Trophic cascades following the disease-induced decline of an apex predator, the Tasmanian Devil

摘要: As apex predators disappear worldwide, there is escalating evidence of their importance in maintaining the integrity and diversity ecosystems they inhabit. The largest extant marsupial carnivore, Tasmanian devil (Sarcophilus harrisii) threatened with extinction from a transmissible cancer, facial tumor disease (DFTD). disease, first observed 1996, has led to apparent population declines excess 95% some areas spread more than 80% range. We analyzed long-term Tasmania-wide data set derived wildlife spotlighting surveys assess effects DFTD-induced decline on populations other mammals examine relative strength top-down bottom-up control mesopredators between 2 regions different environmental conditions. Collection began >10 years before DFTD was observed. A decrease immediate across diseased following arrival, been no indication recovery. Feral cats (Felis catus) increased where present longest, feral cat occurrence significantly negatively associated devils. smallest mesopredator, eastern quoll (Dasyurus viverrinus), declined rapidly arrival. This result suggests species indirectly protected by devils through suppression larger predators. Rainfall deficiency also significant predictor decline. Environmental variables determined regulation mesopredators. In landscapes low rainfall relatively higher proportions agriculture human settlement, forces were dampened had most effect For herbivore prey species, differences after but undetected factors greater effects. unique opportunity changes over extensive temporal spatial scales predator loss further demonstrated role structuring productivity determining control.