In one week, 10 Western Quolls (Dasyurus geoffroii) will be reintroduced to the Arid Recovery Reserve from Western Australia. They will be followed by an additional two quolls from the Ikara-Flinders Ranges in South Australia.
This reintroduction is the result of a lot of hard work and close interstate collaboration between Arid Recovery, the WA Department of Biodiversity, Conservation and Attractions (DBCA) and the SA Department for Environment and Water (DEW).
In this blog, we will answer some important questions about why we have chosen Western Quolls to be the next species reintroduced to our reserve and its implications.
What is a Western Quoll?
The Western Quoll is one of the largest carnivorous marsupials still extant on the Australian mainland. It is unique and more closely related to a Papua New Guinean quoll (Dasyurus spartacus – the Bronze Quoll) than any of Australia’s species. It is also the only arid-adapted quoll and once occurred in the area around Arid Recovery. Read more about the world’s six quoll species here.
The Western Quoll is threatened with extinction. Due to habitat clearing and alteration and predation by introduced foxes and feral cats, they survive in just 2% of their former range, which once covered 70% of Australia. As such, they are nationally listed as Vulnerable, and are a priority species for recovery by 2020 under the Federal Government’s Threatened Species Strategy.
Why are we reintroducing quolls to Arid Recovery?
There are several reasons why we are reintroducing the quolls to Arid Recovery. Firstly, as a top order predator they will hopefully perform a regulatory role in the reserve by preying on the burgeoning small mammal and Burrowing Bettong populations. These species are known prey items for the Western Quoll and are currently at high densities due to the low number of native predators in the reserve. Reintroducing a predator to the ecosystem will help recreate a balanced and entire natural ecosystem and more closely resemble pre-European settlement.
Another reason for reintroducing quolls is to improve the anti-predator response of our native species. Many of the species that we have reintroduced, such as stick-nest rats and bandicoots, come from offshore islands where they have been isolated from predators for thousands of years. Anti-predator behaviour can be lost quickly from island species leading to “island syndrome” where animals lose their fear response to predators. Placing animals into fenced reserves can exacerbate this making it hard to ever release animals out into areas where there are introduced predators. Reintroducing a native predator will hopefully improve the anti-predator response of our native species and help Arid Recovery achieve our goal of having animals beyond the fence.
Finally, releasing quolls may assist with the national conservation of the species by providing source populations for other release sites. Although Arid Recovery is probably too small to support a genetically viable population, we will be working with other organisations to conduct genetic swaps and manage the population at a national level.
Can they survive here?
Trials conducted by Dr Rebecca West and Dr Katherine Moseby found that the answer is a resounding yes. There’s plenty of food and shelter at Arid Recovery and quolls can successfully reproduce. In 2015, two females were introduced to the reserve as a trial. They survived and found suitable shelter and food, so in 2016 two males were released. One of the females fell pregnant and gave birth to four young. Two of those babies were translocated to the Flinders Ranges and a third remains in the reserve and has grown into a healthy adult.
Can we monitor them after release?
Yes, all of the quolls will be radio-collared and tracked every day by a dedicated Reintroduction Technical Officer. Our RTO, Melissa Jensen, is exceptionally qualified for the job, having conducted a PhD on the Western Quolls reintroduced to the Ikara-Flinders Ranges National Park in South Australia by DEW and the Foundation for Australia’s Most Endangered Species (FAME). The quolls will also be monitored with track transects, cage trapping, and camera traps.
What will they eat?
Since quolls are carnivores, they will prey upon the native species within the reserve. During our trials, we monitored what the quolls were eating through scat analysis. They mostly ate rodents (spinifex hopping mice), but also preyed on bettongs, bandicoots and invertebrates. Monitoring suggested that these species were not adversely impacted by the quolls.
Are Arid Recovery’s threatened species at risk?
No. We will be keeping 14km2 of our reserve ‘quoll-proof’, to ensure that bandicoots and stick-nest rats are protected. The Main Exclosure has been made quoll-proof through floppy-top fencing, electric wires and foot-netting (preventing animals digging holes underneath). Our threatened species will be closely monitored after the quoll release through track transects, nest monitoring and camera traps, both inside and outside the quoll-proof exclosure.
What about bettongs?
Arid Recovery’s population of Burrowing Bettongs is overabundant (read here). We know from our trials that quolls will eat bettongs, which will help to naturally control their population. Increasing the predation pressure on bettongs may also teach them better behaviours to avoid predators, potentially improving their survival chances outside of fences.
Will quolls help the ecosystem?
Yes. For the past 21 years, the Arid Recovery Reserve has had no large mammalian predator (except in our experimental feral paddocks). Bringing in the Western Quoll will reintroduce a keystone predator into the system and hopefully help to lower the bettong population to sustainable levels. This will reduce pressure on the native vegetation, providing more food and habitat for other species like the stick-nest rat. The changes to the ecosystem might look something like the famous Yellowstone wolves scenario, where bringing back wolves helped to control overabundant elk, which then let the vegetation grow back and other species like beavers thrive. Even rivers changed their course as the effect of this keystone predator cascaded through the ecosystem. Watch a video on it here, it’s an incredible story.
When does it start?
8th May 2018
Stay tuned to find out how it goes!
How can I help?
In the coming months we will be looking for helpers with keen eyes to identify juvenile quolls from their spot patterns as they emerge from their dens and are recorded on camera traps.
MEDIA ENQUIRIES: We ask media outlets to hold off reporting on this story until after the reintroduction has taken place. We will distribute a media release on the 9th of May with the full story and photos of the quolls as they explore their new home.