September 16, 2007 12:00am
THE long-held belief Tasmanian tigers killed livestock is being challenged.
Using advanced computer modelling, an Australian research team has found that, while strong-jawed, the thylacine would have had trouble killing and eating prey any larger than itself. From about 1830 until 1909 the Tasmanian Government paid a 1-a-head bounty, prompted by complaints from farmers that tigers were taking their sheep.
The relentless hunting that followed is thought at least partly to blame for the tiger's extinction. University of New South Wales palaeontologist Stephen Wroe, who is leading the study, said because of its skull anatomy it was highly unlikely a Tasmanian tiger could take down a healthy adult sheep.
The research was primarily used to explain how the thylacine could have become extinct on the mainland 3000 years ago because it couldn't compete with introduced dingoes for larger prey.
But because of the tiger's genetic make-up, Dr Wroe said it might have been on the path to extinction in Tasmania even without the help of dingoes or European settlers. Past studies have found large carnivorous mammals have to take relatively large prey in order to replenish energy they use hunting.
If the tiger was restricted to smaller prey, it would have had to catch more in order to survive -- making it less efficient than other predators.
"By the time Europeans arrived on the island, it is estimated there were only 2000 to 5000 tigers left.
As farmland began to encroach on suitable hunting territory and tigers went further to find prey, it became harder to survive.
Farmers with guns, who killed about 2000 tigers, may have dealt what was an otherwise inevitable evolutionary blow.
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