School of Natural Sciences, University of Tasmania, Hobart, Tasmania, 7001, Australia.
Australian Research Council Centre for Australian Biodiversity and Heritage, University of Tasmania, Hobart, Tasmania, 7001, Australia.
Ecol Lett. 2020 Apr;23(4):711-721. doi: 10.1111/ele.13473. Epub 2020 Feb 13.
Apex predators can limit the abundance and behaviour of mesopredators, thereby reducing predation on smaller species. We know less about whether native apex predators are effective in suppressing invasive mesopredators, a major global driver of vertebrate extinctions. We use the severe disease-induced decline of an apex predator, the Tasmanian devil, as a natural experiment to test whether devils limit abundance of invasive feral cats and in turn protect smaller native prey. Cat abundance was c. 58% higher where devils had declined, which in turn negatively affected a smaller native prey species. Devils had a stronger limiting effect on cats than on a native mesopredator, suggesting apex predators may have stronger suppressive effects on evolutionarily naive species than coevolved species. Our results highlight how disease in one species can affect the broader ecosystem. We show that apex predators not only regulate native species but can also confer resistance to the impacts of invasive populations. Apex predators could therefore be a powerful but underutilised tool to prevent biodiversity loss.
顶级掠食者可以限制中捕食者的数量和行为，从而减少对较小物种的捕食。我们对于本地顶级掠食者在抑制入侵的中捕食者方面是否有效知之甚少，而后者是全球范围内导致脊椎动物灭绝的主要驱动因素。我们利用一种顶级掠食者——袋獾因严重疾病而数量减少的情况，开展了一项自然实验，以检验袋獾是否会限制入侵的野化猫的数量，从而保护较小的本地猎物。在袋獾数量下降的地方，猫的数量增加了约 58%，这反过来又对一种较小的本地猎物物种产生了负面影响。袋獾对猫的限制作用比对本地中捕食者的限制作用更强，这表明顶级掠食者对进化上较不成熟的物种可能具有比共同进化物种更强的抑制作用。我们的研究结果强调了一个物种的疾病如何影响更广泛的生态系统。我们表明，顶级掠食者不仅可以调节本地物种，还可以为抵御入侵种群的影响提供抵抗力。因此，顶级掠食者可能是一种强大但未被充分利用的工具，可以防止生物多样性丧失。
