Dingo wrongly blamed for extinctions

Dingo , Fraser Island. Image - ogwens/Flickr

Dingo , Fraser Island. Image – ogwens/Flickr

Dingoes have been unjustly blamed for the extinctions on the Australian mainland of the Tasmanian tiger (or thylacine) and the Tasmanian devil, a University of Adelaide study has found.

In a paper published in the journal Ecology, the researchers say that despite popular belief that the Australian dingo was to blame for the demise of thylacines and devils on the mainland about 3000 years ago, in fact Aboriginal populations and a shift in climate were more likely responsible.

“Perhaps because the public perception of dingoes as ‘sheep-killers’ is so firmly entrenched, it has been commonly assumed that dingoes killed off the thylacines and devils on mainland Australia,” says researcher Dr Thomas Prowse, Research Associate in the School of Earth and Environmental Sciences and the Environment Institute.

“There was anecdotal evidence too: both thylacines and devils lasted for over 40,000 years following the arrival of humans in Australia; their mainland extinction about 3000 years ago was just after dingoes were introduced to Australia; and the fact that thylacines and devils persisted on Tasmania, which was never colonised by dingoes.

“However, and unfortunately for the dingo, most people have overlooked that about the same time as dingoes came along, the climate changed rather abruptly and Aboriginal populations were going through a major period of intensification in terms of population growth and technological advances.”

The researchers built a complex series of mathematical models to recreate the dynamic interaction between the main potential drivers of extinction (dingoes, climate and humans), the long-term response of herbivore prey, and the viability of the thylacine and devil populations.

The models included interactions and competition between predators as well as the influence of climate on vegetation and prey populations.

The simulations showed that while dingoes had some impact, growth and development in human populations, possibly intensified by climate change, was the most likely extinction driver.

“Our multi-species models showed that dingoes could reduce thylacine and devil populations through both competition and direct predation, but there was low probability that they could have been the sole extinction driver,” Dr Prowse says.

“Our results support the notion that thylacines and devils persisted on Tasmania not because the dingo was absent, but because human density remained low there and Tasmania was less affected by abrupt climate changes.”

The study ‘An ecological regime shift resulting from disrupted predator-prey interactions in Holocene Australia’ also involved Professors Corey Bradshaw and Barry Brook from the University of Adelaide’s Environment Institute and Professor Chris Johnson from the University of Tasmania.

Animal Evolution in Arid Australia Seminar Friday 3 May

Environment Institute member Professor Steven Cooper will present a seminar on his research ‘A New World Down Under: biodiversity and evolution of subterranean animals from the Australian arid zone’.Steven Cooper

About the speaker

Professor Steven Cooper is a Principal Researcher at the South Australian Museum and an affiliate at the University of Adelaide, where he is a member of the Australian Centre for Evolutionary Biology and Biodiversity, associated with the School of Earth and Environmental Sciences. His research investigates the diversity, evolution and molecular ecology of Australian fauna, with a strong focus on subterranean and groundwater invertebrate fauna from the arid zone of Australia.

Where: G25 Benham Laboratories, The University of Adelaide
When: Friday 3 May 2013
Time: 12pm-1pm
Cost: free

All welcome!

EI research shows broad-scale trends in climatic and environmental change in Australia over the past 30 ka

A new paper involving Environment Institute member John Tibby as well as L. Petherick (Queensland University of Technology & The University of Queensland), H. Bostock (National Institute of Water and Atmosphere), T.J. Cohen (The University of Wollongong), K. Fitzsimmons (Max Planck Institute for Evolutionary Anthropology), M.-S. Fletcher (Australian National University & University of Chile), P.Moss (University of Queensland), J. Reeves (University of Ballarat), S. Mooney (University of New South Wales), T. Barrows (University of Exeter), J. Kemp (Northumbria University), J. Jansen (Stockholm University), G. Nanson (University of Wollongong) and A. Dosseto (University of Wollongong) has recently been published in the the journal Quaternary Science Reviews.

John Tibby, one of the researchers involved on the paper

John Tibby, one of the researchers involved on the paper

The paper titled ”Climatic records over the past 30 ka from temperate Australia – a synthesis from the Oz-INTIMATE workgroup’ investigates broad-scale trends in climatic and environmental change in Australia over the past 30 ka.

Temperate Australia sits between the heat engine of the tropics and the cold Southern Ocean, encompassing a range of rainfall regimes and falling under the influence of different climatic drivers, despite this, researchers were able  to synthesise available palaeoenvironmental records and show that it is possible to gain insight into broader scale climatic and environmental variability without losing the intricacies of individual records.

Read the paper to find out more.