Cats and dogs: A mesopredator navigating risk and reward provisioned by an apex predator

Successfully perceiving risk and reward is fundamental to the fitness of an animal, and can be achieved through a variety of perception tactics. For example, mesopredators may ‘directly’ perceive risk by visually observing apex predators, or may ‘indirectly’ perceive risk by observing habitats used by predators. Direct assessments should more accurately characterize the arrangement of risk and reward; however, indirect assessments are used more frequently in studies concerning the response of GPS-marked animals to spatiotemporally variable sources of risk and reward. We investigated the response of a mesopredator to the presence of risk and reward created by an apex predator, where risk and reward likely vary in relative perceptibility (i.e., degree of being perceptible). First, we tested whether coyotes (Canis latrans) use direct or indirect assessments to navigate the presence of mountain lions (Puma concolor; risk) and kills made by mountain lions (reward) in an area where coyotes we...成功感知风险与收益是动物生存适合度的核心基础，该能力可通过多种感知策略实现。例如，中型捕食者可通过直接视觉观测顶级捕食者来‘直接’感知风险，也可通过观测顶级捕食者所利用的栖息地来‘间接’感知风险。直接评估本应更精准地刻画风险与收益的分布格局；然而，现有针对佩戴全球定位系统（GPS）追踪标记的动物对时空动态变化的风险与收益源响应的相关研究中，间接评估的应用更为普遍。本研究聚焦于中型捕食者对顶级捕食者所产生的风险与收益的响应，其中风险与收益的相对可感知度（即被感知的难易程度）可能存在差异。首先，我们测试了郊狼（Canis latrans）是否会采用直接或间接评估方式，以应对某区域内美洲狮（Puma concolor，代表风险）及其捕猎遗留的猎物残骸（代表收益）的存在，该区域内郊狼的