Past threatening experiences, such as exposure to a predator or a capture event, can influence an animal's future behaviour, with profound consequences on its survival and ultimate fitness. We hypothesize that an animal's physiological stress response phenotype modulates the influence of past experiences on future behaviour in the Florida scrub-jay, Aphelocoma coerulescens, a species that exhibits individual physiological stress response phenotypes that are repeatable across a life span. We subjected young, trap-capture-naive Florida scrub-jays to a standardized capture and restraint protocol to quantify stress-induced levels of circulating glucocorticoids. Twenty-four hours later, we assessed their response to a novel object and compared this measure of neophobia to age-matched individuals that had never been captured in a trap. We predicted that individuals trapped prior to novel object trials would be more neophobic than noncaptured controls. Furthermore, we predicted that scrub-jays with high glucocorticoid responses would be the most neophobic. Indeed, previously captured individuals had longer latencies to approach and enter a novel ring compared to controls. Past trap experience interacted with a bird's physiological phenotype to influence their neophobic behaviour. Contrary to our predictions, trapped birds with a low glucocorticoid response phenotype were more neophobic compared to low response controls, whereas trapped individuals with a high response phenotype where less neophobic compared to high response controls. Our results demonstrate that experience can affect individuals differently depending on their physiological phenotype. This novel finding highlights the need to consider how differential responses to invasive and captive protocols may confound results of behavioural studies involving free-living subjects.

中文翻译：

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过去的威胁经历与未来的恐新行为之间的联系取决于生理应激反应

过去的威胁经历，例如暴露于捕食者或捕获事件，会影响动物未来的行为，对其生存和最终健康产生深远的影响。我们假设动物的生理应激反应表型会调节过去的经历对佛罗里达灌木丛鸦的未来行为的影响，Aphelocoma coerulescens，一种表现出在整个生命周期中可重复的个体生理应激反应表型的物种。我们让年轻的、没有捕获捕获的佛罗里达小鸟接受标准化的捕获和约束协议，以量化压力引起的循环糖皮质激素水平。24 小时后，我们评估了他们对新物体的反应，并将这种新恐惧症的测量与从未被陷阱捕获的年龄匹配的个体进行了比较。我们预测，在新物体试验之前被困的个体会比未被俘获的对照组更怕新。此外，我们预测具有高糖皮质激素反应的灌木丛鸦将是最怕新的。事实上，与对照组相比，先前捕获的个体接近和进入新环的等待时间更长。过去的陷阱经验与鸟类的生理表型相互作用，以影响它们的恐新行为。与我们的预测相反，与低反应对照相比，具有低糖皮质激素反应表型的被困鸟类更怕新，而具有高反应表型的被困个体与高反应对照相比，新恐惧更少。我们的结果表明，经验可以根据他们的生理表型对个人产生不同的影响。