| Title: | Top carnivore decline has cascading effects on scavengers and carrion persistence |
| Author(s): | Cunningham CX; Johnson CN; Barmuta LA; Hollings T; Woehler EJ; Jones ME; |
| Address: | "School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia calum.cunningham@utas.edu.au calumcunningham11@gmail.com. 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. Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria 3084, Australia. Centre of Excellence for Biosecurity Risk Analysis, School of Biosciences, University of Melbourne, Parkville, Victoria 3010, Australia. Birdlife Tasmania, GPO Box 68, Hobart, Tasmania, Australia" |
| ISSN/ISBN: | 1471-2954 (Electronic) 0962-8452 (Print) 0962-8452 (Linking) |
| Abstract: | "Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania's top carnivore, the Tasmanian devil (Sarcophilus harrisii), has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native mesopredators was best predicted by competition for carrion, whereas consumption by the invasive mesopredator, the feral cat (Felis catus), was better predicted by the landscape-level abundance of devils, suggesting a relaxed landscape of fear where devils are suppressed. Reduced discovery of carcasses by devils was balanced by the increased discovery by mesopredators. Nonetheless, carcasses persisted approximately 2.6-fold longer where devils have declined, highlighting their importance for rapid carrion removal. The major beneficiary of increased carrion availability was the forest raven (Corvus tasmanicus). Population trends of ravens increased 2.2-fold from 1998 to 2017, the period of devil decline, but this increase occurred Tasmania-wide, making the cause unclear. This case study provides a little-studied potential mechanism for mesopredator release, with broad relevance to the vast areas of the world that have suffered carnivore declines" |
| Keywords: | Animals Cats/*physiology Crows/*physiology *Food Chain Introduced Species Marsupialia/*physiology Population Dynamics *Predatory Behavior Tasmania apex predators carcass use ecosystem function mesopredators scavenging trophic cascade; |
| Notes: | "MedlineCunningham, Calum X Johnson, Christopher N Barmuta, Leon A Hollings, Tracey Woehler, Eric J Jones, Menna E eng Research Support, Non-U.S. Gov't England 2018/11/30 Proc Biol Sci. 2018 Nov 28; 285(1892):20181582. doi: 10.1098/rspb.2018.1582" |
