Predation fear is a unifying theme across vertebrate taxa. Here, we explored how the frequency and duration of predation risk affects postrisk fear behavior in Trinidadian guppies. We first exposed individuals to visual cues of potential predators for 3 days, either frequently (6×/day) or infrequently (1×/day). Each exposure lasted for either a relatively brief (5 min) or long (30 min) duration, whereas a control group consisted of no risk exposures. One day later, we quantified guppy behavior. All background risk treatments induced a fear response toward a novel odor (i.e., neophobia), and individuals previously exposed to frequent bouts of brief risk showed elevated baseline fear. Although neophobic responses were initially similar across risk treatments (1 day later), retention of this response differed. After 8 days, only individuals previously exposed to brief bouts of risk (both frequent and infrequent) maintained neophobic responses, whereas their initially higher level of baseline fear remained elevated but was no longer significantly different from the control. These results increase our understanding of temporal factors that affect the intensity and retention of fear that persists after risk exposure, which may have applications across vertebrates in relation to problems with fearful phenotypes.

中文翻译：

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特立尼达孔雀鱼的暂时变捕食风险和恐惧保留

掠夺恐惧是整个脊椎动物类群的统一主题。在这里，我们探讨了捕食风险的频率和持续时间如何影响特立尼达孔雀鱼的后恐惧行为。我们首先将个体暴露于潜在掠食者的视觉线索持续3天（频繁（6x /天）或不频繁（1x /天））。每次暴露持续相对较短的时间（5分钟）或较长的时间（30分钟），而对照组则没有风险暴露。一天后，我们量化了孔雀鱼的行为。所有本底风险治疗均引起对新气味（即恐惧症）的恐惧反应，以前曾频繁遭受短暂风险发作的个体表现出基线恐惧。尽管在各种风险治疗方法（1天后）中，新恐惧症的反应最初相似，但这种反应的保留时间却有所不同。8天后 只有以前曾短暂发作过风险（频繁和不频繁）的个体维持新恐惧症反应，而他们最初较高的基线恐惧水平仍然升高，但不再与对照组有显着差异。这些结果增加了我们对影响风险暴露后持续存在的恐惧的强度和保持力的时间因素的理解，这些时间因素可能在脊椎动物中与恐惧表型相关。