Humans alone were responsible for the demise of Australia's iconic extinct native predator, the Tasmanian Tiger or thylacine, a new study led by the University of Adelaide has concluded.
Using a new population modelling approach, the study contradicts the widespread belief that disease must have been a factor in the thylacine's extinction.
The thylacine was a unique marsupial carnivore found throughout most of Tasmania before European settlement in 1803. Between 1886 and 1909, the Tasmanian government encouraged people to hunt thylacines and paid bounties on over 2000 thylacine carcasses. Only a handful of animals were located after the bounty was lifted and the last known thylacine was captured from the wild in 1933.
"Many people, however, believe that bounty hunting alone could not have driven the thylacine extinct and therefore claim that an unknown disease epidemic must have been responsible," says the project leader, Research Associate Dr Thomas Prowse, School of Earth and Environmental Sciences and the Environment Institute.
"We tested this claim by developing a 'metamodel' – a network of linked species models – that evaluated whether the combined impacts of Europeans could have exterminated the thylacine, without any disease."
The mathematical models used by conservation biologists to simulate the fate of threatened species under different management strategies (called population viability analysis or PVA) traditionally neglect important interactions between species. The researchers designed a new approach to PVA that included species interactions.
"The new model simulated the directs effects of bounty hunting and habitat loss and, importantly, also considered the indirect effects of a reduction in the thylacine's prey (kangaroos and wallabies) due to human harvesting and competition from millions of introduced sheep," Dr Prowse says.
"We found we could simulate the thylacine extinction, including the observed rapid population crash after 1905, without the need to invoke a mystery disease.
"We showed that the negative impacts of European settlement were powerful enough that, even without any disease epidemic, the species couldn't escape extinction."
University of Adelaide: http://www.adelaide.edu.au
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
The UK's chief scientist says the oceans face a serious and growing risk from man-made carbon emissions.
Modifying neurons to flash as electrical impulses pass along them lets researchers grow light-up brains in a dish and eavesdrop on their chatter
They lived on a remote dot of land in the middle of the Pacific, 2,300 miles (3,700 km) west of South America and 1,100 miles (1,770 km) from the closest island, erecting huge stone figures that still stare enigmatically from the hillsides.
In a bleak, treeless landscape high in the southern Peruvian Andes, bands of intrepid Ice Age people hunkered down in rudimentary dwellings and withstood frigid weather, thin air and other hardships.
A viral video shows people lauding fare billed as an "organic" fast-food option that was actually McDonald's. It wasn't just pranksters playing tricks on these poor folks, but maybe their brains, too.
Deinocheirus mirificus, or unusual horrible hand, had long, clawed forearms, a sail on its back and a duck-like bill
Open letter says claims made for brain games are not based on sound evidence and that playing them may have opposite effect
A significant Bronze Age pottery find is made during an archaeological dig on the east side of Lewis, in Scotland.
The oldest genome from a modern human reveals that modern humans with modern behaviour interbred with Neanderthals as they spread into Eurasia
Incredible night-vision videos of daring raids on farmers' fields are the first to show chimpanzees operating under cover of darkness