Tasmanian devil’s decline is a boon for the spotted tail quoll

The rapid decline of the diseased-ravaged Tasmanian devil is a boon for another native animal, the spotted tail quoll.

A spotted tail quoll in a Tasmanian forest. Photo: David Hamilton

The rapid decline of the diseased ravaged Tasmanian devil is a boon for another native animal, the spotted tail quoll.

The number of Tasmanian devils has been decimated by the spread of a highly infectious facial cancer and this is having knock on effects through the Tasmanian eco-system, according to new research.

A global research team, including experts from the University of Tasmania, has found that the steep drop in Tasmanian devils – which are the eco-system’s top predator – has benefited spotted-tailed quolls, which are at the next level down in the predatory chain.

As a result, spotted-tailed quolls have changed their behaviour.

“We can see the activity of the spotted-tail quoll has shifted significantly in the regions where Tasmanian devils have severely reduced numbers,” said Professor Menna Jones from the University of Tasmania’s School of Natural Sciences.

“Spotted-tailed quolls have shifted their peak night-time activity, from pre-dawn to avoid devils, to early evening with low devils when most prey are active and hunting is the best.

“We found that with fewer devils, quolls are benefiting from more carrion and are spending more time feeding at carcasses.”

The genetic make up of the quolls is also changing as it responds to different natural selection pressures.

Genes relating to muscle development, movement and feeding behaviour have changed in areas of Tasmania where the number of devils has dropped dramatically, meaning that the quolls have less competition for food and less need to move around.

“There’s also changing evolutionary pressure on physical performance associated with escaping from devils and fertility of the quoll populations as devil numbers decline,” Professor Jones said.

The research team has spent 15 years collecting genetic data from 15 generations of quolls and the researchers hope that it will lead to better understanding of the evolutionary consequences of the decline in numbers of predator animals in many countries in the world.

The research is reported in the journal Nature Ecology and Evolution in a paper titled Disease-driven top predator decline affects mesopredator population genomic structure.