Data from: Sex differences in the predictability of risk-taking behaviour

Recent research has found that individuals often vary in how consistently they express their behaviour over time (i.e. behavioural predictability) and suggested that these individual differences may be heritable. However, little is known about the intrinsic factors that drive variation in the predictability of behaviour. Indeed, whether variation in behavioural predictability is sex-specific is not clear. This is important, as behavioural predictability has been associated with vulnerability to predation, suggesting that the predictability of behavioural traits may have key fitness implications. We investigated whether male and female eastern mosquitofish (Gambusia holbrooki) differed in the predictability of their risk-taking behaviour. Specifically, over a total of 954 behavioural trials, we repeatedly measured risk-taking behaviour with three commonly used assays—refuge-use, thigmotaxis, and foraging latency. We predicted that there would be consistent sex differences in both mean-level risk-taking behaviour and behavioural predictability across the assays. We found that risk-taking behaviour was repeatable within each assay, and that some individuals were consistently bolder than others across all three assays. There were also consistent sex differences in mean-level risk-taking behaviour, with males being bolder across all three assays compared to females. In contrast, both the magnitude and direction of sex differences in behavioural predictability were assay specific. Taken together, these results highlight that behavioural predictability may be independent from underlying mean-level behavioural traits and suggest that males and females may differentially adjust the consistency of their risk-taking behaviour in response to subtle changes in environmental conditions.

近期研究发现，个体在行为随时间表达的一致性（即行为可预测性（behavioural predictability））上普遍存在差异，并提出这类个体差异可能具有可遗传性。然而，学界对驱动行为可预测性产生变异的内在因素仍知之甚少。事实上，行为可预测性的变异是否存在性别特异性，目前尚无定论。
这一议题具有重要研究价值：行为可预测性已被证实与被捕食易感性相关，这表明行为性状的可预测性可能对个体适合度存在关键影响。
本研究旨在探究雌雄东部食蚊鱼（Gambusia holbrooki）的冒险行为可预测性是否存在差异。具体而言，研究团队共计开展954次行为测试，通过三项常用实验范式——避难所利用实验（refuge-use）、趋触性实验（thigmotaxis）与觅食潜伏期测定——对其冒险行为进行重复测量。
我们预设，在三项实验范式中，雌雄个体在冒险行为的平均水平与行为可预测性上均会存在稳定的性别差异。
结果显示，每项实验范式内的冒险行为均具有可重复性，且部分个体在三项实验中始终表现得比其他个体更大胆。同时，冒险行为的平均水平确实存在稳定的性别差异：雄性在三项实验中的大胆程度均高于雌性。
与之相反，行为可预测性上的性别差异的幅度与方向均因实验范式而异。
综上，本研究结果表明，行为可预测性可能独立于潜在的平均水平行为性状，并提示雌雄个体可能会根据环境条件的细微变化，差异化调节其冒险行为的一致性。