Flash expansion and the repulsive herd

Romey, William L.; Smith, Amy L.; Buhl, Jérôme

doi:10.1016/j.anbehav.2015.09.017

Cited by 11 publications

(7 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Whether prey escape by considering the predator's position or its heading is unclear. In fish schools and insect swarms, individuals are supposed to avoid the position of the predator [48,56]. Homing pigeons instead were observed to turn away from its heading [24].…”

Section: Plos Computational Biologymentioning

confidence: 99%

Self-organization of collective escape in pigeon flocks

et al. 2022

View full text Add to dashboard Cite

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.

show abstract

Section: Plos Computational Biologymentioning

confidence: 99%

Self-organization of collective escape in pigeon flocks

et al. 2022

View full text Add to dashboard Cite

show abstract

“…First, more complex patterns, such as vacuoles and agitation waves may require larger flock sizes [ 2 , 26 ]. Secondly, the large body size of pigeons and their low manoeuvrability [ 86 , 101 , 102 ] may prevent them from executing the sharp turns involved in a flash expansion [ 26 , 103 ]. Thirdly, the slower attack of the artificial predator (RobotFalcon) in comparison to a real falcon [ 2 ] may prevent some patterns that depend on the quick increase in the proximity to the predator to emerge [ 84 , 87 , 97 ].…”

Section: Discussionmentioning

confidence: 99%

Emergence of splits and collective turns in pigeon flocks under predation

et al. 2022

View full text Add to dashboard Cite

Complex patterns of collective behaviour may emerge through self-organization, from local interactions among individuals in a group. To understand what behavioural rules underlie these patterns, computational models are often necessary. These rules have not yet been systematically studied for bird flocks under predation. Here, we study airborne flocks of homing pigeons attacked by a robotic falcon, combining empirical data with a species-specific computational model of collective escape. By analysing GPS trajectories of flocking individuals, we identify two new patterns of collective escape: early splits and collective turns, occurring even at large distances from the predator. To examine their formation, we extend an agent-based model of pigeons with a ‘discrete’ escape manoeuvre by a single initiator, namely a sudden turn interrupting the continuous coordinated motion of the group. Both splits and collective turns emerge from this rule. Their relative frequency depends on the angular velocity and position of the initiator in the flock: sharp turns by individuals at the periphery lead to more splits than collective turns. We confirm this association in the empirical data. Our study highlights the importance of discrete and uncoordinated manoeuvres in the collective escape of bird flocks and advocates the systematic study of their patterns across species.

show abstract

“…Whether prey escape by minding the predator’s position or its heading is unclear. In fish schools and insect swarms, individuals are supposed to avoid the position of the predator [42, 43]. Homing pigeons instead were observed to turn away from its heading [24].…”

Section: Discussionmentioning

confidence: 99%

Self-organization of collective escape in pigeon flocks

Papadopoulou

Hildenbrandt

Sankey

et al. 2021

Preprint

View full text Add to dashboard Cite

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.

show abstract

Flash expansion and the repulsive herd

Cited by 11 publications

References 49 publications

Self-organization of collective escape in pigeon flocks

Self-organization of collective escape in pigeon flocks

Emergence of splits and collective turns in pigeon flocks under predation

Self-organization of collective escape in pigeon flocks

Contact Info

Product

Resources

About