Humans Alone Killed the Tasmanian Tiger; Thylacine Disease Debunked

It's a harrowing thought. Humans were the sole reason that the Tasmanian tiger went extinct in the 20^th century, according to a new study. The research shoots down the theory that disease also doomed the marsupial.

Known as thylacines, the Tasmanian tiger looked like a striped coyote. It ranged throughout most of the Australian island of Tasmania before Europeans settled there in 1803. A carnivore, the marsupial acted as a small-game hunter--like the coyotes of today. However, early Europeans believed that they would hunt their sheep and livestock, and so placed bounties on Tasmanian tigers. A recent study, though, shows that these animals' jaws were so weak, that they likely couldn't have brought down anything larger than a possum.

The study, published in the Journal of Animal Ecology, examined the thylacine extinction by using interaction modeling. Thomas Prowse and his team developed this mathematical model to study how the arrival of European sheep farmers impacted the Tasmanian tigers in ways that ranged from bounty hunting to a reduction of their prey.

The results showed that the negative impacts of European settlement were powerful enough that even without a disease epidemic, the species couldn't escape extinction.

It was once thought that the Tasmanian tigers were wiped off due to a combination of both disease and human impacts. Scientists theorized that an unknown epidemic must have been partly responsible, since humans couldn't have done enough damage. This new study, though, proves otherwise. Humans were the primary reason why the population crashed in the early 20^th century. The last known Tasmanian devil died in a zoo in 1936.

Currently, another Tasmanian animal is slowly edging toward extinction. The Tasmanian devil is being wiped out by a contagious cancer that's been able to spread more easily due to the species' low genetic diversity.