Data from: Is behavioural plasticity consistent across different environmental gradients and through time?

Despite accumulating evidence for individual variation in behavioural plasticity, there is currently little understanding of the causes and consequences of this variation. An outstanding question is whether individual reaction norm (RN) slopes are consistent across different environmental variables – that is, whether an individual that is highly responsive to one environmental variable will be equally responsive to a second variable. Another important and related question is whether RNs are themselves consistently expressed through time or whether they are simply state dependent. Here, we quantified individual activity rates of zebrafish in response to independent manipulations of temperature and food availability that were repeated in discrete ‘bursts’ of sampling through time. Individuals that were thermally responsive were not also more responsive to food deprivation, but they were less predictable? did exhibit greater unexplained variation. Individual RN slopes were consistent (repeatable) over time for both temperature (Rslope = 0.92) and food deprivation responses (Rslope = 0.4), as were mean activity rates in the standard environment (Rintercept = 0.83). Despite the high potential lability of behaviour, we have demonstrated consistency of behavioural RN components and identified potential energetic constraints leading to high consistency of thermal RNs and low consistency of food deprivation RNs.尽管已有大量研究证实行为可塑性（behavioural plasticity）存在个体差异，但目前学界对该差异的成因与后果仍知之甚少。一个悬而未决的核心问题是：个体的反应规范（reaction norm, RN）斜率是否在不同环境变量间保持一致——即对某一环境变量具有高响应性的个体，是否对另一环境变量同样具备高响应性。另一个与之密切相关的重要问题是，反应规范本身是否会随时间稳定表达，抑或仅受个体当前状态的调控。本研究对斑马鱼（zebrafish）的个体活动速率进行了量化分析：通过独立操控温度与食物可获得性两个环境因子，并在不同时间节点以离散采样批次的形式重复开展采样工作。结果表明，对温度具有响应性的个体，并不会对食物剥夺表现出更强的响应性，但其活动的可预测性更低——即存在更高的未解释变异。两类响应的个体RN斜率均随时间保持稳定（可重复）：温度响应的斜率重复度Rslope=0.92，食物剥夺响应的斜率重复度Rslope=0.4；标准环境下的平均活动速率同样具有较高的重复性（截距重复度Rintercept=0.83）。尽管行为具有极高的潜在易变性，本研究仍证实了行为RN组分的稳定性，并揭示了潜在的能量约束机制：该机制使得温度响应RN具有高稳定性，而食物剥夺响应RN的稳定性较低。