title: Variability in individual activity bursts improves ant foraging success.
abstract: Using experimental and computational methods, we study the role of behavioural variability in activity bursts (or temporal activity patterns) for individual and collective regulation of foraging in A. senilis ants. First, foraging experiments were carried out under special conditions (low densities of ants and food and absence of external cues or stimuli) where individual-based strategies are most prevalent. By using marked individuals and recording all foraging trajectories, we were then able to precisely quantify behavioural variability among individuals. Our main conclusions are that (i) variability of ant trajectories (turning angles, speed, etc.) is low compared with variability of temporal activity profiles, and (ii) this variability seems to be driven by plasticity of individual behaviour through time, rather than the presence of fixed behavioural stereotypes or specialists within the group. The statistical measures obtained from these experimental foraging patterns are then used to build a general agent-based model (ABM) which includes the most relevant properties of ant foraging under natural conditions, including recruitment through pheromone communication. Using the ABM, we are able to provide computational evidence that the characteristics of individual variability observed in our experiments can provide a functional advantage (in terms of foraging success) to the group; thus, we propose the biological basis underpinning our observations. Altogether, our study reveals the potential utility of experiments under simplified (laboratory) conditions for understanding information-gathering in biological systems.
authors.affiliation: Grup de Física Estadística, Departament de Física. Facultat de Ciències, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain daniel.campos@uab.es.
authors.forename: Daniel
authors.identifier: 0000-0003-1982-3288
authors.initials: D
authors.lastname: Campos
authors.affiliation: Centre de Recerca en Ecologia i Aplicacions Forestals (CREAF), Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.|Theoretical and Computational Ecology Lab (CEAB-CSIC), Blanes 17300, Spain.|Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain.
authors.forename: Frederic
authors.initials: F
authors.lastname: Bartumeus
authors.affiliation: Grup de Física Estadística, Departament de Física. Facultat de Ciències, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.
authors.forename: Vicenç
authors.initials: V
authors.lastname: Méndez
authors.affiliation: Departamento de Física, Universidade Federal do Ceará, 60451-970, Fortaleza, Ceará, Brazil.
authors.forename: José S
authors.initials: JS
authors.lastname: Andrade
authors.affiliation: Centre de Recerca en Ecologia i Aplicacions Forestals (CREAF), Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Espadaler
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D003198:Computer Simulation; D008954:Models, Biological; D012919:Social Behavior
keywords: agent-based models; random walk; search theory