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Ecosystem impacts following disease-induced top predator decline: The Tasmanian devil and DFTD - Wildlife Society Conference

Wildlife Society’s 18th Annual Conference

Waikoloa, Hawaii

November 5-10, 2011

ORAL PRESENTATION

Abstract

Tracey Hollings1
Greg Hocking 2
Menna Jones1
Nick Mooney 2
Hamish McCallum3

1 University of Tasmania, Hobart, TAS, Australia
2 Department of Primary Industries and Water, Hobart, TAS, Australia
3 Griffith University, Brisbane, Australia


Apex predators are increasingly recognised as important to the integrity of ecosystems and their loss can result in wide-ranging effects. The largest extant marsupial carnivore, the Tasmanian devil, Sarcophilus harrisi, is threatened with extinction from an infectious cancer, devil facial tumor disease (DFTD). The disease, first observed in 1996, has led to population declines in excess of 95% in some areas and has spread to more than 50% of the devil’s range. DFTD-driven decline of the devil provides us with a rare opportunity to study the role of carnivores in the landscape.

We analysed a long-term Tasmania-wide spotlighting dataset pre-dating DFTD by more than a decade, to assess the impacts of DFTD arrival and subsequent devil decline on other fauna. Feral cats increased in long-term DFTD regions, however bottom up forces of prey availability may be important in lower productivity regions. The eastern quoll, a smaller mesopredator, showed dramatic declines corresponding to DFTD arrival. Herbivorous prey species show some evidence of population differences before and after DFTD arrival, but other environmental influences were more important. Despite the limitations of this dataset, such studies are imperative to develop management priorities to maintain ecosystem function in the absence of apex predators.

BIOBUZZ ISSUE FIFTEEN, DECEMBER 2011