title: Emergence of collective strategies in a prey-predator game model.
abstract: The emergence of collective strategies in a prey-predator system is studied. We use the term "collective" in the sense of the collective motion of defense or attack often found in behaviors of animal groups. In our prey-predator system, both prey and predators move around on a two-dimensional plane, interacting by playing a game; predators can score by touching the backside of a prey. Thresholds are assumed for the scores of both prey and predators. The species with the higher scores can reproduce more, and that with the lower scores will be diminished. As a result, strategies as collective motions are observed; these consist of rotating cluster motions, line formations, disordered but one-way marching, and random swarming. In particular, the strategy of random swarming encourages symbiosis in the sense that it is associated with a low extinction probability for the whole system.
authors.affiliation: Institute of Physics, Graduate School of Arts and Sciences, University of Tokyo, Japan.
authors.forename: S I
authors.initials: SI
authors.lastname: Nishimura
authors.forename: T
authors.initials: T
authors.lastname: Ikegami
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005716:Game Theory; D008433:Mathematics; D008954:Models, Biological; D011157:Population Dynamics; D011235:Predatory Behavior; D013559:Symbiosis