Abstract Impacts of predators on prey populations are incurred not only through mortality inflicted, but also from how the risk of mortality affects the behaviour, spatial distribution and resource access of potential prey species. This risk is governed by exposure to predators and vulnerability following encounters. Behavioural responses to reduce risks have ramifying consequences for habitat partitioning, regional distributions and local impacts of herbivores on vegetation. These consequences are reviewed for carnivore-ungulate assemblages in African savanna ecosystems. Vigilance serves multiple functions, including locating food and maintaining group cohesion as well as detecting predators. Prey responses depend on whether predators hunt by ambush or pursuit and whether they are mainly diurnally or nocturnally active. Ungulates can lower their vulnerability by restricting time spent foraging at night and avoid places providing cover for lurking carnivores. Risks of predation can have a stronger influence on spatial partitioning among large grazers than distinctions in resource use. Only species above some threshold size have distributions indifferent to tree and grass cover. Observed mortality rates are constrained by recruitment potential. Spatiotemporal variation in risk may regulate populations and limit regional abundance. Herbivores confined to secure habitat may generate local brown-green-black world mosaics. Less common prey species of greatest conservation concern are most susceptible to having their habitat security breached by changes in predation risk. Studies establishing baseline responses of ungulates to the risk of predation need to be augmented by investigations focussed on extreme situations.

中文翻译：

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捕食风险对非洲多食肉动物、多猎物大型哺乳动物组合的影响及其保护意义

摘要 捕食者对猎物种群的影响不仅来自于造成的死亡率，还来自于死亡风险如何影响潜在猎物物种的行为、空间分布和资源获取。这种风险是由暴露于捕食者和遭遇后的脆弱性来控制的。降低风险的行为反应对栖息地划分、区域分布和食草动物对植被的局部影响产生了广泛的影响。审查了非洲热带稀树草原生态系统中食肉动物-有蹄类动物组合的这些后果。警惕具有多种功能，包括定位食物和维持群体凝聚力以及检测捕食者。猎物的反应取决于捕食者是伏击还是追捕，以及它们主要是白天还是夜间活动。有蹄类动物可以通过限制夜间觅食的时间来降低它们的脆弱性，并避免为潜伏的食肉动物提供掩护的地方。与资源利用的差异相比，捕食风险对大型食草动物的空间划分的影响更大。只有高于某个阈值大小的物种的分布与树木和草覆盖无关。观察到的死亡率受到招募潜力的限制。风险的时空变化可能会调节种群并限制区域丰度。被限制在安全栖息地的食草动物可能会产生当地的棕绿色黑色世界马赛克。最受保护的不太常见的猎物物种最容易因捕食风险的变化而破坏其栖息地安全。