Feral cats are better killers in open habitats, revealed by animal-borne video

One of the key gaps in understanding the impacts of predation by small mammalian predators on prey is how habitat structure affects the hunting success of small predators, such as feral cats. These effects are poorly understood due to the difficulty of observing actual hunting behaviours. We attached collar-mounted video cameras to feral cats living in a tropical savanna environment in northern Australia, and measured variation in hunting success among different microhabitats (open areas, dense grass and complex rocks). From 89 hours of footage, we recorded 101 hunting events, of which 32 were successful. Of these kills, 28% were not eaten. Hunting success was highly dependent on microhabitat structure surrounding prey, increasing from 17% in habitats with dense grass or complex rocks to 70% in open areas. This research shows that habitat structure has a profound influence on the impacts of small predators on their prey. This has broad implications for management of vegetation and disturbance processes (like fire and grazing) in areas where feral cats threaten native fauna. Maintaining complex vegetation cover can reduce predation rates of small prey species from feral cat predation.

当前学界在解析小型哺乳类捕食者对猎物的捕食效应时，尚存一项关键认知空白：即栖息地结构如何影响野化猫（feral cats）这类小型捕食者的捕猎成功率。由于难以直接观测真实捕猎行为，学界对这类影响的认知仍较为匮乏。研究团队为栖息于澳大利亚北部热带稀树草原环境中的野化猫佩戴了项圈式摄像机，并针对开阔区域、密生草丛与复杂岩区等不同微生境下的捕猎成功率差异开展了量化分析。在总计89小时的拍摄素材中，共记录到101次捕猎行为，其中32次获得成功；在这些成功捕杀的猎物中，有28%未被野化猫取食。研究结果显示，捕猎成功率高度依赖猎物周边的微生境结构：从密生草丛或复杂岩区生境中的17%，提升至开阔区域的70%。本研究证实，栖息地结构对小型捕食者的猎物捕食效应具有极为显著的影响，这一结论对于野化猫威胁本土野生动物区域的植被管理与干扰过程（如火灾与放牧）具有广泛的指导意义。维持复杂的植被覆盖度，可降低小型猎物物种的被捕食率。