Risk-taking behaviours that are optimal in one context (predators absent) may be suboptimal in a different context (predators present), suggesting that individuals with ‘bold’ behaviours will experience increased predation risk. Yet, in some instances, bold individuals experience lower predation. Thus, there is not always a direct trade-off between boldness and predation risk. To better understand the relationship between boldness and predation risk, suboptimal behaviours must be viewed within the context of an organism's entire integrated antipredator strategy. Using freshwater snails exposed to a predator cue, we examined whether quickly re-emerging from the shell was a repeatable, carryover behaviour that was tied to behavioural and morphological antipredator traits. Slow-emerging snails invested in morphological shell defence and remained in the predator environment, whereas quick-emerging snails consistently avoided the predator environment and did not invest in shell defences. Therefore, slow-emerging snails used a sit-and-wait antipredator strategy by relying on their shells for protection and were less likely to avoid the predator environment; conversely, quick-emerging snails used an avoidance (or dispersal) strategy by consistently associating with the water's surface and investing less in shell defences. A path analysis of these antipredator traits indicates that the carryover effect of bold behaviour may be an important factor that mediates complementary behavioural and morphological traits that reduce predation risks. This study supports the ‘behavioural character’ hypothesis, which suggests that boldness is a latent variable upon which selection can act and thereby shape a variety of quasi-independent traits (e.g. antipredator traits). According to this perspective, selection is not acting on a single antipredator behavioural trait in isolation, but rather on an integrated antipredator strategy that is facilitated by individual differences in carryover risk-taking behaviour.

中文翻译：

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“行为特征”假设的证据：大胆计划是否与反捕食者策略不同？

在一种情况下（没有捕食者）最佳的冒险行为在不同的情况下（有捕食者存在）可能是次优的，这表明具有“大胆”行为的个体将经历增加的捕食风险。然而，在某些情况下，大胆的个体经历较少的捕食。因此，在大胆和捕食风险之间并不总是有直接的权衡。为了更好地理解大胆和捕食风险之间的关系，必须在生物体的整个综合抗捕食者策略的背景下看待次优行为。使用暴露于捕食者线索的淡水蜗牛，我们检查了从壳中快速重新出现是否是一种可重复的、与反捕食者的行为和形态特征相关的遗留行为。缓慢出现的蜗牛投资于形态外壳防御并留在捕食者环境中，而快速出现的蜗牛始终避开捕食者环境并且不投资于外壳防御。因此，缓慢出现的蜗牛通过依靠它们的外壳保护而使用坐等反捕食者策略，并且不太可能避开捕食者环境；相反，快速出现的蜗牛通过始终与水面联系并减少对贝壳防御的投资来使用回避（或分散）策略。对这些反捕食者特征的路径分析表明，大胆行为的结转效应可能是介导减少捕食风险的互补行为和形态特征的重要因素。这项研究支持“行为特征”假设，这表明大胆是一个潜在的变量，选择可以根据它起作用，从而塑造各种准独立特征（例如反捕食者特征）。根据这个观点，选择不是孤立地作用于单一的反捕食者行为特征，而是作用于一个综合的反捕食者策略，这种策略是由遗留风险行为的个体差异促进的。