Chemosensory assessment of local predation threats in aquatic vertebrates

被捕食动物经常面临着相互冲突的需求，即发现和避免捕食者以及一系列其他与健康相关的行为活动，包括觅食，交配和领土防御。威胁敏感的捕食者回避假说预测，猎物能够调整的antipredator反应的强度成比例的程度感知的威胁应该更好地装备，以平衡这些权衡。这些模型假设猎物可以可靠地评估当地的捕食风险，但令人惊讶的是，我们对猎物如何感知风险或形成这些权衡的因素知之甚少。在我的实验室最近的研究集中在使用化学感觉的线索作为可靠的指标的风险，为一些猎物的鱼类和这些线索的功能，在威胁敏感的决策。在一系列的实验室和实地研究中，我将研究猎物如何整合多种信息源（即，化学感觉和视觉线索），以及环境因素，如资源竞争，群体大小和栖息地的复杂性如何影响威胁敏感的决定。我还将研究捕食风险的变化在短期（几天或几周），长期（整个生长季节）或进化（多代）的持续时间在形成威胁敏感的权衡的时间尺度上的作用。威胁敏感度模型预测，个体应该能够改变自己的行为，以补偿与避免捕食者相关的成本，尽管这在自然条件下基本上还没有经过测试。我将进行长期的实地研究来调查这一假设。最后，大量的最新研究表明，人为污染物，如酸雨，损害的猎物鱼类化学评估当地捕食风险的能力。 它仍然是未知的，如果猎物可以弥补化学感觉输入的损失，无论是改变他们的行为模式或增加他们对其他非化学输入的依赖。 通过提高我们的猎物如何评估和应对当地捕食威胁的威胁敏感的方式的理解，我们希望提高环境评估和管理计划和渔业资源增加的努力的生态有效性。

Prey animals are often faced with the conflicting demands of the detection and avoidance of predators and a suite of other fitness related behavioural activities, including foraging, mating and territorial defence. The threat-sensitive predator avoidance hypothesis predicts that prey capable of adjusting the intensity of the antipredator response proportional to the degree of perceived threat should be better equipped to balance these trade-offs. Such models assume that prey can reliably assess local predation risk, yet surprisingly little is known about how prey perceive risk or about the factors that shape these trade-offs. Recent studies in my laboratory have focused on the use chemosensory cues as reliable indicators of risk for a number of prey fishes and how these cues function in threat-sensitive decision-making. In a series of laboratory and field studies, I will examine how prey integrate multiple information sources (i.e., chemosensory and visual cues) and how environmental factors such as resource competition, group size and habitat complexity influence threat-sensitive decisions. I will also examine the role of variability in predation risk over time scales ranging over short-term (days or weeks), long-term (entire growing seasons) or evolutionary (multigenerational) durations plays in the shaping of threat-sensitive trade-offs. Threat-sensitivity models predict that individuals should be able to alter their behaviour in order to compensate for the costs associated with predator avoidance, though this remains largely untested under natural conditions. I will conduct long-term field studies to investigate this hypothesis. Finally, a great deal of recent research demonstrates that anthropogenic pollutants, such as acid precipitation, impair the ability of prey fishes to chemically assess local predation risks. It remains unknown if prey can compensate for the loss of chemosensory inputs by either altering their behaviour patterns or increasing their reliance on other, non-chemical inputs. By improving our understanding of how prey assess and respond to local predation threats in a threat-sensitive fashion, we hope to enhance the ecological validity of environmental assessment and management programs and fisheries stock enhancement efforts.