Nesting mortality in birds is caused primarily by predation. The ability to use different predator cues to assess the level of predation risk could be essential to minimize the predation risk during the breeding period. Previous studies show that birds modified their parental behavior when they detected chemical or visual cues of predators in the surrounding of the nest. However, according to the threat sensitivity hypothesis, birds may use more than one predator cue in order to accurately assess the level of predation risk. In this assessment, the behavior of predators can provide important information to evaluate the motivation of the predator to launch an attack. However, there are no studies that examined the importance of chemical, visual and behavioral cues of predators on the antipredatory behavior of birds. We examined the antipredatory behavior of blue tit Cyanistes caeruleus parents when they were exposed to live predators or stuffed models of predators that also had predator chemical cues. Blue tits were able to detect the behavioral cues of predators and exhibited greater antipredatory behaviors when exposed to a live predator than to a stuffed model with chemical cues. The results suggest that birds use the chemical, visual and behavioral cues of the predators to assess the level of predation risk and adjust their antipredatory behavior accordingly.

中文翻译：

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捕食者的化学，视觉和行为线索对鸟类反捕食行为的重要性

鸟类的筑巢死亡率主要是由捕食引起的。使用不同的捕食者线索评估捕食风险水平的能力对于将繁殖期间的捕食风险降至最低至关重要。先前的研究表明，当鸟类在巢周围发现捕食者的化学或视觉线索时，它们会改变其父母的行为。但是，根据威胁敏感性假设，鸟类可能会使用一种以上的捕食者提示，以便准确评估捕食风险的水平。在此评估中，掠食者的行为可以提供重要信息，以评估掠食者发动攻击的动机。但是，没有研究检查掠食者的化学，视觉和行为暗示对鸟类的反掠夺行为的重要性。蓝藻蓝斑双亲，当他们接触活的捕食者或填充了捕食者模型的捕食者也有捕食者化学线索时，就将其作为父母。蓝雀能够检测到捕食者的行为线索，并且在暴露于活泼的捕食者中比在化学线索下的填充模型中表现出更大的抗掠夺行为。结果表明，鸟类利用掠食者的化学，视觉和行为线索来评估掠食风险的水平并相应地调整其反掠食行为。