Why are Tasmanian devils at greater risk of contagious cancers?
That was a key question during a recent international investigation into the species.
The investigation was led by the University of Cambridge, but researchers from the University of Tasmania were also involved.
The researchers discovered devils may be at greater risk because of their frequent face-biting as they fight for mates and food.
Face-biting was found to transfer the cancers from devil to devil, triggering similar face tumours, which then spread.
The transmissible cancers have killed 90 per cent of the species and caused them to be endangered.
Only eight naturally occurring transmissible cancers have been identified, two of which affect the species.
The researchers identified several similarities between the two cancers, which included the way they mutate, their origins and their response to particular drugs.
University of Cambridge senior researcher Elizabeth Murchison, who grew up in Tasmania, said the two cancers appeared within years of each other from different individuals.
When the first cancer appeared, they thought transmissible cancers were “extremely rare”, Ms Murchison said.
“But the emergence of the second one made us wonder whether Tasmanian devils might be particularly at risk for developing this kind of disease."
It appeared devils had problems with certain cell regulation, impeding their ability to repair wounds.
That meant the facial injuries could help spread and play a role in triggering the cancer, she said.
Researchers identified drugs that are effective against the cancer, and could aid the fight to save the species from extinction.
The research may help scientists develop a greater understanding about transmissible cancers.
A couple of years ago, only two transmissible cancers had been identified.
The discoveries hinted they could be more common than previously thought, she said.