Why the Tasmanian tiger went extinct – new insights
|September 1, 2011||Posted by News under extinction|
It’s one of those situations where everything we knew about the tiger’s (thylacine wolf’s) extinction is true, but some new information rounds out the picture.
From “Tasmanian Tiger’s Jaw Was Too Small to Attack Sheep, Study Shows” (ScienceDaily, Aug. 31, 2011), we learn:
Australia’s iconic thylacine, or Tasmanian tiger, was hunted to death in the early Twentieth century for allegedly killing sheep; however, a new study published in the Zoological Society of London’s Journal of Zoology has found that the tiger had such weak jaws that its prey was probably no larger than a possum.
“Our research has shown that its rather feeble jaw restricted it to catching smaller, more agile prey,” said lead author Marie Attard, of the University of New South Wales Computational Biomechanics Research Group. “That’s an unusual trait for a large predator like that, considering its substantial 30 kg body mass and carnivorous diet. As for its supposed ability to take prey as large as sheep, our findings suggest that its reputation was at best overblown.
The weak jaw fills in a hole, certainly, in accounting for the marsupial wolf’s extinction. Had the wolf been able to kill sheep easily, it might not have gone extinct. Human persecution can greatly limit a well-adapted animal’s numbers and range without extinguishing it.
Using advanced computer modelling techniques, the UNSW research team were able to simulate various predatory behaviours, including biting, tearing and pulling, to predict patterns of stress in the skull of a thylacine and those of Australasia’s two largest remaining marsupial carnivores, the Tasmanian devil and the spotted-tailed quoll
“By comparing the skull performance of the extinct thylacine with those of closely related, living species we can predict the likely body size of its prey,” says the director of the Computational Biomechanics Research Group, Dr Stephen Wroe. “We can be pretty sure that thylacines were competing with other marsupial carnivores to prey on smaller mammals, such as bandicoots, wallabies and possums.
Another problem was the introduced wild dog or dingo, that was better adapted to killing large prey. The last known thylacine died in a Hobart zoo in 1936, though some are convinced that surviving thylacines may be found.
See also: Extinction: Limited genetic diversity may not doom Iberian lynx after all
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