Data from: Testing the stability of behavioural coping style across stress contexts in the Trinidadian guppy

Within populations, individuals can vary in stress response, a
multivariate phenomenon comprising neuroendocrine, physiological and
behavioural traits. Verbal models of individual stress “coping style” have
proposed that the behavioural component of this variation can be described
as a single axis, with each individual's coping style being
consistent across time and stress contexts. Focusing on this behavioural
component of stress response and combining repeated measures of multiple
traits with a novel multivariate modelling framework, we test for the
existence of coping style variation and assess its stability across
contexts in the Trinidadian guppy (Poecilia reticulata). Specifically, we
test the following hypotheses: (1) there exists repeatable
among-individual behavioural (co)variation (“personality”) within a mild
stress context consistent with a risk-averse–risk-prone continuum of
behavioural coping style, (2) there is population-level plasticity in
behaviour as a function of stressor severity, (3) there is
among-individual variation in plasticity (i.e. IxE), and (4) the presence
of IxE reduces cross-context stability of behavioural coping style. We
found significant repeatable among-individual behavioural (co)variation in
the mild stress context (open field trial), represented as an I matrix.
However, I was not readily described by a simple risk-averse–risk-prone
continuum as posited by the original coping style model. We also found
strong evidence for population-level changes in mean behaviour with
increasing stressor severity (simulated avian and piscine predation
risks). Single-trait analyses did show the presence of
individual-by-environment interactions (IxE), as among-individual
cross-context correlations were significantly less than +1. However,
multitrait analysis revealed the consequences of this plasticity variation
were minimal. Specifically, we found little evidence for changes in the
structure of I between mild and moderate stress contexts overall, and only
minor changes between the two moderate contexts (avian vs. piscine
predator). We show that a multivariate approach to assessing changes in
among-individual (co)variance across contexts can prevent the
over-interpretation of statistically significant, but small,
individual-by-environment effects. While behavioural flexibility enables
populations (and individuals) to respond rapidly to changes in the
environment, multivariate personality structure can be conserved strongly
across such contexts.