Local interactions and their group-level consequences in flocking jackdaws
| Autor: | Guillam E. Mclvor, Kasper van der Vaart, Alex Thornton, Hangjian Ling, Nicholas T. Ouellette, Richard T. Vaughan |
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| Rok vydání: | 2019 |
| Předmět: |
Interaction forces
01 natural sciences General Biochemistry Genetics and Molecular Biology 03 medical and health sciences 0103 physical sciences Animals Behaviour 010306 general physics Social Behavior Group level 030304 developmental biology General Environmental Science Crows 0303 health sciences General Immunology and Microbiology Behavior Animal Flocking (behavior) General Medicine Potential energy Attraction United Kingdom Biomechanical Phenomena Group structure Geography Three dimensional imaging Classical mechanics Flight Animal Flock General Agricultural and Biological Sciences |
| Zdroj: | Proc Biol Sci |
| ISSN: | 1471-2954 |
| Popis: | As one of nature's most striking examples of collective behaviour, bird flocks have attracted extensive research. However, we still lack an understanding of the attractive and repulsive forces that govern interactions between individuals within flocks and how these forces influence neighbours' relative positions and ultimately determine the shape of flocks. We address these issues by analysing the three-dimensional movements of wild jackdaws ( Corvus monedula ) in flocks containing 2–338 individuals. We quantify the social interaction forces in large, airborne flocks and find that these forces are highly anisotropic. The long-range attraction in the direction perpendicular to the movement direction is stronger than that along it, and the short-range repulsion is generated mainly by turning rather than changing speed. We explain this phenomenon by considering wingbeat frequency and the change in kinetic and gravitational potential energy during flight, and find that changing the direction of movement is less energetically costly than adjusting speed for birds. Furthermore, our data show that collision avoidance by turning can alter local neighbour distributions and ultimately change the group shape. Our results illustrate the macroscopic consequences of anisotropic interaction forces in bird flocks, and help to draw links between group structure, local interactions and the biophysics of animal locomotion. |
| Databáze: | OpenAIRE |
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