Data from: Individual versus pseudo-repeatability in behaviour: lessons from translocation experiments in a wild insect

1. Repeatability represents a key parameter in ecological and evolutionary research. Repeatability is underpinned by developmental plasticity and genetic variation but may become biased upwards by repeatable differences in environments to which individuals respond plastically. The extent of upward bias caused by the latter mechanism (causing “pseudo-repeatability”) is important yet rarely investigated in ecological research. 2. We repeatedly assayed a key behaviour (flight initiation distance) affecting longevity in a wild cricket population (Gryllus campestris). We used naturally moving, translocated, and forced-stationary individuals to study bias in repeatability caused by spatial variability in environmental conditions. 3. Our experiments acknowledged that translocations might themselves bias repeatability estimates if animals respond to handling procedures (a necessary component of translocations). Individuals were therefore either (i) repeatedly translocated and assayed, or (ii) assayed at multiple burrows as part of natural movements. This enabled estimation of behavioural variance attributable to individual, burrow, and residual components within each treatment; comparison across treatments addressed whether translocations caused bias. We also calculated repeatability for individuals that forced to be stationary to investigate whether this led to upward biases of repeatability. 4. For adult crickets, individual explained 17.8% versus 17.2%, and burrow 8.7% versus 10.3%, of the behavioural variance in translocated versus natural-movement treatments. Repeatability for forced-stationary adults was 31.1%, thereby demonstrating experimentally that certain study designs bias repeatability upwards. For translocated juveniles, individual explained 10.0% and burrow 6.0% of the variance while in the natural-movement treatment those components could not be separated as juveniles do not switch burrows. Translocations did not lead to detectable biases in behavioural mean or variance. 5. Repeatability was not biased for adults subjected to the natural-movement treatment because individuals were assayed under many different environments, facilitating the separation of individual from burrow effects. Upward bias would have occurred with less optimal sampling schemes: if individuals had been assayed repeatedly at the same burrow. We therefore recommend that translocation experiments are more commonly applied, particularly in stationary species, to ensure the unbiased estimation of repeatability.

1. 可重复性（Repeatability）是生态学与进化研究中的核心参数之一。其基础为发育可塑性（developmental plasticity）与遗传变异（genetic variation），但当个体对环境的可塑性响应存在可重复的差异时，可重复性估计值可能会被高估。由该机制（即引发“伪可重复性（pseudo-repeatability）”）导致的高估程度具有重要研究价值，却在生态学研究中极少被关注。2. 我们针对野生蟋蟀种群（*Gryllus campestris*）中一项影响寿命的核心行为——飞行起始距离（Flight Initiation Distance），开展了重复测定实验。我们利用自然移动、易位以及被迫静止的个体，探究环境条件空间异质性引发的可重复性估计偏差。3. 本实验考虑到，若动物对易位过程中必需的捕捉处理流程产生响应，易位操作本身可能会干扰可重复性估计。因此，我们将实验个体分为两类：(i) 接受重复易位并进行行为测定；(ii) 借助自然移动行为，在多个洞穴中完成行为测定。该设计可在每个处理组中，分离出由个体、洞穴及残差组分导致的行为方差；通过对比不同处理组的结果，可判断易位操作是否引发了估计偏差。此外，我们还对被迫保持静止的个体计算了可重复性，以探究该实验设置是否会导致可重复性被高估。4. 对于成年蟋蟀，易位处理组与自然移动处理组中，个体差异分别解释了17.8%与17.2%的行为方差，洞穴差异则分别解释了8.7%与10.3%的行为方差。被迫静止的成年个体的可重复性达31.1%，这通过实验证实了部分研究设计会高估可重复性。对于易位处理的幼体蟋蟀，个体差异与洞穴差异分别解释了10.0%与6.0%的行为方差；而在自然移动处理组中，由于幼体不会更换洞穴，无法分离这两类方差组分。易位操作未对行为均值或方差产生可检测到的偏差。5. 接受自然移动处理的成年个体的可重复性未出现偏差，这是因为实验在多种不同环境条件下对个体进行了测定，便于分离个体效应与洞穴效应。若采用非最优采样方案——例如仅在同一洞穴中重复测定个体——则会产生高估偏差。因此，我们建议更广泛地采用易位实验，尤其是在栖息相对固定的物种中，以确保可重复性的无偏估计。