Saving the northern quoll
30 September 2015
An omnivorous marsupial, the northern quoll grows to the size of a small cat.
Photo: Jonathan Webb
The northern quoll is one of Australia’s most iconic predators.
An omnivorous marsupial, the northern quoll is Australia’s smallest quoll, growing up to the size of a small cat. Sometimes, they are called “native cats.”
But they are dying. Fast.
Research has shown that the main threat to the northern quoll is its consumption of the toxic cane toad, which the quoll mistakes for a native frog and then suffers an unpleasant death.
Once common across northern Australia, today, the northern quoll is federally endangered, and has completely disappeared from Kakadu National Park.
At this stage, the northern quoll is facing imminent extinction in the Northern Territory.
Dr Jonathan Webb in the field with a northern quoll.
Photo: Damian Stanioch.
Luckily, UTS’s Dr Jonathan Webb has a solution.
A Wildlife Ecology lecturer, Dr Webb’s current research focuses on identifying casual factors responsible for declines of endangered fauna, and developing practical solutions to reverse such declines.
In the latest round of Australian Research Council (ARC) Linkage grants, he received a grant of $337, 775 over four years for his project: ‘Preventing and Reversing Population Declines of Northern Quolls.’
Dr Webb and Dr Ben Phillips from The University of Melbourne will work with industry partners Kakadu National Park, Australian Wildlife Conservancy, Northern Territory Department of Land and Resource Management and Territory Wildlife Park for the project.
With the additional assistance of several PhD students, they will attempt to stop quolls from becoming extinct in the Kimberley.
“Our project will trial several innovative methods to see if we can prevent quolls from going extinct in the Kimberley, and whether we can facilitate the recovery of quoll populations in areas where they are currently locally extinct, such as Kakadu National Park,” Dr Webb says.
The first part of the project involves reintroducing “toad-smart quolls” into Kakadu National Park.
In 2009, Dr Webb developed a “cane toad sausage” that consisted of a non-lethal toad paired with a nausea-inducing chemical.
After eating the bait, the quolls in the experiment would then associate the smell and taste of cane toads with illness and refuse to eat them, thus becoming toad-smart.
Photo: Jonathan Webb.
It is hoped that toad-smart quolls will be able to survive reintroduction into the wild and repopulate Kakadu National Park.
“A PhD student will help Territory Wildlife Park reintroduce toad-smart quolls to Kakadu, and Indigenous rangers from Kakadu National Park will help monitor the quoll population and will manage additional threats,” Dr Webb says.
The second part of the project involves training wild quolls to avoid cane toads prior to the toads invading the east Kimberley.
Now that Dr Webb and his team know that wild quolls will consume the cane toad sausages, the baits will be fed to quolls in the east Kimberley before the cane toad invasion.
“Australian Wildlife Conservancy will survey quoll populations before toads invade and will coordinate baiting prior to toad invasion,” Dr Webb says. “A PhD student will monitor quolls via radio-telemetry at control and baited sites, before and after toad invasion.”
If Dr Webb and his team can train enough wild quolls to avoid eating cane toads, they may be able to prevent the local extinction of the northern quoll.
They are, however, prepared with a back-up plan if baiting fails.
“If baiting fails, then we will bring quolls into captivity as an insurance population to prevent extinction,” Dr Webb says.
Dr Webb and his team’s research is not limited to the Kimberley, with PhD student Ella Kelly from the University of Melbourne currently exploring whether quolls in Queensland have genes for toad aversion.
“If Ella finds evidence for genes for toad avoidance, or rapid learning, then it might be feasible to cross QLD quolls with WA quolls, and reintroduce those quolls to areas where quolls are extinct…this is called assisted gene flow,” Dr Webb says.
The project could lead to a very novel solution to a major environmental issue, according to Dr Webb.
“Rather than trying to eradicate an invasive species, we’re using conditioned taste aversion to modify the behaviour of the predator.”
Dr Webb was one of four UTS Science lecturers to receive ARC funding for their projects.