Data from: Mesopredator suppression by an apex predator alleviates the risk of predation perceived by small prey

Predators can impact their prey via consumptive effects that occur through direct killing and via non-consumptive effects that arise when the behaviour and phenotypes of prey shift in response to the risk of predation. Although predators’ consumptive effects can have cascading population level-effects on species at lower trophic levels there is less evidence that predators’ non-consumptive effects propagate through ecosystems. Here we provide evidence that suppression of abundance and activity of a mesopredator, the feral cat, by an apex predator, the dingo, has positive effects on both abundance and foraging efficiency of a desert rodent. Then by manipulating predators’ access to food patches we further the idea that apex predators provide small prey with refuge from predation by showing that rodents increased their habitat breadth and use of “risky” food patches where an apex predator was common but mesopredators rare. Our study suggests that apex predators’ suppressive effects on mesopredators extend to alleviate both mesopredators’ consumptive and non-consumptive effects on prey.

捕食者可通过两种途径对猎物产生影响：一是通过直接杀戮产生的消耗效应（consumptive effects），二是当猎物的行为与表型（phenotypes）因应对捕食风险而发生改变时产生的非消耗效应（non-consumptive effects）。尽管捕食者的消耗效应可对低营养级物种产生级联种群效应，但目前支撑捕食者非消耗效应沿生态系统传递的证据仍较为匮乏。本研究提供证据表明，顶级捕食者（apex predator）澳洲野犬（dingo）对中型捕食者（mesopredator）野化猫（feral cat）的种群数量与活动行为的抑制作用，可对荒漠啮齿类的种群数量与觅食效率产生积极影响。随后，本研究通过操控捕食者对食物斑块的可及性，进一步验证了“顶级捕食者可为小型猎物提供捕食庇护”这一观点——研究发现，在顶级捕食者常见而中型捕食者稀少的区域，啮齿类的生境广度与对“高风险”食物斑块的利用程度均有所提升。本研究结果表明，顶级捕食者对中型捕食者的抑制作用，可进一步缓解中型捕食者对猎物产生的消耗效应与非消耗效应。