Amur tiger urine increases small -bodied mesopred

Apex predators exert dual effects on mesopredators, including both suppression through lethal encounters and fear, as well as facilitation through providing food via prey remains. While large-scale studies on how apex predators influence mesopredator distributions are abundant, research on how apex predators affect mesopredators at the fine scale—particularly their specific behaviors—remains limited.
Using Amur tiger urine as an apex predator cue and captive bird eggs—which served as a food source for mesopredators with minimal odor interference—we evaluated the effects of this apex predator scent on the foraging behavior of mesopredators in northeastern China. Our results demonstrate that tiger urine attracted small-bodied mesopredators, increasing their visitation speed and accelerating nest predation. Asian badgers in particular perceived tiger urine as a food resource cue, stimulating their exploration and squat-marking behavior improving egg detection and predation.
This study focuses on the behavioral impacts of tiger urine on small-bodied mesopredators, revealing how top predator signals shape the foraging behavior of small-bodied mesopredators at the local scale. Specifically, top predators may exert greater attractive effects than fear effects on mesopredators with significantly smaller body sizes—a finding that deviates from the traditional paradigm that "top predators generally suppress mesopredators". Ultimately, this study deepens our understanding of the complex interactions between top predators and mesopredators, and provides references for ecological regulation (e.g., regulation of lower-trophic-level species) in future species conservation efforts.

顶级捕食者(apex predator)对中级捕食者(mesopredator)具有双重调控效应：一方面通过致死遭遇与恐惧产生抑制作用，另一方面通过遗留猎物提供食物来源发挥促进作用。现有针对顶级捕食者如何影响中级捕食者分布的大尺度研究已较为丰富，但聚焦于细尺度（尤其是其具体行为）上顶级捕食者对中级捕食者影响的研究仍较为匮乏。
本研究以东北虎(Amur tiger)尿液作为顶级捕食者信号线索，同时选用气味干扰极小的笼养禽蛋作为中级捕食者的食物来源，在中国东北地区开展实验，评估该顶级捕食者气味对中级捕食者觅食行为的影响。研究结果显示，东北虎尿液可吸引小型中级捕食者，提升其造访速率并加快巢穴捕食进程。其中，亚洲狗獾尤其将东北虎尿液视为食物资源线索，进而激发其探索行为与蹲伏标记行为，增强了对禽蛋的探测与捕食效率。
本研究聚焦东北虎尿液对小型中级捕食者的行为影响，揭示了局部尺度下顶级捕食者信号如何塑造小型中级捕食者的觅食行为。具体而言，相较于体型显著更小的中级捕食者，顶级捕食者对其产生的吸引效应可能强于恐惧抑制效应——这一发现与「顶级捕食者通常会抑制中级捕食者」的传统范式相悖。本研究最终深化了我们对顶级捕食者与中级捕食者间复杂互作关系的认知，并为未来物种保护工作中的生态调控（例如低营养级物种调控）提供了参考依据。