Social carry-over effects on non-social behavioral variation: mechanisms and consequences

Petri T Niemelã¤,Francesca Santostefano

doi:10.3389/fevo.2015.00049

Abstract

The field of animal personality is interested in decomposing behaviors into different levels of variation, with its present focus on the ecological and evolutionary causes and consequences of expressed variation. Recently the role of the social environment, i.e. social partners, has been suggested to affect behavioral variation and induce selection on animal personality. Social partner effects exist because characters of social partners (e.g. size, behavior), affect the behavioral expression of a focal individual. Here, we 1) first review the proximate mechanisms underlying the social partner effects on behavioral expression and the timescales at which such effects might take place. We then 2) discuss how within- and among-individual variation in single behaviors and covariation between multiple behaviors, caused by social partners, can carry-over to non-social behaviors expressed outside the social context. Finally, we 3) highlight evolutionary consequences of social carry-over effects to non-social behaviors and 4) suggest study designs and statistical approaches which can be applied to study the nature and evolutionary consequences of social carry-over effects on non-social behaviors. Understanding the proximate mechanisms underpinning the social partner effects is important since it opens a door for deeper understanding of how social environments can affect behavioral variation and covariation at multiple levels, and the evolution of non-social behaviors (i.e. exploration, activity, boldness) that are affected by social interactions.

Highlights

Phenotypes vary at multiple levels and research in the field of animal personality has highlighted the importance of distinguishing between behavioral variation that occurs among individuals (“personality”) vs. within individuals (“plasticity”) (Dingemanse et al, 2010; Dingemanse and Dochtermann, 2013)
Among-individual level variation has more recently come to the foreground in behavioral ecology and, whilst not necessarily predicted by traditional adaptive theory (Dall et al, 2004), it is widespread across the animal kingdom (Sih et al, 2004; Dingemanse and Wolf, 2010; Wolf and Weissing, 2010; Dall et al, 2012), and has major ecological and evolutionary consequences (Wolf and Weissing, 2012)
Within-Individual Variance: Plasticity When carry-over effects are underpinned by fast-changing states, like hormonal profiles or energy levels (Hsu et al, 2006; Coppens et al, 2010), and when focal individuals do not differ in the confronted social environment, social partners will affect the within-individual component of behavioral variance in nonsocial behaviors, expressed after social interactions (Figure 2)

Summary

Introduction

Phenotypes vary at multiple levels and research in the field of animal personality has highlighted the importance of distinguishing between behavioral variation that occurs among individuals (“personality”) vs. within individuals (“plasticity”) (Dingemanse et al, 2010; Dingemanse and Dochtermann, 2013). Social partners can affect the up- or down regulation of different state variables of a focal individual, like hormonal profiles, the level of energy, or body size, and affect the expressed behaviors of a focal individual through these proximate mechanisms (Hsu et al, 2006; Sachser et al, 2013; Wilson et al, 2013).

Results

Conclusion