Hunting drove Tasmanian tiger to extinction
Syndey, Feb 1 : Bounty hunting and not disease drove the Tasmanian tiger, a predator native to Australia, to extinction, says a new study.
Thylacine, the predator's scientific name, was a unique marsupial carnivore found throughout Tasmania before European settlement in 1803.
Between 1886 and 1909, the Tasmanian government encouraged people to hunt thylacines, paying bounties on over 2,000 thylacine carcasses.
Only a handful of animals were located after the bounty was lifted; the last known thylacine was captured from the wild in 1933, the Journal of Animal Ecology reports.
"Many people, however, believe that bounty hunting alone could not have driven the thylacine extinct, and claim that unknown epidemic may have been responsible," says the leader of the research project, Thomas Prowse, of the School of Earth and Environmental Sciences and the Environment Institute, University of Adelaide.
"We tested this claim by developing a 'metamodel' - a network of linked species models - that evaluated whether the combined impact of Europeans could have exterminated the thylacine, without any disease," adds Prowse, according to an Adelaide statement.
The math models used by conservation biologists to simulate the fate of threatened species under different management strategies traditionally neglect important interactions between species, which has now been incorporated by the researchers.
"The new model simulated the direct 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," 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, and that, even without any disease epidemic, the species couldn't escape extinction," Prowse said.