title: Dynamics of among-individual behavioral variation over adult lifespan in a wild insect.
abstract: Investigating patterns of among and within-individual trait variation in populations is essential to understanding how selection shapes phenotypes. Behavior is often the most flexible aspect of the phenotype, and to understand how it is affected by selection, we need to examine how consistent individuals are. However, it is not well understood whether among-individual differences tend to remain consistent over lifetimes, or whether the behavior of individuals relative to one another varies over time. We examined the dynamics of 4 behavioral traits (tendency to leave a refuge, shyness, activity, and exploration) in a wild population of field crickets (Gryllus campestris). We tagged individuals and then temporarily removed them from their natural environment and tested them under laboratory conditions. All 4 traits showed among-individual variance in mean levels of expression across the adult lifespan, but no significant differences in how rapidly expression changed with age. For all traits, among-individual variance increased as individuals got older. Our findings reveal seldom examined changes in variance components over the adult lifetime of wild individuals. Such changes will have important implications for the relationship between behavioral traits, life-histories, and fitness and the consequences of selection on wild individuals.
authors.affiliation: Centre for Ecology and Conservation, University of Exeter , Treliever Road, Penryn TR109FE , UK and.
authors.forename: David N
authors.initials: DN
authors.lastname: Fisher
authors.affiliation: Centre for Ecology and Conservation, University of Exeter , Treliever Road, Penryn TR109FE , UK and ; Department of Biology-Ethology, University of Antwerp , Drie Eiken Campus, Universiteitsplein 1, 2610 Wilrijk (Antwerpen) , Belgium.
authors.forename: Morgan
authors.initials: M
authors.lastname: David
authors.affiliation: Centre for Ecology and Conservation, University of Exeter , Treliever Road, Penryn TR109FE , UK and.
authors.forename: Tom
authors.initials: T
authors.lastname: Tregenza
authors.affiliation: Centre for Ecology and Conservation, University of Exeter , Treliever Road, Penryn TR109FE , UK and.
authors.forename: Rolando
authors.initials: R
authors.lastname: Rodríguez-Muñoz
keywords: Gryllus; animal personality; behavioral reaction norms; plasticity; wild crickets.