Humans Alone Responsible for Tasmanian Tiger Extinction: Study

A new study by researchers from the University of Adelaide, Australia, finds that humans were solely responsible for the extinction of Australia's native predator, the Tasmanian tiger or thylacine.

The thylacine was a unique marsupial carnivore that resembled a dog with a striped coat and wolf-like head. The animal was found across all of Australia before European settlers arrived in the southern island state of Tasmania in 1803, reports Agence France-Presse news agency.

Between 1886 and 1909, the Tasmanian government had encouraged the people with bounties to hunt thylacines. After the bounty was lifted, only few thylacines were located. The last known thylacine was captured from the wild in 1933 and the animal died in Hobart Zoo in September 1936. Despite reports on various thylacine sightings, the carnivore was officially declared as extinct in 1986.

"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," project leader Thomas Prowse, from the University of Adelaide, said in a statement.

The extinction of the animals was linked to a distemper-like disease, but Prowse and his research team found that the disease was not the lead cause.

For their study, the researchers used a new population modeling approach to study the impact of the arrival of European sheep farmers on thylacine. The model simulated the direct effects of bounty hunting and habitat loss as well as the indirect effects of a reduction in thylacine's prey such as kangaroos and wallabies, due to human harvesting and competition from millions of introduced sheep.

"We showed that the negative impacts of European settlement were powerful enough that, even without any disease epidemic, the species couldn't escape extinction," said Prowse.

The findings of the study are published in the Journal of Animal Ecology.