Did drought cause mainland thylacine decline?

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Thylacine numbers plummeted around 3,000 years ago. Image Credit: Benjamin A. Sheppard

Drought, rather than human hunting, may have wiped out the Tasmanian tiger on the Australian mainland.

While human hunting is thought to have been primarily responsible for wiping out the last few remaining thylacines in Tasmania during the early 20th century, a conclusive explanation for their disappearance from the mainland of Australia 2,000 years earlier has remained a lot more elusive.

Now though, by extracting DNA samples from fossil bones and museum specimens, researchers from the University of Adelaide’s Australian Center for Ancient DNA may have finally solved the mystery.

Their research involved creating the biggest dataset of thylacine DNA to date and then using that to build up a picture of how the animals’ population sizes varied over time.

The results suggested that, rather than being wiped out by human hunting or the introduction of wild dogs, the primary factor in the demise of the thylacine from the mainland of Australia was actually an extensive period of drought which decimated their numbers around 3,000 years ago.

“We also found evidence of a population crash, reducing numbers and genetic diversity of thylacines, in Tasmania around the same time,” said ACAD deputy director Jeremy Austin.

“Tasmania would have been somewhat shielded from the warmer, drier climate because of its higher rainfall, but it appears that this population was also affected by the El Nino event before starting to recover.”

Source: Phys.org 

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