Stress hormones, social associations and song learning in zebra finches

Abstract

The use of information provided by others is a common short-cut adopted to inform decision-making. However, instead of indiscriminately copying others, animals are often selective in what, when and whom they copy. How do they decide which ‘social learning strategy’ to use? Previous research indicates that stress hormone exposure in early life may be important: while juvenile zebra finches copied their parents' behaviour when solving novel foraging tasks, those exposed to elevated levels of corticosterone (CORT) during development copied only unrelated adults. Here, we tested whether this switch in social learning strategy generalizes to vocal learning. In zebra finches, juvenile males often copy their father's song; would CORT-treated juveniles in free-flying aviaries switch to copying songs of other males? We found that CORT-treated juveniles copied their father's song less accurately as compared to control juveniles. We hypothesized that this could be due to having weaker social foraging associations with their fathers, and found that sons that spent less time foraging with their fathers produced less similar songs. Our findings are in line with a novel hypothesis linking early-life stress and social learning: early-life CORT exposure may affect social learning indirectly as a result of the way it shapes social affiliations.This article is part of the theme issue ‘Causes and consequences of individual differences in cognitive abilities’.

Measuring and understanding individual differences in cognition

“…For example, developmentally stressed zebra finches, Taeniopygia guttata, exclusively copied unrelated adults whereas control birds copied their parents in learning to solve a novel food puzzle [65,66]. In this special issue, Boogert et al [10] show that these effects also extend to the acquisition of a sexually selected trait: song, which male zebra finches typically learn from their fathers. While overall song copying accuracy did not vary across experimental conditions, developmentally stressed chicks spent more time with non-kin and copied their fathers' songs less accurately.…”

The gut microbiome as a driver of individual variation in cognition and functional behaviour

“…These studies demonstrate that although performance appears equivalent in foraging tasks, individuals may be achieving these outcomes using different strategies mediated by at least two systems that modulate one another, namely the microbiome and the adrenal response. Developmental stress caused either by a disrupted microbiome or by administering glucocorticoids alters with whom individuals associate and from whom they learn (see also [66], this issue). Although recent studies have shown that social networks predict microbial composition in wild primates [12,26], we predict that positions in social networks may also be mediated through microbiome, which in turn influences social transmission of microbes, both commensal and infectious, that may have beneficial [13,67] or detrimental effects [68 -70] on health and cognition.…”

Early-life social environment predicts social network position in wild zebra finches

“…Three recent, and complementary, studies on zebra finches [28,35,36] have aimed to comprehensively characterize how the conditions that individuals face during their development can shape different aspects of later social life. All three studies used the same nestlings, from two captive colonies of zebra finches, Taeniopgygia guttata, that were allocated to two treatments.…”

“…Betweenness reflects how important an individual is as a point of social connection in the overall network [7] and high betweenness can imply an increased tendency of individuals to switch between different groups [28]. The two following studies investigated how early-life stress influenced social learning strategies [35,36]. Evidence suggested that stressed juveniles switched from acquiring novel foraging behaviours from their parents to acquiring them from unrelated adults [36].…”