From the UNIVERSITY OF SYDNEY:
Feral animals pose major threat to Outback, climate change study finds
Australia has lost about 30 mammal species since European arrival
Scientists at the University of Sydney have analysed up to 22 years of long-term monitoring data on plants and animals in central Australia to project how changing rainfall and wildfire patterns, because of climate change, will influence desert wildlife.
The research from the University of Sydney’s School of Life and Environmental Sciences found there could be decreases in the cover of the dominant plant, spinifex, and a resulting decrease in seeding – and that introduced cats and foxes pose one of the major threats to seed-eating rodents.
Spinifex is a major habitat type across central Australia – from Queensland to Western Australia, including in the Simpson Desert where this study was conducted.
The findings are being published in the Royal Society’s journal Open Science.
Some estimates have suggested that up to one in six species are at risk from climate change. Predators can take advantage of more open habitats for hunting, which puts more pressure on wildlife.
Lead author Dr Aaron Greenville said their model suggested that if removing introduced cats and foxes, the rodent population would increase by almost one in 10.
“The dingo plays a complex positive role for wildlife in arid Australia,” said Dr Greenville.
The researchers, Dr Aaron Greenville, Professor Glenda Wardle and Professor Chris Dickman, in addition to working in the Faculty of Science, are affiliated with the Desert Ecology Research Group and the Terrestrial Ecosystem Research Network in Australia.
The paper, “Desert mammal populations are limited by introduced predators rather than future climate change”, will be available online at http://rsos.royalsocietypublishing.org/lookup/doi/10.1098/rsos.170384
Abstract (bold mine)
Climate change is predicted to place up to one in six species at risk of extinction in coming decades, but extinction probability is likely to be influenced further by biotic interactions such as predation. We use structural equation modelling to integrate results from remote camera trapping and long-term (17–22 years) regional-scale (8000 km2) datasets on vegetation and small vertebrates (greater than 38 880 captures) to explore how biotic processes and two key abiotic drivers influence the structure of a diverse assemblage of desert biota in central Australia. We use our models to predict how changes in rainfall and wildfire are likely to influence the cover and productivity of the dominant vegetation and the impacts of predators on their primary rodent prey over a 100-year timeframe. Our results show that, while vegetation cover may decline due to climate change, the strongest negative effect on prey populations in this desert system is top-down suppression from introduced predators