Individual differences in behavioural plasticities

Abstract

Interest in individual differences in animal behavioural plasticities has surged in recent years, but research in this area has been hampered by semantic confusion as different investigators use the same terms (e.g. plasticity, flexibility, responsiveness) to refer to different phenomena. The first goal of this review is to suggest a framework for categorizing the many different types of behavioural plasticities, describe examples of each, and indicate why using reversibility as a criterion for categorizing behavioural plasticities is problematic. This framework is then used to address a number of timely questions about individual differences in behavioural plasticities. One set of questions concerns the experimental designs that can be used to study individual differences in various types of behavioural plasticities. Although within-individual designs are the default option for empirical studies of many types of behavioural plasticities, in some situations (e.g. when experience at an early age affects the behaviour expressed at subsequent ages), 'replicate individual' designs can provide useful insights into individual differences in behavioural plasticities. To date, researchers using within-individual and replicate individual designs have documented individual differences in all of the major categories of behavioural plasticities described herein. Another important question is whether and how different types of behavioural plasticities are related to one another. Currently there is empirical evidence that many behavioural plasticities [e.g. contextual plasticity, learning rates, IIV (intra-individual variability), endogenous plasticities, ontogenetic plasticities) can themselves vary as a function of experiences earlier in life, that is, many types of behavioural plasticity are themselves developmentally plastic. These findings support the assumption that differences among individuals in prior experiences may contribute to individual differences in behavioural plasticities observed at a given age. Several authors have predicted correlations across individuals between different types of behavioural plasticities, i.e. that some individuals will be generally more plastic than others. However, empirical support for most of these predictions, including indirect evidence from studies of relationships between personality traits and plasticities, is currently sparse and equivocal. The final section of this review suggests how an appreciation of the similarities and differences between different types of behavioural plasticities may help theoreticians formulate testable models to explain the evolution of individual differences in behavioural plasticities and the evolutionary and ecological consequences of individual differences in behavioural plasticities.

Two sides of a coin: ecological and chronobiological perspectives of timing in the wild

“…As described above, many species show behavioural and physiological rhythms even under constant conditions (table 1a). These rhythms do not fit the conceptual framework of responses to the environment and are not directly translatable to ecological concepts of phenotypic plasticity (they may be conceptualized as 'endogenous' plasticity; table 1a; [102]). In this context, ecologists can greatly benefit from chronobiological insights, especially if rhythms affect an organism's response to its environment.…”

Fast- and slow-exploring pigeons differ in how they use previously learned rules

“…Then again, how an animal processes new or updates old information may affect that animal's movement through the environment. Exploratory behaviour is one of the most-studied animal personality traits (Reader, 2015;Reale et al, 2007;Stamps, 2015), has been shown to affect fitness (Dingemanse et al, 2004;Smith and Blumstein, 2007), and is heritable (Drent et al, 2003). Several recent empirical studies have examined the relationship between variation in exploration of a novel environment and variation in performance on cognitive tests (see Table 1).…”

“…Several recent empirical studies have examined the relationship between variation in exploration of a novel environment and variation in performance on cognitive tests (see Table 1). The results from this limited, but growing, body of work are inconclusive as to: (1) whether exploration and cognition co-vary and (2) what the nature of the relationship is (reviewed in Stamps, 2015;Griffin et al, 2015). Perhaps the strongest support for the former comes from studies conducted in laboratory mice showing that general learning ability is correlated with exploratory behaviour: mice that score higher in general learning ability (as measured across a suite of tasks) also explore more (Light et al, 2011;Matzel et al, 2006Matzel et al, , 2003 Table 1 for list of cognitive tasks used.…”

Fear is the mother of invention: anuran embryos exposed to predator cues alter life-history traits, post-hatching behaviour, and neuronal activity patterns

“…We exposed embryos to the kairomone of larval predators (dragonfly larvae, Anax imperator) for 9 days and analysed its effects on key life-history traits (time of hatching, developmental stage, hatchling size) and post-hatching anti-predator behaviour before (ontogenetic behavioural plasticity) and after (contextual behavioural plasticity) a postnatal kairomone exposure (see Stamps, 2015, for plasticity terminology). Neurophysiological responses 30 days after hatching were analysed by in vivo whole-cell recording of MC activity from control tadpoles and tadpoles exposed to the kairomone at the embryo stage (hereafter, 'treated tadpoles') before (ontogenetic neuronal plasticity) and after (contextual neuronal plasticity) a postnatal kairomone exposure.…”