Perception of predation risk under unpredictable conditions: chemosensory cues and the indirect effects of predation.

猎物不断面临着捕食者回避和其他适应性相关活动，如觅食，领土防御和求偶的相互冲突的需求。平衡这些权衡的关键是可靠地评估当地捕食威胁的能力。然而，捕食风险很少在空间和时间上是可预测的，增加了与风险评估相关的成本。不可预测的捕食的影响和由此产生的风险的不确定性现在才开始受到审查。越来越多的研究认为，当地条件的不确定性（即觅食机会;捕食威胁）将增加获得的公共信息的价值（即作为风险评估线索的可靠性），这种信息应使猎物能够更确定地预测风险。然而，学习识别新线索作为公共信息来源本身是昂贵的（即在最初遇到新威胁时有被捕食的风险）。最近，我们已经证明，在不可预测的风险条件下，猎物可能会受益于响应任何新的线索作为一种风险（neophobia）。通过这样做，猎物可以减少最初遭遇的成本）。在这里，我们测试的假设，响应新的捕食者线索是一种适应性反应的不可预测性，在当地的捕食威胁和新恐惧症允许猎物，以减少其整体成本与平衡捕食者避免权衡。我们还建议应用我们的neophobia模型来检验这一假设，即诱导neophobic捕食者回避可以提高放养后的生存孵化饲养鲑鱼。每年，数以百万计的孵化场饲养的幼鲑被放养到自然水道中，作为重建或维持自然种群的持续努力的一部分。然而，缺乏学习的机会，在孵化设置和减少表型方差的综合影响，导致穷人放养后的生存。我们将测试将诱导性新恐惧症和生态相关学习应用于当前生活技能培训计划的可行性，以加强再引入计划。结合起来，这些结果将推进我们的猎物种群之间的风险评估的知识，并可能提供一个有价值的工具，以加强鲑鱼保护计划。

Prey are continually faced with the conflicting demands of predator avoidance and other fitness related activities such as foraging, territorial defence and courtship. Key to balancing these trade-offs is the ability to reliably assess local predation threats. However, predation risk is seldom spatially and temporally predictable, increasing the costs associated with risk assessment. The effects of unpredictable predation and the resulting uncertainty of risk are only now beginning to be examined. A growing body of research argues that uncertainty about local conditions (i.e. foraging opportunities; predation threats) will increase the value (i.e. reliability as a risk assessment cue) of acquired public information and that such information should allow prey to predict risk with greater certainty. However, learning to recognize novel cues as sources of public information is in itself costly (i.e. risk of predation during initial encounters with novel threats). Recently, we have demonstrated that under unpredictable risk conditions, prey may benefit from responding any novel cues as a risk (neophobia). By doing so, prey could reduce the cost of the initial encounter). Here, we test the hypothesis that responding to novel predator cues is an adaptive response to unpredictability in local predation threats and that neophobia allows prey to reduce their overall costs associated with balancing predator avoidance trade-offs. We also propose to apply our neophobia model to test the hypothesis that inducible neophobic predator avoidance can enhance the post-stocking survival of hatchery-reared salmonids. Each year, millions of hatchery-reared juvenile salmonids are stocked into natural waterways as part of ongoing efforts to re-establish or maintain natural populations. However, the combined effects of lack of learning opportunities within a hatchery setting and reduced phenotypic variance leads to poor post-stocking survival. We will test the feasibility of applying inducible neophobia and ecologically relevant learning to current life-skills training programs in an effort to enhance reintroduction programs. Combined, these results will advance our knowledge of risk assessment among prey populations and potentially provide a valuable tool to enhance salmon conservation programs.