Declining devils force quoll evolution

By AG STAFF 12 February 2024
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Falling populations of Tassie devils – the Apple Isle’s apex predator – are affecting the evolution of spotted-tailed quolls, according to a new study.

Devil facial tumour disease (DFTD) has reduced the Tasmanian devil (Sarcophilus harrisii) population by about 80 per cent in the past three decades, increasing the activity of mesopredators – mid-range predators – such as spotted-tailed quolls (Dasyurus maculatus).

The two carnivorous marsupials share similar diets, although quolls tend to avoid devils, which are much larger and more aggressive. But in areas with high prevalence of DFTD (and small devil populations), quolls have access to more food resources, and, according to a new study published in Nature Ecology & Evolution in January 2024, are now travelling shorter distances to scavenge and breed. This is decreasing genetic exchange between individuals. 

tasmanian devil Related: Decline in Tassie devil populations disrupting food chain

Analysis of the genome of 345 individual quolls across 15 generations showed that quolls living in areas with low densities of Tasmanian devils had less genetic diversity compared with quolls living in areas with larger devil populations. Those quolls must travel further distances to find food and breeding partners.

The study also revealed gene variants associated with muscle development and movement in the less-mobile quolls living with smaller devil populations.

Related: A guide to all six species of quoll