Dynamic shifts in predator diel activity patterns across landscapes and threat levels

Understanding the constraints dominant predators impose on subordinate species is important for predicting ecosystem dynamics and anticipating outcomes of predator management. Subordinate predators may avoid dominant predators in time or space, making it difficult to quantify antipredator behaviours unless joint spatiotemporal analyses are used. Here, we tested whether an invasive dominant predator (red fox Vulpes vulpes) alters the spatiotemporal activity of an invasive subordinate predator (feral cat Felis catus). We collated records of both species from 3,667 camera-traps deployed experimentally across two regions of south-eastern Australia with simplified predator guilds. Foxes were poison-baited in some landscapes within each region. We used generalised additive models to quantify changes in predator spatiotemporal activity across geographic space, vegetation types, human footprint and (artificially manipulated) gradients of dominant predator activity. Foxes and cats had similar di...明确顶级捕食者（dominant predator）对从属捕食物种施加的生存制约，对于预测生态系统动态及预判捕食者管理措施的实施效果具有重要意义。从属捕食者通常会在时间或空间维度上规避顶级捕食者，这使得量化其反捕食行为（antipredator behaviour）极具挑战，除非采用联合时空分析方法。本研究旨在探究入侵性顶级捕食者赤狐（Vulpes vulpes）是否会改变入侵性从属捕食者野化猫（Felis catus）的时空活动节律。我们从澳大利亚东南部两个捕食者类群结构简化的区域中，整理了3667台实验布设的相机陷阱（camera-trap）所记录的两种物种的观测数据。两个区域内的部分生境区域均投放了针对赤狐的毒饵。本研究采用广义加性模型（Generalized Additive Models），量化了捕食者时空活动在地理空间、植被类型、人类活动足迹以及（人工调控的）顶级捕食者活动梯度上的变化。赤狐与野化猫具有相似的昼间……