Kangaroo Island dunnart Critical monitoring of the last survivors
The Kangaroo Island dunnart (Sminthopsis aitkeni) is an endangered marsupial found only on Kangaroo Island, South Australia. It is the rarest of the 19 species of dunnarts, with numbers believed to be in the low hundreds.
Our long-term partnership with KI Land for Wildlife has been working to survey and protect this species for a number of years, beginning with a search for existing populations and continuing with revegetation, invasive species management and habitat surveys after last year’s bushfires.
With just a few survivors left, this next phase will ramp up the critical monitoring of the KI dunnart across its post-fire range to enable concentrated conservation efforts in the right areas.
ABOUT THE KANGAROO ISLAND DUNNART
The KI dunnart is a tiny, mouse-size marsupial smaller than your hand and weighing less than an AA battery. With a primary diet of insects, the dunnart plays an important role in balancing its environment.
Having evolved in its surrounding over many years, being endemic to the island, losing this species would have notable impacts outside of its extinction.
After two years of surveying for this elusive animal, our efforts were beginning to show rewards before the devastating bushfires of the 2019-20 summer. An already endangered species was sent plummeting to its end, initially feared extinct in the wake of the fires until remnant habitat was discovered.
Now, numbers are believed to sit somewhere between 50 individuals up to the low hundreds, making the KI dunnart one of the most critically endangered species in Australia.
PREVIOUS CONSERVATION WORK FOR THE KANGAROO ISLAND DUNNART
We partnered with KI Land for Wildlife (KILfW) in 2018 to begin the long search for this secretive marsupial, with little known about population numbers, territory range and the most pressing threats for its survival.
This initial work was a huge success, with more than 60 landholders engaged across the western part of the island, enabling surveying of more than 14,000 hectares of potential dunnart habitat. In the span of that project, some 50,000 camera-trap images were analysed!
The result? A total of 32 new Kangaroo Island dunnart records across six different locations. A fantastic outcome for a species rarely ever spotted in the wild.
Unfortunately, this brief moment of success was followed by some of the worst bushfires Australia has seen, and Kangaroo Island was not spared. Vast areas of known KI dunnart habitat were burnt to the ground.
This is not only devastating for the species through direct deaths from the fire, and a loss of food sources, but also by removing their natural vegetative cover. This opens them up to predation by feral cats that they may otherwise have been able to avoid.
In the wake of this tragedy, our next phase of conservation work with KILfW began, featuring revegetation efforts, surveys for surviving habitat through the use of helicopters and drones, replacement of equipment and ongoing management of invasive predators through trapping and shooting.
Thanks to our incredible donors, and support from the community, this has resulted in some initial success and has enabled the launch of the next phase of our work.
ANNOUNCING THE NEXT PHASE: CRITICAL MONITORING OF THE LAST SURVIVORS
Again partnering with KILfW, and the newly formed North West Conservation Alliance (NWCA), this new project focusses on post-fire surveys and monitoring of known populations. With a species so low in numbers, and so difficult to find in its natural habitat, ongoing surveys are one of the most important tools available.
The newly formed NWCA management zone will provide an area in which to improve our understanding of the threatened species following last year’s bushfires, and provide long-term protection. This zone sits within the largest, most important unburnt patch of western KI bushland.
This critical work will prevent the extinction, and aim to limit the decline, of the critically endangered KI dunnart. This in turn will support the conservation of a number of other priority species that inhabit the same area: KI echidna, bassian thrush, southern emu-wren and KI western whipbird.
HOW WILL WE SAVE THE KANGAROO ISLAND DUNNART?
Over the next 12 months, these extensive biodiversity surveys will take place across 10 private properties in western Kangaroo Island, seen in the survey map below.
A number of techniques will be used, including camera survey lines. These clever installments consist of 30cm-high flyscreen fences positioned in strategically chosen locations. The in situ barrier runs for 30m, held up by stakes, and a motion sensor camera is installed at either end.
These cameras, positioned half a metre from the mesh, capture footage of any animal that runs along the fence. Then, once a month, the camera files are downloaded and analysed for evidence of KI dunnarts.
Seasonal fauna trapping will continue across 18 sites within the NWCA management zone, with eight of those known to support dunnart populations. Along with the camera survey lines outlined above, trapping will involve pitfall traps, Elliott traps, cage traps and funnel traps.
From Spring this year through to Autumn 2022, surveys will look to get a holistic view of the state of the fauna in the region, and form a better understanding of the movement and numbers of the KI dunnart.
On top of surveys, our partners will work with private property owners to continue best practices for reducing the spread of the invasive Phytophthora cinnamomi - a mould that results in ‘root rot’, further damaging the already reduced habitat available to the dunnart.
THE IMPORTANCE OF KI DUNNART DATA
Any dunnarts trapped during this period will also have tissue samples taken in order to build a genetic database of the species.
This will provide invaluable insight into KI dunnart population dynamics, sex and breeding conditions and improve knowledge in life history, taxonomy and genetics. These activities build on the important conservation advice objectives outlined by the KI dunnart recovery team.
This phase of our Kangaroo Island dunnart conservation work will conclude by 30 June 2022, and aims to form 30 baseline ecological data sets.
This improved understanding of the species will cover 4,200ha in the NWCA management zone, and inform management decisions for species recovery efforts.
This work will involve:
- The operation of 10 camera trap survey sites, from set-up to ongoing maintenance and monitoring
- 18 seasonal fauna trap sites surveyed, and genetic samples collected and analysed
- A collation of baseline data using radio telemetry to broaden understanding of the dunnarts and their environment.
Images courtesy of Jody Gates, KI Land for Wildlife
WE NEED YOUR SUPPORT
This critical work is made possible by donations from supporters like you. Please visit the donation page for this project to help us save the Kangaroo Island dunnart from extinction.