title: Evidence for a pervasive 'idling-mode' activity template in flying and pedestrian insects.
abstract: Understanding the complex movement patterns of animals in natural environments is a key objective of 'movement ecology'. Complexity results from behavioural responses to external stimuli but can also arise spontaneously in their absence. Drawing on theoretical arguments about decision-making circuitry, we predict that the spontaneous patterns will be scale-free and universal, being independent of taxon and mode of locomotion. To test this hypothesis, we examined the activity patterns of the European honeybee, and multiple species of noctuid moth, tethered to flight mills and exposed to minimal external cues. We also reanalysed pre-existing data for Drosophila flies walking in featureless environments. Across these species, we found evidence of common scale-invariant properties in their movement patterns; pause and movement durations were typically power law distributed over a range of scales and characterized by exponents close to 3/2. Our analyses are suggestive of the presence of a pervasive scale-invariant template for locomotion which, when acted on by environmental cues, produces the movements with characteristic scales observed in nature. Our results indicate that scale-finite complexity as embodied, for instance, in correlated random walk models, may be the result of environmental cues overriding innate behaviour, and that scale-free movements may be intrinsic and not limited to 'blind' foragers as previously thought.
authors.affiliation: Rothamsted Research , Harpenden , Hertfordshire AL5 2JQ, UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Reynolds
authors.affiliation: Rothamsted Research , Harpenden , Hertfordshire AL5 2JQ, UK ; Department of Biology , University of York , York YO10 5DD, UK.
authors.forename: Hayley B C
authors.initials: HB
authors.lastname: Jones
authors.affiliation: Department of Biology , University of York , York YO10 5DD, UK.
authors.forename: Jane K
authors.initials: JK
authors.lastname: Hill
authors.affiliation: Rothamsted Research , Harpenden , Hertfordshire AL5 2JQ, UK ; Lancaster Environment Centre , Lancaster University , Lancaster LA1 4YQ, UK.
authors.forename: Aislinn J
authors.initials: AJ
authors.lastname: Pearson
authors.affiliation: Lancaster Environment Centre , Lancaster University , Lancaster LA1 4YQ, UK.
authors.forename: Kenneth
authors.identifier: 0000-0001-5264-6522
authors.initials: K
authors.lastname: Wilson
authors.affiliation: Rothamsted Research , Harpenden , Hertfordshire AL5 2JQ, UK ; School of Biological and Chemical Sciences , Queen Mary University of London , London E1 4NS, UK.
authors.forename: Stephan
authors.initials: S
authors.lastname: Wolf
authors.affiliation: Rothamsted Research , Harpenden , Hertfordshire AL5 2JQ, UK.
authors.forename: Ka S
authors.initials: KS
authors.lastname: Lim
authors.affiliation: Rothamsted Research , Harpenden , Hertfordshire AL5 2JQ, UK ; Natural Resources Institute , University of Greenwich , Chatham, Kent ME4 4TB, UK.
authors.forename: Don R
authors.initials: DR
authors.lastname: Reynolds
authors.affiliation: Rothamsted Research , Harpenden , Hertfordshire AL5 2JQ, UK ; Environment and Sustainability Institute , University of Exeter , Penryn, Cornwall TR10 9EZ, UK.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Chapman
keywords: Lévy flights; behavioural bursts; intermittent locomotion; power-law distributions; spontaneous movement patterns