Continent wide effects of dingoes on Australian ecosystems
The importance of top-order predators in maintaining ecosystem function has been demonstrated in many marine and terrestrial systems. Top-order predators often have strong effects on biological diversity by limiting populations and reducing impacts of their prey and/or subordinate competitors. Consequently, restoring and maintaining populations of top predators has been identified as a critical imperative for the conservation of biodiversity and ecosystem services. Here, we provide evidence that multiple cascade pathways induced by lethal control of an apex predator, the dingo, drive unintended shifts in ecosystem structure. We compared mammal assemblages and understorey structure at 24 sites across different ecosystems in Australia. Each site comprised an area where dingoes were poisoned and an area without control.
The effects of dingo control on mammals scaled with body size. Activity of herbivorous macropods, arboreal mammals and mesopredators, the red fox and cat were greater, but understorey vegetation sparser and abundances of small mammals lower, where dingoes were controlled. Our study suggests that apex predators’ suppressive effects on herbivores and mesopredators occur simultaneously and should be considered in tandem in order to appreciate the extent of apex predators’ indirect effects.