Animal personality and pace-of-life syndromes: do fast-exploring fairy-wrens die young?

Timon Van Asten,Michelle L Hall,Michael J L Magrath,Andrew C Katsis,Raoul A Mulder,Niels J Dingemanse

doi:10.3389/fevo.2015.00028

Abstract

The pace-of-life syndrome (POLS) hypothesis for animal personality proposes that variation among individuals in life-history strategies is associated with consistent differences in behavior. We tested predictions of this hypothesis in the superb fairy-wren, Malurus cyaneus, by investigating long-term individual differences in risk-related behaviors (latency to enter a novel artificial environment, exploration, activity and response to mirror image stimulation) and survival. We found consistent differences between individuals in these behaviors (adjusted repeatability of exploration of artificial novel environment = 0.37). Individual differences were consistent over several years and bi-variate analyses showed a significant among-individual correlation (‘behavioral syndrome’) between exploration behavior at two life stages (young adult and old adult). Docility at the nestling stage predicted exploration behavior of juveniles. Behavioral traits measured in a risky context were correlated with one another, forming a behavioral syndrome of coping strategies ranging from ‘proactive’ to ‘reactive’. Nestlings that were more active and exploratory in isolation were less docile during handling, while adults that entered the artificial environment fast were more exploratory, active, and aggressive in the artificial environment. Exploration behavior increased within individuals as they aged and when they were in poorer condition, consistent with expectations of more risk-prone behavior with lower residual reproductive value (reduced ‘asset protection’). Risk-related behavior predicted the probability of apparent survival: more exploratory individuals were less likely to be present in the population twelve months later. Our findings suggest that, consistent with the predictions of the POLS hypothesis, individual variation in survival is associated with consistent individual differences in risk-related behavior that are maintained long-term and span developmental boundaries.

Highlights

Animals differ in their pace of life, from those that are long-lived with slow reproductive rates, to those that “live fast and die young.” This “slow-fast” spectrum of life-history strategies has been well studied across species (Roff, 2002), but has only recently begun to attract attention as an explanation for behavioral differences among individuals within populationsFairy-wren personality and survival of the same species (Biro and Stamps, 2008; Smith and Blumstein, 2008; Reale et al, 2010)
We focused on exploration behavior, since it was the behavioral trait with the highest repeatability, and considered year and sex as additional explanatory factors in the model
Consistent Individual Differences in Risk-Related Behavior The behavior of superb fairy-wrens in an artificial novel environment showed considerable variation (Supplementary Material Figure S2 shows frequency distributions of behaviors), with a significant proportion of this variation due to consistent differences between individuals in their average behavior (Table 1 shows repeatability values adjusted for testing conditions)

Summary

Introduction

Animals differ in their pace of life, from those that are long-lived with slow reproductive rates, to those that “live fast and die young.” This “slow-fast” spectrum of life-history strategies has been well studied across species (Roff, 2002), but has only recently begun to attract attention as an explanation for behavioral differences among individuals within populationsFairy-wren personality and survival of the same species (Biro and Stamps, 2008; Smith and Blumstein, 2008; Reale et al, 2010). Animals differ in their pace of life, from those that are long-lived with slow reproductive rates, to those that “live fast and die young.” This “slow-fast” spectrum of life-history strategies has been well studied across species (Roff, 2002), but has only recently begun to attract attention as an explanation for behavioral differences among individuals within populations. The POLS hypothesis relates to behavioral traits that promote particular life-history strategies (Reale et al, 2010), predicting long-term repeatability of behavioral traits such as boldness, aggression, exploration, and activity, where these are associated with shorter lifespans or increased risk of mortality

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Conclusion