title: Ergodic directional switching in mobile insect groups.
abstract: We obtain a Fokker-Planck equation describing experimental data on the collective motion of locusts. The noise is of internal origin and due to the discrete character and finite number of constituents of the swarm. The stationary probability distribution shows a rich phenomenology including nonmonotonic behavior of several order and disorder transition indicators in noise intensity. This complex behavior arises naturally as a result of the randomness in the system. Its counterintuitive character challenges standard interpretations of noise induced transitions and calls for an extension of this theory in order to capture the behavior of certain classes of biologically motivated models. Our results suggest that the collective switches of the group's direction of motion might be due to a random ergodic effect and, as such, they are inherent to group formation.
authors.affiliation: ICMAT, CSIC-UAM-UC3M-UCM, Departamento de Matemáticas, Facultad de Ciencias, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Escudero
authors.forename: Christian A
authors.initials: CA
authors.lastname: Yates
authors.forename: Jerome
authors.initials: J
authors.lastname: Buhl
authors.forename: Iain D
authors.initials: ID
authors.lastname: Couzin
authors.forename: Radek
authors.initials: R
authors.lastname: Erban
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Kevrekidis
authors.forename: Philip K
authors.initials: PK
authors.lastname: Maini
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001683:Biological Clocks / Q000502:physiology*; D003198:Computer Simulation; D003441:Crowding; D005426:Flight, Animal / Q000502:physiology*; D006110:Grasshoppers / Q000502:physiology*; D008954:Models, Biological; D015233:Models, Statistical