-982 ◽  
Author(s):  
Emmanuel C. Igbokwe
Keyword(s):  
Collective Behavior ◽  
Protein Complex ◽  
Related Species ◽  
Electrophoretic Analysis ◽  
Behavioral Profile ◽  
Aedes Mosquitoes ◽  
Molecular Behavior ◽  
Interspecific Divergence ◽  
Molecular Divergence ◽  
Species Specific

Species-specific patterns of larval protein electrophoregrams obtained among three species of Aedes mosquitoes were analyzed numerically. A behavioral profile was derived and illustrated for the larval protein complex of each species. Patterns of interspecific divergence in molecular behavior not detectable otherwise from the electrophoregrams were evident in the behavioral profiles of the proteins. The degree of electrophoretic correspondence obtained from the number of shared fractions among the species differs from that derived from the collective behavior of proteins. The numerical and graphic approach to the interpretation of protein electrophoregrams offers another parameter for gauging molecular divergence among related species of insects.

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