Department of Biomedical Sciences, WCVM, University of Saskatchewan, Saskatoon, SK S7W 5B4, Canada.
Anim Cogn. 2013 Jul;16(4):667-76. doi: 10.1007/s10071-013-0602-6. Epub 2013 Feb 7.
Due to the high variability in predation risk through space and time, prey have to continuously update information about the risk level posed by predators. Despite numerous studies focusing on temporal risk assessment, we know very little about how individuals deal with information regarding changes in risk level of a given predator through time. In this study, we conditioned tadpoles to recognize a predator as a high or low risk twice 2 weeks apart, in a 2 × 2 design. We tested the responses of the tadpoles 1 and 11 days after each conditioning event. Prey showed responses to the predator 1 day after the first conditioning, but the low-risk group failed to respond to the predator after 11 days. However, we found that information learned during the first conditioning affected the response to the predator after the second conditioning, indicating that prey do not 'forget' old information, but simply ignore it. Moreover, tadpoles were able to assess their change in vulnerability over the 2-week period and further extrapolate the risk level of the predator through time to display adaptive threat-sensitive antipredator responses. Our study highlights the complex decision-making that prey use to assess temporal fluctuation in predation risk.
由于捕食风险在空间和时间上存在高度可变性，猎物必须不断更新有关捕食者风险水平的信息。尽管有许多研究专注于时间风险评估，但我们对于个体如何处理有关给定捕食者的风险水平随时间变化的信息知之甚少。在这项研究中，我们采用 2×2 设计，在两周的时间间隔内两次使蝌蚪适应识别一种高风险或低风险的捕食者。我们在每次适应后 1 天和 11 天测试了蝌蚪的反应。在第一次适应后的 1 天，猎物对捕食者做出了反应，但低风险组在 11 天后未能对捕食者做出反应。然而，我们发现，第一次适应过程中获得的信息会影响第二次适应后的捕食者反应，表明猎物不会“忘记”旧信息，只是简单地忽略它。此外，蝌蚪能够在两周的时间内评估自己的脆弱性变化，并通过时间进一步推断捕食者的风险水平，从而表现出适应性的威胁敏感的防御反应。我们的研究强调了猎物用来评估捕食风险随时间波动的复杂决策过程。
