title: From disorder to order in marching locusts.
abstract: Recent models from theoretical physics have predicted that mass-migrating animal groups may share group-level properties, irrespective of the type of animals in the group. One key prediction is that as the density of animals in the group increases, a rapid transition occurs from disordered movement of individuals within the group to highly aligned collective motion. Understanding such a transition is crucial to the control of mobile swarming insect pests such as the desert locust. We confirmed the prediction of a rapid transition from disordered to ordered movement and identified a critical density for the onset of coordinated marching in locust nymphs. We also demonstrated a dynamic instability in motion at densities typical of locusts in the field, in which groups can switch direction without external perturbation, potentially facilitating the rapid transfer of directional information.
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK. camille.buhl@adelaide.edu.au
authors.forename: C
authors.initials: C
authors.lastname: Buhl
authors.forename: D J T
authors.initials: DJ
authors.lastname: Sumpter
authors.forename: I D
authors.initials: ID
authors.lastname: Couzin
authors.forename: J J
authors.initials: JJ
authors.lastname: Hale
authors.forename: E
authors.initials: E
authors.lastname: Despland
authors.forename: E R
authors.initials: ER
authors.lastname: Miller
authors.forename: S J
authors.initials: SJ
authors.lastname: Simpson
mesh_terms: D000818:Animals; D006110:Grasshoppers / Q000502:physiology*; D008399:Mass Behavior; D008954:Models, Biological; D009068:Movement; D011156:Population Density